ci: automatically close PRs from organization-owned forks

.github/workflows/close-organization-fork-prs.yml

@@ -0,0 +1,61 @@
+name: Close PRs from organization forks
+
+on:
+  pull_request_target:
+    types: [opened, reopened]
+
+permissions:
+  pull-requests: write
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: false
+
+jobs:
+  close-organization-fork-pr:
+    if: >-
+      github.event.pull_request.head.repo.owner.type == 'Organization' &&
+      github.event.pull_request.head.repo.id != github.event.pull_request.base.repo.id
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Explain the contribution policy and close the PR
+        uses: actions/github-script@v9
+        with:
+          script: |
+            const { data: pr } = await github.rest.pulls.get({
+              ...context.repo,
+              pull_number: context.issue.number,
+            });
+            const headRepo = pr.head.repo;
+            if (pr.state !== 'open' || !headRepo ||
+                headRepo.id === pr.base.repo.id || headRepo.owner.type !== 'Organization') {
+              return;
+            }
+
+            const marker = '<!-- organization-fork-policy -->';
+            const comments = await github.paginate(github.rest.issues.listComments, {
+              ...context.repo,
+              issue_number: pr.number,
+              per_page: 100,
+            });
+            const alreadyExplained = comments.some(comment =>
+              comment.user?.login === 'github-actions[bot]' && comment.body?.includes(marker));
+            if (!alreadyExplained) {
+              await github.rest.issues.createComment({
+                ...context.repo,
+                issue_number: pr.number,
+                body: [
+                  marker,
+                  'This repository requires contributions from forks to use a personal fork with **Allow edits from maintainers** enabled.',
+                  'GitHub does not support this option for organization-owned forks, so this PR is being closed automatically.',
+                  'Please open a new PR from a fork in your personal GitHub account and enable **Allow edits from maintainers** so maintainers can help update the branch.',
+                  'See [the GitHub documentation](https://docs.github.com/en/pull-requests/how-tos/work-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork).',
+                ].join('\n\n'),
+              });
+            }
+            await github.rest.pulls.update({
+              ...context.repo,
+              pull_number: pr.number,
+              state: 'closed',
+            });

CONTRIBUTING.md

@@ -12,6 +12,10 @@ If you want to update a third-party dependency, please open an issue first inste
 
 ## Pull Requests
 
+When contributing from a fork, use a fork under your personal GitHub account and enable **Allow edits from maintainers**. This lets maintainers make follow-up fixes directly on the PR branch.
+
+PRs from organization-owned forks are automatically closed when opened or reopened because GitHub does not support this maintainer-edit option for those forks. Submit the changes from a personal fork instead. See [GitHub's documentation](https://docs.github.com/en/pull-requests/how-tos/work-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork).
+
 Keep each PR focused on one clear change. Large or overly complex PRs are harder to review and may not be merged.
 
 Do not include test code or test scripts in commits or PRs. Keep them local and report verification results in the PR description.

docs/caching.md

@@ -2,6 +2,16 @@
 
 Caching methods accelerate diffusion inference by reusing intermediate computations when changes between steps are small.
 
+### Conditioning Cache
+
+Conditioning results are cached per model context using an LRU cache. The default
+capacity is **0 (disabled) for `sd-cli`** and **4 entries for `sd-server` and the C
+API**. Set `--conditioning-cache-size N` to change the limit; `0` disables caching.
+For example, `sd-cli -m model.safetensors -p "a cat" --conditioning-cache-size 4`
+enables the cache in the CLI. The C API option is
+`sd_ctx_params_t::conditioning_cache_size`, initialized by `sd_ctx_params_init()`.
+This cache is independent of the diffusion-step `--cache-mode` options below.
+
 ### Cache Modes
 
 | Mode | Target | Description |

docs/edit.md

@@ -26,6 +26,9 @@ Stable-diffusion.spp also supports basic Unet-based editing models like instruct
 
 ## Configuring Reference Modes (`--ref-image-args`)
 
+For a one-time input transform before reference presets and model processing,
+including cropping, padding, and resizing algorithms, see [Image preprocessing](./image_preprocessing.md).
+
 Different DiT-based editing models require different configurations to process reference images correctly (e.g., whether to use a Vision Language Model (VLM) encoder or pass VAE-encoded images directly to the DiT).
 
 To simplify this, we provide **Presets**. By default, the system automatically selects the best preset based on the model architecture. However, you can override this using the `--ref-image-args` argument.

docs/esrgan.md

@@ -2,6 +2,8 @@
 
 You can use ESRGAN—such as the model [RealESRGAN_x4plus_anime_6B.pth](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.2.4/RealESRGAN_x4plus_anime_6B.pth)—to upscale the generated images and improve their overall resolution and clarity.
 
+RGBA images, including Qwen Image 2.1 output, keep their alpha channel during model upscaling and hires fix. ESRGAN processes the RGB channels; the alpha channel is resized with bilinear interpolation and recombined with the upscaled image.
+
 - Specify the model path using the `--upscale-model PATH` parameter. example:
 
 ```bash

docs/image_preprocessing.md

@@ -0,0 +1,173 @@
+# Image preprocessing
+
+Use `--image-preprocess` to transform each image input once, before generation:
+
+```sh
+sd-cli ... \
+  --image-preprocess "target=init,mode=crop-resize,filter=lanczos,antialias=true" \
+  --image-preprocess "target=mask,filter=nearest-exact" \
+  --image-preprocess "target=ref,index=0,mode=fit-pad,width=768,height=768,filter=bicubic"
+```
+
+CLI and server image loaders decode at the original resolution. The generation
+entry point merges input defaults with user rules and prepares one transformed
+image per input. The original pipeline then consumes those images, including
+its mandatory canvas adaptation, reference resizing, and encoder preprocessing.
+
+```text
+native-resolution image
+  -> input defaults + user overrides
+  -> one input transform
+  -> original generation pipeline and model-specific processing
+```
+
+These rules do not override internal VAE, CLIP/VLM, ControlNet, or pixel-patch preprocessing.
+`--ref-image-args` retains its existing meaning and runs after this input transform.
+
+## Inputs and defaults
+
+| `target` | Input | Default geometry | Indexed? |
+| --- | --- | --- | --- |
+| `init` | img2img image or video first frame | Center crop to the generation aspect ratio, then resize | No |
+| `end` | Video last frame | Center crop, then resize | No |
+| `mask` | Inpainting mask | Inherit init geometry; otherwise center crop, then resize | No |
+| `control` | Control image | Center crop, then resize | No |
+| `ref` | Reference images | Preserve source dimensions | Yes |
+| `ip-adapter` | IP-Adapter image | Preserve source dimensions | No |
+| `id` | PhotoMaker identity images | Preserve source dimensions | Yes |
+| `control-frame` | Control video frames | Center crop, then resize | Yes |
+
+Canvas defaults use the aligned generation dimensions. Reference, IP-Adapter,
+and identity inputs use their original dimensions unless overridden. Default
+resampling is nearest for images and nearest-exact for masks.
+
+These defaults are shared by CLI, server, and C API. Moving geometry out of
+the loaders replaces the previous CLI/server BOX/sRGB resizing, so default
+pixels are not guaranteed to match earlier builds.
+
+Reference video and audio preprocessing are outside these image rules.
+Preprocessing options apply to `img_gen` and `vid_gen`, not standalone upscale
+or ADetailer mode. ADetailer clears the user's rules for its internal crops.
+
+## Rules
+
+Rules are comma-separated `key=value` lists. Repeat the CLI option or separate
+rules with semicolons. Every rule requires a `target` and at least one option.
+Rule syntax and input compatibility are checked when image/video generation
+starts. Unknown keys, invalid values, duplicate keys in a rule, missing images,
+and out-of-range indices cause generation to fail with an error log.
+
+Omit `index` to configure every image of that type; otherwise use a zero-based
+index. CLI directory inputs follow filename order. Indexed rules override
+type-wide rules field by field, regardless of order. At equal specificity,
+the last value for a field wins. `auto` selects the input preset.
+
+| `mode` | Input transform |
+| --- | --- |
+| `auto` | Use the input's default geometry |
+| `none` | Keep source dimensions without resizing, cropping, or padding |
+| `stretch` | Resize to the target dimensions |
+| `crop` | Crop a target-sized rectangle without resizing; fail if the source is too small |
+| `crop-resize` | Crop to the target aspect ratio, then resize |
+| `fit-pad` | Fit the entire image inside the target dimensions, preserving aspect ratio, then pad |
+
+`width` and `height` must be specified together as positive integers. They
+override the input transform's dimensions, not the generation or encoder size.
+For a native-size preset, specifying dimensions without a mode selects stretch.
+`mode=none` with explicit dimensions different from the source is contradictory
+and is rejected.
+
+`anchor=center|top|bottom|left|right` selects crop/padding placement.
+`pad_color=#RRGGBB` or `#RRGGBBAA` selects padding, defaulting to opaque black.
+A grayscale mask uses the first color component.
+
+`filter=auto|nearest|nearest-exact|bilinear|bicubic|lanczos` selects resampling.
+`antialias=auto|true|false` enables antialiasing automatically for filtered
+downscaling; explicit true requires bilinear, bicubic, or Lanczos.
+Filtered RGBA resizing uses premultiplied alpha.
+
+`canny=true|false` enables edge detection for any supported image target,
+defaulting to `false`. It runs once after geometry, before the original
+generation pipeline, including with `mode=none`. Grayscale, grayscale-alpha,
+RGB, and RGBA inputs are supported; alpha is preserved.
+
+Each input has its own Canny setting. Indexed rules can enable or disable it
+for individual references, identity images, or video control frames.
+
+```sh
+--image-preprocess "target=init,mode=fit-pad,canny=true"
+--image-preprocess "target=ref,index=0,mode=none,canny=true"
+--image-preprocess "target=control-frame,index=2,canny=true"
+```
+
+Init and mask sources must have the same dimensions. The mask inherits the
+init crop, resize, and padding coordinates, while retaining its own filter,
+padding value, and Canny setting. Conflicting mask geometry is rejected. An
+omitted mask remains absent until the original pipeline creates its default mask.
+
+## Downstream behavior
+
+`mode=none` only skips the input geometry transform. For example:
+
+```sh
+--image-preprocess "target=init,mode=none" \
+--image-preprocess "target=ref,mode=none"
+```
+
+The init image is still adapted to the generation canvas by the original
+pipeline. Reference images still follow `--ref-image-args` and model-specific
+resizing. CLIP retains its fixed input dimensions and normalization. HiDream-O1
+retains its original pixel-reference and visual preprocessing.
+
+Existing sharing between consumers is preserved: for example, Wan img2video
+uses the same adapted first frame for VAE conditioning and CLIP. High-resolution
+passes reuse the prepared images and apply their original size adaptation;
+they do not apply the user's crop a second time.
+
+To disable reference resizing before VAE encoding, use
+`--ref-image-args "resize_before_vae=false"` or the server field
+`"ref_image_args": "resize_before_vae=false"`. This is separate from
+`target=ref,mode=none`, which only skips input geometry. Model constraints
+still apply.
+
+## Server requests
+
+Native image/video requests and SDAPI accept `image_preprocess` as a string or
+an array of rule strings:
+
+```json
+{
+  "image_preprocess": [
+    "target=init,mode=fit-pad,filter=bicubic",
+    "target=mask,filter=nearest-exact",
+    "target=ref,index=0,mode=none"
+  ]
+}
+```
+
+OpenAI-compatible requests accept it through
+`<sd_cpp_extra_args>{...}</sd_cpp_extra_args>` in the prompt.
+Request rules replace server-default rules. Generation metadata records the
+user rules; image encodings and channel conventions are unchanged.
+
+## C API
+
+Set `image_preprocess` on the existing image/video generation parameters.
+The `generate_image()` and `generate_video()` signatures are unchanged:
+
+```c
+sd_img_gen_params_t params;
+sd_img_gen_params_init(&params);
+/* Set prompt, original-resolution input images, and generation options. */
+params.image_preprocess.rules = "target=init,mode=crop-resize,filter=lanczos;"
+                                "target=mask,filter=nearest-exact";
+bool ok = generate_image(ctx, &params, &images, &count);
+```
+
+Both generation parameter initializers set `image_preprocess.rules` to `NULL`,
+selecting input presets. Rule strings are borrowed for the synchronous call.
+The library owns temporary transformed pixels; caller images and arrays are
+not modified. Add `canny=true` to the desired target's rule in
+`image_preprocess.rules` to enable Canny.
+
+The parameter structs have grown; applications and bindings must be rebuilt.

docs/qwen_image_2.1.md

@@ -40,6 +40,14 @@ Pass the reference image with `-r` and describe the edit in `-p`. Vision weights
 
 For multiple reference images, repeat `-r` in the desired order, for example `-r first.png -r second.png`.
 
+### Prefix cache
+
+By default, the first denoising call for each fixed condition saves the text and reference-image keys and values from every transformer layer. Later calls only compute the target-image tokens. Positive and negative conditions use separate caches, which are released when sampling ends.
+
+The cache uses FP32 on all attention backends. For the default 32-layer model, a prefix of 4096 tokens takes about 4 GiB per condition, in addition to weights and working buffers. The runner accounts for the cache when checking the memory budget. If a cached execution runs out of memory, it releases the prefix caches, disables caching for the rest of that sampling run, and retries the full sequence once. Per-step conditioning extensions currently use the full-sequence path.
+
+Disable this optimization with `--model-args qwen_image_2_1_prefix_cache=false`. It reuses step-independent activations; numerical results can still differ slightly because the matrix sizes change.
+
 ### Alpha channel
 
 This model supports alpha channel output. As the model determines whether to output a regular image or with transparency through the prompt, according to [official recommendation](https://github.com/QwenLM/Qwen-Image-2.1#transparent-image-generation-rgba), use the following prompt format for better results:

examples/cli/README.md

@@ -14,6 +14,12 @@ equivalent to `--log-level verbose`. If repeated, the last logging option wins.
 For direct image repair or automatic post-generation YOLOv8 detection followed by cropped inpainting, see
 [ADetailer](../../docs/adetailer.md).
 
+Use repeatable `--image-preprocess` rules to select resizing, cropping, padding,
+and resampling separately for each image input. Add `canny=true` to any input
+rule for edge detection. See
+[Image preprocessing](../../docs/image_preprocessing.md) for input selectors,
+input defaults, downstream model processing, mask alignment, and examples.
+
 Metadata mode inspects PNG/JPEG container metadata without loading any model:
 
 ```bash

examples/cli/main.cpp

@@ -41,7 +41,6 @@ struct SDCliParams {
     std::string metadata_format = "text";
 
     sd_log_level_t log_level = SD_LOG_INFO;
-    bool canny_preprocess    = false;
     bool convert_name        = false;
 
     preview_t preview_method = PREVIEW_NONE;
@@ -107,10 +106,6 @@ struct SDCliParams {
         };
 
         options.bool_options = {
-            {"",
-             "--canny",
-             "apply canny preprocessor (edge detection)",
-             true, &canny_preprocess},
             {"",
              "--convert-name",
              "convert tensor name (for convert mode)",
@@ -268,7 +263,6 @@ struct SDCliParams {
             << "  metadata_format: \"" << metadata_format << "\",\n"
             << "  log_level: " << log_level_name(log_level) << ",\n"
             << "  color: " << (color ? "true" : "false") << ",\n"
-            << "  canny_preprocess: " << (canny_preprocess ? "true" : "false") << ",\n"
             << "  convert_name: " << (convert_name ? "true" : "false") << ",\n"
             << "  preview_method: " << previews_str[preview_method] << ",\n"
             << "  preview_interval: " << preview_interval << ",\n"
@@ -328,9 +322,7 @@ void sd_log_cb(enum sd_log_level_t level, const char* log, void* data) {
 
 bool load_images_from_dir(const std::string dir,
                           std::vector<SDImageOwner>& images,
-                          int expected_width  = 0,
-                          int expected_height = 0,
-                          int max_image_num   = 0) {
+                          int max_image_num = 0) {
     if (!fs::exists(dir) || !fs::is_directory(dir)) {
         LOG_ERROR("'%s' is not a valid directory\n", dir.c_str());
         return false;
@@ -358,7 +350,7 @@ bool load_images_from_dir(const std::string dir,
             int width             = 0;
             int height            = 0;
             int loaded_channel    = 0;
-            uint8_t* image_buffer = load_image_from_file(path.c_str(), width, height, loaded_channel, expected_width, expected_height);
+            uint8_t* image_buffer = load_image_from_file(path.c_str(), width, height, loaded_channel, 0, 0);
             if (image_buffer == nullptr) {
                 LOG_ERROR("load image from '%s' failed", path.c_str());
                 return false;
@@ -652,10 +644,11 @@ int main(int argc, const char* argv[]) {
 
     SDCliParams cli_params;
     SDContextParams ctx_params;
+    ctx_params.conditioning_cache_size = 0;
     SDGenerationParams gen_params;
 
-    parse_args(argc, argv, cli_params, ctx_params, gen_params);
     sd_set_log_callback(sd_log_cb, (void*)&cli_params);
+    parse_args(argc, argv, cli_params, ctx_params, gen_params);
 
     if (cli_params.mode == METADATA) {
         MetadataReadOptions options;
@@ -751,16 +744,8 @@ int main(int argc, const char* argv[]) {
 
     auto load_image_and_update_size = [&](const std::string& path,
                                           SDImageOwner& image,
-                                          bool resize_image    = true,
                                           int expected_channel = 3) -> bool {
-        int expected_width  = 0;
-        int expected_height = 0;
-        if (resize_image && gen_params.width_and_height_are_set()) {
-            expected_width  = gen_params.width;
-            expected_height = gen_params.height;
-        }
-
-        if (!load_sd_image_from_file(image.put(), path.c_str(), expected_width, expected_height, expected_channel)) {
+        if (!load_sd_image_from_file(image.put(), path.c_str(), 0, 0, expected_channel)) {
             LOG_ERROR("load image from '%s' failed", path.c_str());
             return false;
         }
@@ -783,7 +768,7 @@ int main(int argc, const char* argv[]) {
 
     if (gen_params.init_image_path.size() > 0) {
         const bool native_init = cli_params.mode == IMG_GEN || cli_params.mode == ADETAILER;
-        if (!load_image_and_update_size(gen_params.init_image_path, gen_params.init_image, true, native_init ? 0 : 3)) {
+        if (!load_image_and_update_size(gen_params.init_image_path, gen_params.init_image, native_init ? 0 : 3)) {
             return 1;
         }
     }
@@ -798,7 +783,7 @@ int main(int argc, const char* argv[]) {
         gen_params.ref_images.clear();
         for (auto& path : gen_params.ref_image_paths) {
             SDImageOwner ref_image({0, 0, 0, nullptr});
-            if (!load_image_and_update_size(path, ref_image, false, 0)) {
+            if (!load_image_and_update_size(path, ref_image, 0)) {
                 return 1;
             }
             gen_params.ref_images.push_back(std::move(ref_image));
@@ -839,41 +824,22 @@ int main(int argc, const char* argv[]) {
     if (gen_params.mask_image_path.size() > 0) {
         if (!load_sd_image_from_file(gen_params.mask_image.put(),
                                      gen_params.mask_image_path.c_str(),
-                                     gen_params.get_resolved_width(),
-                                     gen_params.get_resolved_height(),
+                                     0,
+                                     0,
                                      1)) {
             LOG_ERROR("load image from '%s' failed", gen_params.mask_image_path.c_str());
             return 1;
         }
-    } else {
-        sd_image_t generated_mask = {0, 0, 1, nullptr};
-        generated_mask.data       = (uint8_t*)malloc(gen_params.get_resolved_width() * gen_params.get_resolved_height());
-        if (generated_mask.data == nullptr) {
-            LOG_ERROR("malloc mask image failed");
-            return 1;
-        }
-        generated_mask.width  = gen_params.get_resolved_width();
-        generated_mask.height = gen_params.get_resolved_height();
-        memset(generated_mask.data, 255, gen_params.get_resolved_width() * gen_params.get_resolved_height());
-        gen_params.mask_image.reset(generated_mask);
     }
 
     if (gen_params.control_image_path.size() > 0) {
         if (!load_sd_image_from_file(gen_params.control_image.put(),
                                      gen_params.control_image_path.c_str(),
-                                     gen_params.get_resolved_width(),
-                                     gen_params.get_resolved_height())) {
+                                     0,
+                                     0)) {
             LOG_ERROR("load image from '%s' failed", gen_params.control_image_path.c_str());
             return 1;
         }
-        if (cli_params.canny_preprocess) {  // apply preprocessor
-            preprocess_canny(gen_params.control_image.get(),
-                             0.08f,
-                             0.08f,
-                             0.8f,
-                             1.0f,
-                             false);
-        }
     }
 
     if (gen_params.ip_adapter_image_path.size() > 0) {
@@ -890,8 +856,6 @@ int main(int argc, const char* argv[]) {
         gen_params.control_frames.clear();
         if (!load_images_from_dir(gen_params.control_video_path,
                                   gen_params.control_frames,
-                                  gen_params.get_resolved_width(),
-                                  gen_params.get_resolved_height(),
                                   gen_params.video_frames)) {
             return 1;
         }
@@ -900,10 +864,7 @@ int main(int argc, const char* argv[]) {
     if (!gen_params.pm_id_images_dir.empty()) {
         gen_params.pm_id_images.clear();
         if (!load_images_from_dir(gen_params.pm_id_images_dir,
-                                  gen_params.pm_id_images,
-                                  0,
-                                  0,
-                                  0)) {
+                                  gen_params.pm_id_images)) {
             return 1;
         }
     }

examples/common/common.cpp

@@ -518,7 +518,7 @@ ArgOptions SDContextParams::get_options() {
         {"",
          "--model-args",
          "extra model args, key=value list. Supports chroma_use_dit_mask, chroma_use_t5_mask, "
-         "chroma_t5_mask_pad, qwen_image_zero_cond_t",
+         "chroma_t5_mask_pad, qwen_image_zero_cond_t, qwen_image_2_1_prefix_cache",
          (int)',',
          &model_args},
         {"",
@@ -571,6 +571,10 @@ ArgOptions SDContextParams::get_options() {
          "number of threads to use during computation (default: -1). "
          "If threads <= 0, then threads will be set to the number of CPU physical cores",
          &n_threads},
+        {"",
+         "--conditioning-cache-size",
+         "maximum number of conditioning results cached per model context (default: " + std::to_string(conditioning_cache_size) + ", 0 disables caching)",
+         &conditioning_cache_size},
     };
 
     options.bool_options = {
@@ -822,6 +826,10 @@ bool SDContextParams::resolve(SDMode mode) {
 }
 
 bool SDContextParams::validate(SDMode mode) {
+    if (conditioning_cache_size < 0) {
+        LOG_ERROR("error: conditioning-cache-size must be non-negative");
+        return false;
+    }
     if (mode == CONVERT) {
         const bool has_convert_input = model_path.length() != 0 ||
                                        clip_l_path.length() != 0 ||
@@ -898,6 +906,7 @@ std::string SDContextParams::to_string() const {
     std::ostringstream oss;
     oss << "SDContextParams {\n"
         << "  n_threads: " << n_threads << ",\n"
+        << "  conditioning_cache_size: " << conditioning_cache_size << ",\n"
         << "  model_path: \"" << model_path << "\",\n"
         << "  clip_l_path: \"" << clip_l_path << "\",\n"
         << "  clip_g_path: \"" << clip_g_path << "\",\n"
@@ -992,6 +1001,7 @@ sd_ctx_params_t SDContextParams::to_sd_ctx_params_t(bool taesd_preview) {
     sd_ctx_params.pulid_weights_path              = pulid_weights_path.c_str();
     sd_ctx_params.tensor_type_rules               = tensor_type_rules.c_str();
     sd_ctx_params.n_threads                       = n_threads;
+    sd_ctx_params.conditioning_cache_size         = conditioning_cache_size;
     sd_ctx_params.wtype                           = wtype;
     sd_ctx_params.rng_type                        = rng_type;
     sd_ctx_params.sampler_rng_type                = sampler_rng_type;
@@ -1128,6 +1138,9 @@ ArgOptions SDGenerationParams::get_options() {
          "Key-value list to set up the way the reference images are processed (empty = auto-detect from model weigths)",
          (int)',',
          &ref_image_args},
+        {"", "--image-preprocess",
+         "Image preprocessing rule: target=init|end|mask|control|ref|ip-adapter|id|control-frame,index=N,mode=auto|none|stretch|crop|crop-resize|fit-pad,filter=auto|nearest|nearest-exact|bilinear|bicubic|lanczos,antialias=auto|true|false,width=W,height=H,anchor=center|top|bottom|left|right,pad_color=#RRGGBB[AA],canny=true|false. Repeat for multiple rules.",
+         (int)';', &image_preprocess},
     };
 
     options.int_options = {
@@ -1308,11 +1321,6 @@ ArgOptions SDGenerationParams::get_options() {
          "automatically increase the indices of references images based on the order they are listed (starting with 1).",
          true,
          &increase_ref_index},
-        {"",
-         "--disable-auto-resize-ref-image",
-         "disable auto resize of ref images",
-         false,
-         &auto_resize_ref_image},
         {"",
          "--circular",
          "enable circular padding on both axes for tileable output",
@@ -1870,8 +1878,6 @@ bool decode_base64_image(const std::string& encoded_input,
 static bool parse_image_json_field(const json& parent,
                                    const char* key,
                                    int channels,
-                                   int expected_width,
-                                   int expected_height,
                                    SDImageOwner& out_image) {
     if (!parent.contains(key)) {
         return true;
@@ -1883,14 +1889,12 @@ static bool parse_image_json_field(const json& parent,
     if (!parent.at(key).is_string()) {
         return false;
     }
-    return decode_base64_image(parent.at(key).get<std::string>(), channels, expected_width, expected_height, out_image);
+    return decode_base64_image(parent.at(key).get<std::string>(), channels, 0, 0, out_image);
 }
 
 static bool parse_image_array_json_field(const json& parent,
                                          const char* key,
                                          int channels,
-                                         int expected_width,
-                                         int expected_height,
                                          std::vector<SDImageOwner>& out_images) {
     if (!parent.contains(key)) {
         return true;
@@ -1909,7 +1913,7 @@ static bool parse_image_array_json_field(const json& parent,
             return false;
         }
         SDImageOwner image;
-        if (!decode_base64_image(item.get<std::string>(), channels, expected_width, expected_height, image)) {
+        if (!decode_base64_image(item.get<std::string>(), channels, 0, 0, image)) {
             return false;
         }
         out_images.push_back(std::move(image));
@@ -2008,6 +2012,29 @@ static bool resolve_model_file_from_dir(const std::string& model_name,
     return false;
 }
 
+bool SDGenerationParams::parse_image_preprocess_json(const std::string& json_str) {
+    const auto value = json::parse(json_str, nullptr, false);
+    std::string rules;
+    if (value.is_string()) {
+        rules = value.get<std::string>();
+    } else if (value.is_array()) {
+        for (const auto& item : value) {
+            if (!item.is_string()) {
+                LOG_ERROR("image_preprocess must contain rule strings");
+                return false;
+            }
+            if (!rules.empty())
+                rules += ";";
+            rules += item.get<std::string>();
+        }
+    } else {
+        LOG_ERROR("image_preprocess must be a string or array of strings");
+        return false;
+    }
+    image_preprocess = std::move(rules);
+    return true;
+}
+
 bool SDGenerationParams::from_json_str(
     const std::string& json_str,
     const std::function<std::string(const std::string&)>& lora_path_resolver) {
@@ -2019,6 +2046,9 @@ bool SDGenerationParams::from_json_str(
         return false;
     }
 
+    if (j.contains("image_preprocess") && !parse_image_preprocess_json(j["image_preprocess"].dump()))
+        return false;
+
     auto load_if_exists = [&](const char* key, auto& out) {
         if (j.contains(key)) {
             using T = std::decay_t<decltype(out)>;
@@ -2056,6 +2086,7 @@ bool SDGenerationParams::from_json_str(
     load_if_exists("cache_mode", cache_mode);
     load_if_exists("cache_option", cache_option);
     load_if_exists("scm_mask", scm_mask);
+    load_if_exists("ref_image_args", ref_image_args);
 
     load_if_exists("clip_skip", clip_skip);
     load_if_exists("width", width);
@@ -2073,7 +2104,6 @@ bool SDGenerationParams::from_json_str(
     load_if_exists("moe_boundary", moe_boundary);
     load_if_exists("vace_strength", vace_strength);
 
-    load_if_exists("auto_resize_ref_image", auto_resize_ref_image);
     load_if_exists("increase_ref_index", increase_ref_index);
     load_if_exists("embed_image_metadata", embed_image_metadata);
 
@@ -2217,37 +2247,23 @@ bool SDGenerationParams::from_json_str(
         LOG_ERROR("invalid lora");
         return false;
     }
-    if (!parse_image_json_field(j, "init_image", 0, width, height, init_image)) {
-        LOG_ERROR("invalid init_image");
+    auto load_image = [&](const char* key, int channels, SDImageOwner& image) {
+        if (!parse_image_json_field(j, key, channels, image)) {
+            LOG_ERROR("invalid %s", key);
+            return false;
+        }
+        return true;
+    };
+    if (!load_image("init_image", 0, init_image) ||
+        !load_image("end_image", 3, end_image) ||
+        !load_image("mask_image", 1, mask_image) ||
+        !load_image("control_image", 3, control_image) ||
+        !load_image("ip_adapter_image", 3, ip_adapter_image)) {
         return false;
     }
-    if (!parse_image_json_field(j, "end_image", 3, width, height, end_image)) {
-        LOG_ERROR("invalid end_image");
-        return false;
-    }
-    if (!parse_image_array_json_field(j,
-                                      "ref_images",
-                                      0,
-                                      auto_resize_ref_image ? width : 0,
-                                      auto_resize_ref_image ? height : 0,
-                                      ref_images)) {
-        LOG_ERROR("invalid ref_images");
-        return false;
-    }
-    if (!parse_image_array_json_field(j, "control_frames", 3, width, height, control_frames)) {
-        LOG_ERROR("invalid control_frames");
-        return false;
-    }
-    if (!parse_image_json_field(j, "mask_image", 1, width, height, mask_image)) {
-        LOG_ERROR("invalid mask_image");
-        return false;
-    }
-    if (!parse_image_json_field(j, "control_image", 3, width, height, control_image)) {
-        LOG_ERROR("invalid control_image");
-        return false;
-    }
-    if (!parse_image_json_field(j, "ip_adapter_image", 3, width, height, ip_adapter_image)) {
-        LOG_ERROR("invalid ip_adapter_image");
+    if (!parse_image_array_json_field(j, "ref_images", 0, ref_images) ||
+        !parse_image_array_json_field(j, "control_frames", 3, control_frames)) {
+        LOG_ERROR("invalid input image array");
         return false;
     }
 
@@ -2491,6 +2507,10 @@ bool SDGenerationParams::resolve(const std::string& lora_model_dir, const std::s
 }
 
 bool SDGenerationParams::validate(SDMode mode) {
+    if (!image_preprocess.empty() && mode != IMG_GEN && mode != VID_GEN) {
+        LOG_ERROR("--image-preprocess requires img_gen or vid_gen mode");
+        return false;
+    }
     if (batch_count <= 0) {
         LOG_ERROR("error: batch_count must be greater than 0");
         return false;
@@ -2666,14 +2686,6 @@ sd_img_gen_params_t SDGenerationParams::to_sd_img_gen_params_t() {
         pulid_id_weight,
     };
 
-    if (!auto_resize_ref_image) {
-        if (!ref_image_args.empty()) {
-            ref_image_args += ",";
-        }
-        ref_image_args += "resize_before_vae=0";
-        LOG_WARN("Notice: --disable-auto-resize-ref-image is deprecated. Use --ref-image-args \"resize_before_vae=off\" instead.");
-    }
-
     if (increase_ref_index) {
         if (!ref_image_args.empty()) {
             ref_image_args += ",";
@@ -2721,6 +2733,7 @@ sd_img_gen_params_t SDGenerationParams::to_sd_img_gen_params_t() {
     params.hires.custom_sigmas_count = static_cast<int>(hires_custom_sigmas.size());
     params.circular_x                = circular || circular_x;
     params.circular_y                = circular || circular_y;
+    params.image_preprocess          = {image_preprocess.c_str()};
     return params;
 }
 
@@ -2823,6 +2836,7 @@ sd_vid_gen_params_t SDGenerationParams::to_sd_vid_gen_params_t() {
     params.hires.custom_sigmas_count = static_cast<int>(hires_custom_sigmas.size());
     params.circular_x                = circular || circular_x;
     params.circular_y                = circular || circular_y;
+    params.image_preprocess          = {image_preprocess.c_str()};
     return params;
 }
 
@@ -2879,7 +2893,8 @@ std::string SDGenerationParams::to_string() const {
         << "  ref_video_audio_paths: " << vec_str_to_string(ref_video_audio_paths) << ",\n"
         << "  ref_audio_paths: " << vec_str_to_string(ref_audio_paths) << ",\n"
         << "  control_video_path: \"" << control_video_path << "\",\n"
-        << "  auto_resize_ref_image: " << (auto_resize_ref_image ? "true" : "false") << ",\n"
+        << "  image_preprocess: " << image_preprocess << ",\n"
+        << "  ref_image_args: " << ref_image_args << ",\n"
         << "  increase_ref_index: " << (increase_ref_index ? "true" : "false") << ",\n"
         << "  pm_id_images_dir: \"" << pm_id_images_dir << "\",\n"
         << "  pm_id_embed_path: \"" << pm_id_embed_path << "\",\n"
@@ -3030,12 +3045,13 @@ std::string build_sdcpp_image_metadata_json(const SDContextParams& ctx_params,
     set_json_basename_if_not_empty(models, "control_net", ctx_params.control_net_path);
     root["models"] = std::move(models);
 
-    root["clip_skip"]             = gen_params.clip_skip;
-    root["strength"]              = gen_params.strength;
-    root["control_strength"]      = gen_params.control_strength;
-    root["ip_adapter_strength"]   = gen_params.ip_adapter_strength;
-    root["auto_resize_ref_image"] = gen_params.auto_resize_ref_image;
-    root["increase_ref_index"]    = gen_params.increase_ref_index;
+    root["clip_skip"]           = gen_params.clip_skip;
+    root["strength"]            = gen_params.strength;
+    root["control_strength"]    = gen_params.control_strength;
+    root["ip_adapter_strength"] = gen_params.ip_adapter_strength;
+    root["ref_image_args"]      = gen_params.ref_image_args;
+    root["image_preprocess"]    = gen_params.image_preprocess;
+    root["increase_ref_index"]  = gen_params.increase_ref_index;
     if (mode == VID_GEN) {
         root["video"] = {
             {"frame_count", gen_params.video_frames},

examples/common/common.h

@@ -116,7 +116,8 @@ bool decode_base64_image(const std::string& encoded_input,
                          SDImageOwner& out_image);
 
 struct SDContextParams {
-    int n_threads = -1;
+    int n_threads               = -1;
+    int conditioning_cache_size = 4;
     std::string model_path;
     std::string clip_l_path;
     std::string clip_g_path;
@@ -200,18 +201,17 @@ struct SDGenerationParams {
     std::string ad_prompt;
     std::string ad_negative_prompt;
     std::string extra_ad_args;
-    int clip_skip              = -1;  // <= 0 represents unspecified
-    int width                  = -1;
-    int height                 = -1;
-    int batch_count            = 1;
-    int qwen_image_layers      = 3;
-    int64_t seed               = 42;
-    float strength             = 0.75f;
-    float control_strength     = 0.9f;
-    float ip_adapter_strength  = 1.0f;
-    bool auto_resize_ref_image = true;
-    bool increase_ref_index    = false;
-    bool embed_image_metadata  = true;
+    int clip_skip             = -1;  // <= 0 represents unspecified
+    int width                 = -1;
+    int height                = -1;
+    int batch_count           = 1;
+    int qwen_image_layers     = 3;
+    int64_t seed              = 42;
+    float strength            = 0.75f;
+    float control_strength    = 0.9f;
+    float ip_adapter_strength = 1.0f;
+    bool increase_ref_index   = false;
+    bool embed_image_metadata = true;
 
     std::string init_image_path;
     std::string end_image_path;
@@ -247,6 +247,7 @@ struct SDGenerationParams {
     std::string extra_tiling_args;
 
     std::string ref_image_args;
+    std::string image_preprocess;
 
     std::string pm_id_images_dir;
     std::string pm_id_embed_path;
@@ -310,6 +311,7 @@ struct SDGenerationParams {
     ArgOptions get_options();
     bool from_json_str(const std::string& json_str,
                        const std::function<std::string(const std::string&)>& lora_path_resolver = {});
+    bool parse_image_preprocess_json(const std::string& json_str);
     bool initialize_cache_params();
     void extract_and_remove_lora(const std::string& lora_model_dir);
     bool width_and_height_are_set() const;

examples/server/api.md

@@ -148,6 +148,19 @@ Native extension fields:
 
 - any `sdcpp API` fields embedded through `sd_cpp_extra_args` inside `prompt`
 
+Uploaded images are decoded at their original dimensions. The first decoded
+image establishes the generation dimensions if `size` is omitted. Input
+geometry follows `image_preprocess`: references preserve their dimensions by
+default, while init and mask use the generation canvas preset.
+
+Reference encoding then follows model presets and `ref_image_args`. To skip
+input geometry for references and disable resizing before VAE encoding, include
+this in `prompt`:
+
+```text
+edit this image <sd_cpp_extra_args>{"image_preprocess":"target=ref,mode=none","ref_image_args":"resize_before_vae=false"}</sd_cpp_extra_args>
+```
+
 Response fields:
 
 | Field | Type | Notes |
@@ -526,7 +539,7 @@ LTX and Wan preserve causal state between temporal tiles. Hunyuan Video and TAEH
 | Field | Type |
 | --- | --- |
 | `batch_count` | `integer` |
-| `auto_resize_ref_image` | `boolean` |
+| `ref_image_args` | `string` |
 | `increase_ref_index` | `boolean` |
 | `control_strength` | `number` |
 | `ip_adapter_strength` | `number` |
@@ -653,7 +666,7 @@ Example:
   "strength": 0.75,
   "seed": -1,
   "batch_count": 1,
-  "auto_resize_ref_image": true,
+  "ref_image_args": "",
   "increase_ref_index": false,
   "control_strength": 0.9,
   "ip_adapter_strength": 1.0,
@@ -728,6 +741,17 @@ Example:
 
 ### Image Encoding Rules
 
+Native image/video requests and SDAPI accept `image_preprocess` as a rule string
+or array of rule strings. OpenAI-compatible requests can supply it in
+`sd_cpp_extra_args`. See [Image preprocessing](../../docs/image_preprocessing.md)
+for one-time input geometry, native-resolution decoding, mask alignment, and
+`canny=true` for edge detection on any supported image input.
+
+Image generation also accepts `ref_image_args` as a string (for example,
+`"resize_before_vae=false"`) in native and SDAPI requests, or through
+`sd_cpp_extra_args` in OpenAI-compatible requests. It controls downstream
+reference encoding and is independent of input geometry rules.
+
 Any image field accepts:
 
 - a raw base64 string, or
@@ -763,7 +787,8 @@ Top-level scalar fields:
 | `strength` | `number` |
 | `seed` | `integer` |
 | `batch_count` | `integer` |
-| `auto_resize_ref_image` | `boolean` |
+| `ref_image_args` | `string` |
+| `image_preprocess` | `string \| array<string>` |
 | `increase_ref_index` | `boolean` |
 | `control_strength` | `number` |
 | `ip_adapter_strength` | `number` |

examples/server/main.cpp

@@ -76,9 +76,9 @@ int main(int argc, const char** argv) {
     SDSvrParams svr_params;
     SDContextParams ctx_params;
     SDGenerationParams default_gen_params;
-    parse_args(argc, argv, svr_params, ctx_params, default_gen_params);
 
     sd_set_log_callback(sd_log_cb, (void*)&svr_params);
+    parse_args(argc, argv, svr_params, ctx_params, default_gen_params);
 
     LOG_VERBOSE("version: %s", version_string().c_str());
     LOG_VERBOSE("%s", sd_get_system_info());

examples/server/routes_openai.cpp

@@ -157,6 +157,7 @@ static bool build_openai_edit_request(const httplib::Request& req,
     request.gen_params.height      = height;
     request.gen_params.batch_count = n;
 
+    std::string sd_cpp_extra_args_str = extract_and_remove_sd_cpp_extra_args(request.gen_params.prompt);
     for (auto& bytes : images_bytes) {
         int img_w            = 0;
         int img_h            = 0;
@@ -165,7 +166,8 @@ static bool build_openai_edit_request(const httplib::Request& req,
              reinterpret_cast<const char*>(bytes.data()),
              static_cast<int>(bytes.size()),
              img_w, img_h, resolved_channel,
-             0, 0, 0);
+             0, 0,
+             0);
         if (raw_pixels == nullptr) {
             continue;
         }
@@ -175,23 +177,10 @@ static bool build_openai_edit_request(const httplib::Request& req,
         request.gen_params.set_width_and_height_if_unset(image_owner.get().width, image_owner.get().height);
 
         if (is_first_ref_image) {
-            int init_w = 0;
-            int init_h = 0;
-            if (request.gen_params.width_and_height_are_set()) {
-                init_w = request.gen_params.width;
-                init_h = request.gen_params.height;
-            }
-
-            int init_img_w            = 0;
-            int init_img_h            = 0;
-            int init_resolved_channel = 0;
-            uint8_t* init_pixels     = load_image_from_memory(
-                 reinterpret_cast<const char*>(bytes.data()),
-                 static_cast<int>(bytes.size()),
-                 init_img_w, init_img_h, init_resolved_channel,
-                 init_w, init_h, 0);
-            if (init_pixels != nullptr) {
-                request.gen_params.init_image.reset({(uint32_t)init_img_w, (uint32_t)init_img_h, (uint32_t)init_resolved_channel, init_pixels});
+            request.gen_params.init_image = image_owner;
+            if (request.gen_params.init_image.get().data == nullptr) {
+                error_message = "could not allocate init image";
+                return false;
             }
         }
 
@@ -199,12 +188,6 @@ static bool build_openai_edit_request(const httplib::Request& req,
     }
 
     if (!mask_bytes.empty()) {
-        int expected_width  = 0;
-        int expected_height = 0;
-        if (request.gen_params.width_and_height_are_set()) {
-            expected_width  = request.gen_params.width;
-            expected_height = request.gen_params.height;
-        }
         int mask_w       = 0;
         int mask_h       = 0;
         int mask_channel = 0;
@@ -213,7 +196,7 @@ static bool build_openai_edit_request(const httplib::Request& req,
             reinterpret_cast<const char*>(mask_bytes.data()),
             static_cast<int>(mask_bytes.size()),
             mask_w, mask_h, mask_channel,
-            expected_width, expected_height, 1);
+            0, 0, 1);
         request.gen_params.mask_image.reset({(uint32_t)mask_w, (uint32_t)mask_h, 1, mask_raw});
         const sd_image_t& mask_image = request.gen_params.mask_image.get();
         request.gen_params.set_width_and_height_if_unset(mask_image.width, mask_image.height);
@@ -226,7 +209,6 @@ static bool build_openai_edit_request(const httplib::Request& req,
         });
     }
 
-    std::string sd_cpp_extra_args_str = extract_and_remove_sd_cpp_extra_args(request.gen_params.prompt);
     if (!sd_cpp_extra_args_str.empty() && !request.gen_params.from_json_str(sd_cpp_extra_args_str)) {
         error_message = "invalid sd_cpp_extra_args";
         return false;

examples/server/routes_sdapi.cpp

@@ -80,17 +80,6 @@ static enum sample_method_t get_sdapi_sample_method(std::string name) {
     return it != hardcoded.end() ? it->second : SAMPLE_METHOD_COUNT;
 }
 
-static void assign_solid_mask(SDImageOwner& mask_owner, int width, int height) {
-    const size_t pixel_count = static_cast<size_t>(width) * static_cast<size_t>(height);
-    uint8_t* raw_mask        = static_cast<uint8_t*>(malloc(pixel_count));
-    if (raw_mask == nullptr) {
-        mask_owner.reset({0, 0, 1, nullptr});
-        return;
-    }
-    std::memset(raw_mask, 255, pixel_count);
-    mask_owner.reset({(uint32_t)width, (uint32_t)height, 1, raw_mask});
-}
-
 static bool build_sdapi_img_gen_request(const json& j,
                                         ServerRuntime& runtime,
                                         bool img2img,
@@ -193,15 +182,25 @@ static bool build_sdapi_img_gen_request(const json& j,
         }
     }
 
-    if (img2img) {
-        const int expected_width  = request.gen_params.width_and_height_are_set() ? request.gen_params.width : 0;
-        const int expected_height = request.gen_params.width_and_height_are_set() ? request.gen_params.height : 0;
+    if (j.contains("ref_image_args")) {
+        if (!j["ref_image_args"].is_string()) {
+            error_message = "ref_image_args must be a string";
+            return false;
+        }
+        request.gen_params.ref_image_args = j["ref_image_args"].get<std::string>();
+    }
 
+    if (j.contains("image_preprocess") && !request.gen_params.parse_image_preprocess_json(j["image_preprocess"].dump())) {
+        error_message = "invalid image_preprocess";
+        return false;
+    }
+
+    if (img2img) {
         if (j.contains("init_images") && j["init_images"].is_array() && !j["init_images"].empty()) {
             if (decode_base64_image(j["init_images"][0].get<std::string>(),
                                     0,
-                                    expected_width,
-                                    expected_height,
+                                    0,
+                                    0,
                                     request.gen_params.init_image)) {
                 const sd_image_t& image = request.gen_params.init_image.get();
                 request.gen_params.set_width_and_height_if_unset(image.width, image.height);
@@ -211,8 +210,8 @@ static bool build_sdapi_img_gen_request(const json& j,
         if (j.contains("mask") && j["mask"].is_string()) {
             if (decode_base64_image(j["mask"].get<std::string>(),
                                     1,
-                                    expected_width,
-                                    expected_height,
+                                    0,
+                                    0,
                                     request.gen_params.mask_image)) {
                 const sd_image_t& image = request.gen_params.mask_image.get();
                 request.gen_params.set_width_and_height_if_unset(image.width, image.height);
@@ -225,9 +224,7 @@ static bool build_sdapi_img_gen_request(const json& j,
                 }
             }
         } else {
-            const int resolved_width  = request.gen_params.get_resolved_width();
-            const int resolved_height = request.gen_params.get_resolved_height();
-            assign_solid_mask(request.gen_params.mask_image, resolved_width, resolved_height);
+            request.gen_params.mask_image.reset({0, 0, 1, nullptr});
         }
 
         float denoising_strength = j.value("denoising_strength", -1.f);
@@ -244,12 +241,7 @@ static bool build_sdapi_img_gen_request(const json& j,
             SDImageOwner image_owner;
             if (decode_base64_image(extra_image.get<std::string>(),
                                     0,
-                                    request.gen_params.auto_resize_ref_image && request.gen_params.width_and_height_are_set()
-                                        ? request.gen_params.width
-                                        : 0,
-                                    request.gen_params.auto_resize_ref_image && request.gen_params.width_and_height_are_set()
-                                        ? request.gen_params.height
-                                        : 0,
+                                    0, 0,
                                     image_owner)) {
                 const sd_image_t& image = image_owner.get();
                 request.gen_params.set_width_and_height_if_unset(image.width, image.height);

examples/server/routes_sdcpp.cpp

@@ -127,7 +127,8 @@ static json make_img_gen_defaults_json(const SDGenerationParams& defaults, const
         {"seed", defaults.seed},
         {"batch_count", defaults.batch_count},
         {"qwen_image_layers", defaults.qwen_image_layers},
-        {"auto_resize_ref_image", defaults.auto_resize_ref_image},
+        {"ref_image_args", defaults.ref_image_args},
+        {"image_preprocess", defaults.image_preprocess},
         {"increase_ref_index", defaults.increase_ref_index},
         {"control_strength", defaults.control_strength},
         {"ip_adapter_strength", defaults.ip_adapter_strength},
@@ -153,6 +154,7 @@ static json make_vid_gen_defaults_json(const SDGenerationParams& defaults, const
         {"strength", defaults.strength},
         {"seed", defaults.seed},
         {"video_frames", defaults.video_frames},
+        {"image_preprocess", defaults.image_preprocess},
         {"fps", defaults.fps},
         {"moe_boundary", defaults.moe_boundary},
         {"vace_strength", defaults.vace_strength},

include/stable-diffusion.h

@@ -247,6 +247,7 @@ typedef struct {
     float attn_scale;                // Override flash-attention K/V scaling; 0 keeps the model default
     const char* tokenizer;           // tokenizer.json path or main=FILE,clip-l=FILE,clip-g=FILE assignments; required for PiD and Lens
     bool sage_attn;
+    int conditioning_cache_size;  // Maximum cached conditioning entries per context; 0 disables caching (default: 4)
 } sd_ctx_params_t;
 
 typedef struct {
@@ -263,6 +264,11 @@ typedef struct {
     uint8_t* data;
 } sd_image_t;
 
+typedef struct {
+    // Semicolon-separated target=...,key=value rules. NULL preserves defaults.
+    const char* rules;
+} sd_image_preprocess_params_t;
+
 typedef struct {
     sd_image_t* frames;
     int frame_count;
@@ -410,6 +416,7 @@ typedef struct {
     int qwen_image_layers;
     bool circular_x;
     bool circular_y;
+    sd_image_preprocess_params_t image_preprocess;
 } sd_img_gen_params_t;
 
 typedef struct {
@@ -443,6 +450,7 @@ typedef struct {
     sd_hires_params_t hires;
     bool circular_x;
     bool circular_y;
+    sd_image_preprocess_params_t image_preprocess;
 } sd_vid_gen_params_t;
 
 typedef struct sd_ctx_t sd_ctx_t;

src/conditioning/conditioner.hpp

@@ -3166,6 +3166,7 @@ struct LLMEmbedder : public Conditioner {
             int64_t tag_count    = static_cast<int64_t>(tags.size());
             result.c_token_types = sd::Tensor<int32_t>({tag_count}, std::move(tags));
         }
+
         return result;
     }
 };

src/conditioning/conditioning_cache.h

@@ -0,0 +1,107 @@
+#ifndef __SD_CONDITIONING_CONDITIONING_CACHE_H__
+#define __SD_CONDITIONING_CONDITIONING_CACHE_H__
+
+#include <algorithm>
+#include <list>
+#include <tuple>
+
+#include "conditioning/conditioner.hpp"
+
+class ConditioningCache {
+    struct Entry {
+        ConditionerParams params;
+        std::vector<sd::Tensor<float>> ref_images;
+        std::vector<MiniMaxH3PresentationItem> references;
+        SDCondition condition;
+
+        Entry(const ConditionerParams& input, const SDCondition& output)
+            : params(input), condition(output) {
+            // Request-owned reference pointers must not outlive the request.
+            if (input.ref_images != nullptr) {
+                ref_images        = *input.ref_images;
+                params.ref_images = &ref_images;
+            }
+            if (input.minimax_h3_references != nullptr) {
+                references                   = *input.minimax_h3_references;
+                params.minimax_h3_references = &references;
+            }
+        }
+
+        Entry(const Entry&)            = delete;
+        Entry& operator=(const Entry&) = delete;
+    };
+
+    size_t capacity_ = 4;
+    std::list<Entry> entries_;
+
+    static bool same_images(const std::vector<sd::Tensor<float>>& a,
+                            const std::vector<sd::Tensor<float>>& b) {
+        return std::equal(a.begin(), a.end(), b.begin(), b.end(),
+                          [](const sd::Tensor<float>& x, const sd::Tensor<float>& y) {
+                              return x.shape() == y.shape() && x.values() == y.values();
+                          });
+    }
+
+    static bool same_params(const ConditionerParams& a, const ConditionerParams& b) {
+        const auto fields = [](const ConditionerParams& p) {
+            const auto& r = p.ref_image_params;
+            return std::tie(p.text, p.clip_skip, p.width, p.height, p.zero_out_masked,
+                            r.pass_to_vlm, r.pass_to_dit, r.ref_index_mode,
+                            r.force_ref_timestep_zero, r.resize_before_vae, r.vae_input_max_pixels,
+                            r.vlm_resize_mode, r.vlm_min_size, r.vlm_max_size, r.resize_vae_to_target);
+        };
+        if (fields(a) != fields(b) ||
+            (a.ref_images == nullptr) != (b.ref_images == nullptr) ||
+            (a.minimax_h3_references == nullptr) != (b.minimax_h3_references == nullptr)) {
+            return false;
+        }
+        if (a.ref_images != nullptr && !same_images(*a.ref_images, *b.ref_images)) {
+            return false;
+        }
+        if (a.minimax_h3_references != nullptr &&
+            !std::equal(a.minimax_h3_references->begin(), a.minimax_h3_references->end(),
+                        b.minimax_h3_references->begin(), b.minimax_h3_references->end(),
+                        [](const MiniMaxH3PresentationItem& x, const MiniMaxH3PresentationItem& y) {
+                            return x.kind == y.kind && x.timestamps == y.timestamps && same_images(x.frames, y.frames);
+                        })) {
+            return false;
+        }
+        return true;
+    }
+
+public:
+    void set_capacity(size_t capacity) {
+        capacity_ = capacity;
+        while (entries_.size() > capacity_) {
+            entries_.pop_back();
+        }
+    }
+
+    void clear() {
+        entries_.clear();
+    }
+
+    SDCondition get(Conditioner& conditioner, int n_threads, const ConditionerParams& params) {
+        if (capacity_ == 0) {
+            return conditioner.get_learned_condition(n_threads, params);
+        }
+        for (auto it = entries_.begin(); it != entries_.end(); ++it) {
+            if (same_params(it->params, params)) {
+                entries_.splice(entries_.begin(), entries_, it);
+                LOG_INFO("conditioning cache hit");
+                return entries_.front().condition;
+            }
+        }
+        auto condition = conditioner.get_learned_condition(n_threads, params);
+        if (!condition.empty()) {
+            if (entries_.size() == capacity_) {
+                entries_.pop_back();
+            }
+            entries_.emplace_front(params, condition);
+            LOG_VERBOSE("conditioning cache stored (%zu/%zu)", entries_.size(), capacity_);
+        }
+        return condition;
+    }
+};
+
+#endif  // __SD_CONDITIONING_CONDITIONING_CACHE_H__

src/core/ggml_runner.cpp

@@ -644,6 +644,10 @@ std::optional<sd::Tensor<float>> GGMLRunner::compute(get_graph_cb_t get_graph,
     std::optional<sd::Tensor<float>> output;
     try {
         output = execute_graph(graph, n_threads, no_return, read_outputs);
+    } catch (const std::bad_alloc&) {
+        last_compute_status_ = GGML_STATUS_ALLOC_FAILED;
+        LOG_ERROR("%s graph allocation failed", get_desc().c_str());
+        return std::nullopt;
     } catch (const std::exception& error) {
         last_compute_status_ = GGML_STATUS_FAILED;
         LOG_ERROR("%s graph execution failed on %s: %s", get_desc().c_str(),
@@ -964,10 +968,16 @@ std::optional<Tensor<float>> GGMLRunner::execute_graph(ggml_cgraph* graph, int n
         }
         LOG_DEBUG("%s executing segment %zu/%zu: %s", get_desc().c_str(),
                   index + 1, plan.segments.size(), segment.group_name.c_str());
-        if (!execute_segment(segment_graph, n_threads) ||
-            !cache_.capture(segment_graph) ||
-            !cut_cache_.capture(graph, segment, get_desc().c_str())) {
-            return fail_segment("execution or output caching");
+        if (!execute_segment(segment_graph, n_threads)) {
+            return fail_segment("execution");
+        }
+        auto cache_status = cache_.capture(segment_graph);
+        if (cache_status == GGML_STATUS_SUCCESS) {
+            cache_status = cut_cache_.capture(graph, segment, get_desc().c_str());
+        }
+        if (cache_status != GGML_STATUS_SUCCESS) {
+            last_compute_status_ = cache_status;
+            return fail_segment("output caching");
         }
         sync_runtime_residency();
         if (last) {

src/core/runner_cache.cpp

@@ -26,10 +26,13 @@ namespace sd {
 
     std::unique_ptr<CachedTensor> CachedTensor::copy(ggml_backend_t backend,
                                                      const std::string& name,
-                                                     ggml_tensor* source) {
+                                                     ggml_tensor* source,
+                                                     ggml_status& status) {
+        status = GGML_STATUS_FAILED;
         if (ggml_graph_cut::tensor_buffer(source) == nullptr) {
             return nullptr;
         }
+        status         = GGML_STATUS_ALLOC_FAILED;
         auto entry     = std::make_unique<CachedTensor>();
         entry->context = ggml_init({2 * ggml_tensor_overhead(), nullptr, true});
         if (entry->context == nullptr) {
@@ -50,6 +53,7 @@ namespace sd {
         } else {
             ggml_backend_tensor_copy(source, entry->tensor);
         }
+        status = GGML_STATUS_SUCCESS;
         return entry;
     }
 
@@ -106,9 +110,9 @@ namespace sd {
         return pending > SIZE_MAX - committed ? SIZE_MAX : committed + pending;
     }
 
-    bool RunnerCache::capture(ggml_cgraph* graph) {
+    ggml_status RunnerCache::capture(ggml_cgraph* graph) {
         if (outputs_.empty()) {
-            return true;
+            return GGML_STATUS_SUCCESS;
         }
         const auto tensors = cache_graph_tensors(graph);
         for (const auto& output : outputs_) {
@@ -116,14 +120,15 @@ namespace sd {
                 continue;
             }
             GGML_ASSERT(ggml_is_contiguous(output.second));
-            auto entry = CachedTensor::copy(backend_, output.first, output.second);
+            ggml_status status;
+            auto entry = CachedTensor::copy(backend_, output.first, output.second, status);
             if (entry == nullptr) {
-                return false;
+                return status;
             }
             pending_[output.first] = std::move(entry);
         }
         ggml_backend_synchronize(backend_);
-        return true;
+        return GGML_STATUS_SUCCESS;
     }
 
     void RunnerCache::graph_end(bool success) {
@@ -180,9 +185,9 @@ namespace sd {
         }
     }
 
-    bool GraphCutTensorCache::capture(ggml_cgraph* graph,
-                                      const ggml_graph_cut::Segment& segment,
-                                      const char* log_desc) {
+    ggml_status GraphCutTensorCache::capture(ggml_cgraph* graph,
+                                             const ggml_graph_cut::Segment& segment,
+                                             const char* log_desc) {
         size_t copied_bytes = 0;
         size_t copied_count = 0;
         for (int index : segment.output_node_indices) {
@@ -191,10 +196,11 @@ namespace sd {
                 !segment.future_cut_names.count(output->name)) {
                 continue;
             }
-            auto entry = CachedTensor::copy(backend_, output->name, ggml_graph_cut::cache_source_tensor(output));
+            ggml_status status;
+            auto entry = CachedTensor::copy(backend_, output->name, ggml_graph_cut::cache_source_tensor(output), status);
             if (entry == nullptr) {
                 LOG_ERROR("%s failed to capture graph cut tensor: %s", log_desc, output->name);
-                return false;
+                return status;
             }
             const size_t size = ggml_backend_buffer_get_size(entry->buffer);
             copied_bytes      = size > SIZE_MAX - copied_bytes ? SIZE_MAX : copied_bytes + size;
@@ -206,6 +212,6 @@ namespace sd {
             LOG_DEBUG("%s graph cut cache added %6.2f MB (%zu tensors)",
                       log_desc, copied_bytes / (1024.f * 1024.f), copied_count);
         }
-        return true;
+        return GGML_STATUS_SUCCESS;
     }
 }

src/core/runner_cache.h

@@ -20,7 +20,8 @@ namespace sd {
         ~CachedTensor();
         static std::unique_ptr<CachedTensor> copy(ggml_backend_t backend,
                                                   const std::string& name,
-                                                  ggml_tensor* source);
+                                                  ggml_tensor* source,
+                                                  ggml_status& status);
     };
     using CachedTensors = std::map<std::string, std::unique_ptr<CachedTensor>>;
 
@@ -41,7 +42,8 @@ namespace sd {
         const std::map<std::string, ggml_tensor*>& outputs() const { return outputs_; }
         size_t pending_bytes(ggml_cgraph* graph) const;
         size_t resident_bytes(ggml_backend_dev_t device) const;
-        bool capture(ggml_cgraph* graph);
+        bool empty() const { return committed_.empty(); }
+        ggml_status capture(ggml_cgraph* graph);
         void graph_end(bool success);
         void clear();
     };
@@ -57,7 +59,7 @@ namespace sd {
         size_t resident_bytes(ggml_backend_dev_t device) const;
         size_t estimate_output_bytes(ggml_cgraph* graph,
                                      const ggml_graph_cut::Segment& segment) const;
-        bool capture(ggml_cgraph* graph, const ggml_graph_cut::Segment& segment, const char* log_desc);
+        ggml_status capture(ggml_cgraph* graph, const ggml_graph_cut::Segment& segment, const char* log_desc);
         void prune(const std::unordered_set<std::string>& keep_names);
         void clear() { tensors_.clear(); }
     };

src/detailer.cpp

@@ -970,6 +970,7 @@ bool adetail_image(adetailer_ctx_t* context,
         generation.pm_params           = {};
         generation.pulid_params        = {};
         generation.hires.enabled       = false;
+        generation.image_preprocess    = {};
         if (params.steps > 0) {
             generation.sample_params.sample_steps        = params.steps;
             generation.sample_params.custom_sigmas       = nullptr;

src/model/diffusion/minimax_h3.hpp

@@ -264,6 +264,9 @@ namespace MiniMaxH3 {
             for (int64_t i = 0; i < num_layers; ++i) {
                 auto block = std::dynamic_pointer_cast<TokenRefinerBlock>(blocks["blocks." + std::to_string(i)]);
                 x          = block->forward(ctx, x);
+                sd::ggml_graph_cut::mark_graph_cut(x,
+                                                   "minimax_h3.token_refiner.blocks." + std::to_string(i),
+                                                   "hidden_states");
             }
             return std::dynamic_pointer_cast<RMSNorm>(blocks["final_norm"])->forward(ctx, x);
         }
@@ -527,7 +530,11 @@ namespace MiniMaxH3 {
             GGML_ASSERT(context->ne[0] == config.text_dim);
             auto condition_proj = std::dynamic_pointer_cast<Linear>(blocks["condition_proj"]);
             auto token_refiner  = std::dynamic_pointer_cast<TokenRefiner>(blocks["token_refiner"]);
-            return token_refiner->forward(ctx, condition_proj->forward(ctx, context));
+            auto projected      = condition_proj->forward(ctx, context);
+            sd::ggml_graph_cut::mark_graph_cut(projected,
+                                               "minimax_h3.condition_proj",
+                                               "hidden_states");
+            return token_refiner->forward(ctx, projected);
         }
 
         ggml_tensor* time_embedding(GGMLRunnerContext* ctx,

src/model/diffusion/model.hpp

@@ -71,6 +71,8 @@ struct AnimaDiffusionExtra {
 
 struct QwenImage21DiffusionExtra {
     const sd::Tensor<int32_t>* image_slots = nullptr;
+    // Nonzero IDs identify immutable prefix inputs within one sampling run.
+    uint64_t prefix_id = 0;
 };
 
 struct WanDiffusionExtra {

src/model/diffusion/qwen_image_2_1.hpp

@@ -121,6 +121,18 @@ namespace Qwen {
         }
     };
 
+    struct QwenImage21PrefixCache {
+        enum class Mode {
+            NONE,
+            STORE,
+            REUSE
+        };
+        Mode mode = Mode::NONE;
+        std::string name;
+        std::string cut_group;
+        int64_t prefix_length = 0;
+    };
+
     class QwenImage21ZeroCenterRMSNorm : public RMSNorm {
     public:
         using RMSNorm::RMSNorm;
@@ -160,27 +172,49 @@ namespace Qwen {
             }
         }
 
-        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, ggml_tensor* pe, const std::vector<QwenImage21Segment>& segments, const std::vector<ggml_tensor*>& masks) {
+        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, ggml_tensor* pe, const std::vector<QwenImage21Segment>& segments, const std::vector<ggml_tensor*>& masks, const QwenImage21PrefixCache& cache) {
             int64_t heads = x->ne[0] / dim_head;
             auto project  = [&](const char* name) {
                 auto h = std::dynamic_pointer_cast<Linear>(blocks[name])->forward(ctx, x);
                 return ggml_reshape_4d(ctx->ggml_ctx, h, dim_head, heads, x->ne[1], x->ne[2]);
             };
-            auto q              = project("to_q");
-            auto k              = project("to_k");
-            auto v              = project("to_v");
-            q                   = std::dynamic_pointer_cast<RMSNorm>(blocks["norm_q"])->forward(ctx, q);
-            k                   = std::dynamic_pointer_cast<RMSNorm>(blocks["norm_k"])->forward(ctx, k);
-            q                   = Rope::apply_rope(ctx->ggml_ctx, q, pe);
-            k                   = Rope::apply_rope(ctx->ggml_ctx, k, pe);
+            auto q = project("to_q");
+            auto k = project("to_k");
+            auto v = project("to_v");
+            q      = std::dynamic_pointer_cast<RMSNorm>(blocks["norm_q"])->forward(ctx, q);
+            k      = std::dynamic_pointer_cast<RMSNorm>(blocks["norm_k"])->forward(ctx, k);
+            q      = Rope::apply_rope(ctx->ggml_ctx, q, pe);
+            k      = Rope::apply_rope(ctx->ggml_ctx, k, pe);
+            if (cache.mode == QwenImage21PrefixCache::Mode::STORE) {
+                auto persist = [&](ggml_tensor* tensor, int axis, const char* name) {
+                    auto part = ggml_ext_slice(ctx->ggml_ctx, tensor, axis, 0, cache.prefix_length);
+                    auto copy = ggml_new_tensor(ctx->ggml_ctx, GGML_TYPE_F32, 4, part->ne);
+                    copy      = ggml_cpy(ctx->ggml_ctx, part, copy);
+                    // Keep the copy in this layer's segment so graph cuts do not
+                    // retain or recompute the full-sequence K/V in the final segment.
+                    sd::ggml_graph_cut::mark_graph_cut(copy, cache.cut_group, name);
+                    ctx->persist_cache_tensor(cache.name + "." + name, copy);
+                };
+                persist(k, 1, "k");
+                persist(v, 2, "v");
+            }
             ggml_tensor* result = nullptr;
-            for (size_t i = 0; i < segments.size(); ++i) {
-                const auto& segment = segments[i];
-                auto sq             = ggml_ext_slice(ctx->ggml_ctx, q, 1, segment.start, segment.end);
-                auto sk             = ggml_ext_slice(ctx->ggml_ctx, k, 1, 0, segment.end);
-                auto sv             = ggml_ext_slice(ctx->ggml_ctx, v, 2, 0, segment.end);
-                auto out            = ggml_ext_attention_ext(ctx, sq, sk, sv, heads, masks[i], true, ctx->flash_attn_enabled);
-                result              = result == nullptr ? out : ggml_concat(ctx->ggml_ctx, result, out, 1);
+            if (cache.mode == QwenImage21PrefixCache::Mode::REUSE) {
+                auto prefix_k = ctx->load_cache_tensor(cache.name + ".k");
+                auto prefix_v = ctx->load_cache_tensor(cache.name + ".v");
+                GGML_ASSERT(prefix_k != nullptr && prefix_v != nullptr);
+                k      = ggml_concat(ctx->ggml_ctx, prefix_k, k, 1);
+                v      = ggml_concat(ctx->ggml_ctx, prefix_v, v, 2);
+                result = ggml_ext_attention_ext(ctx, q, k, v, heads, nullptr, true, ctx->flash_attn_enabled);
+            } else {
+                for (size_t i = 0; i < segments.size(); ++i) {
+                    const auto& segment = segments[i];
+                    auto sq             = ggml_ext_slice(ctx->ggml_ctx, q, 1, segment.start, segment.end);
+                    auto sk             = ggml_ext_slice(ctx->ggml_ctx, k, 1, 0, segment.end);
+                    auto sv             = ggml_ext_slice(ctx->ggml_ctx, v, 2, 0, segment.end);
+                    auto out            = ggml_ext_attention_ext(ctx, sq, sk, sv, heads, masks[i], true, ctx->flash_attn_enabled);
+                    result              = result == nullptr ? out : ggml_concat(ctx->ggml_ctx, result, out, 1);
+                }
             }
             auto to_out = std::dynamic_pointer_cast<Linear>(blocks["to_out.0"]);
             if (sd_backend_is(ctx->backend, "Vulkan") || sd_backend_is(ctx->backend, "ROCm")) {
@@ -219,13 +253,14 @@ namespace Qwen {
             return ggml_concat(ctx, prefix, target, 1);
         }
 
-        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, const std::vector<ggml_tensor*>& modulation, ggml_tensor* pe, const QwenImage21Layout& layout, const std::vector<ggml_tensor*>& masks) {
-            auto h = std::dynamic_pointer_cast<LayerNorm>(blocks["img_norm1"])->forward(ctx, x);
-            h      = modulate(ctx->ggml_ctx, h, modulation[0], layout.prefix_length);
-            h      = std::dynamic_pointer_cast<QwenImage21Attention>(blocks["attn"])->forward(ctx, h, pe, layout.segments, masks);
-            x      = ggml_add(ctx->ggml_ctx, x, modulate(ctx->ggml_ctx, h, modulation[1], layout.prefix_length, true));
-            h      = std::dynamic_pointer_cast<LayerNorm>(blocks["img_norm2"])->forward(ctx, x);
-            h      = modulate(ctx->ggml_ctx, h, modulation[2], layout.prefix_length);
+        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, const std::vector<ggml_tensor*>& modulation, ggml_tensor* pe, const QwenImage21Layout& layout, const std::vector<ggml_tensor*>& masks, const QwenImage21PrefixCache& cache) {
+            const int64_t prefix_length = cache.mode == QwenImage21PrefixCache::Mode::REUSE ? 0 : layout.prefix_length;
+            auto h                      = std::dynamic_pointer_cast<LayerNorm>(blocks["img_norm1"])->forward(ctx, x);
+            h                           = modulate(ctx->ggml_ctx, h, modulation[0], prefix_length);
+            h                           = std::dynamic_pointer_cast<QwenImage21Attention>(blocks["attn"])->forward(ctx, h, pe, layout.segments, masks, cache);
+            x                           = ggml_add(ctx->ggml_ctx, x, modulate(ctx->ggml_ctx, h, modulation[1], prefix_length, true));
+            h                           = std::dynamic_pointer_cast<LayerNorm>(blocks["img_norm2"])->forward(ctx, x);
+            h                           = modulate(ctx->ggml_ctx, h, modulation[2], prefix_length);
             ggml_tensor* gate;
             auto fused = blocks.find("img_mlp.gate_up");
             if (fused != blocks.end()) {
@@ -239,7 +274,7 @@ namespace Qwen {
             }
             h = ggml_mul(ctx->ggml_ctx, h, ggml_silu(ctx->ggml_ctx, gate));
             h = std::dynamic_pointer_cast<Linear>(blocks["img_mlp.out"])->forward(ctx, h);
-            return ggml_add(ctx->ggml_ctx, x, modulate(ctx->ggml_ctx, h, modulation[3], layout.prefix_length, true));
+            return ggml_add(ctx->ggml_ctx, x, modulate(ctx->ggml_ctx, h, modulation[3], prefix_length, true));
         }
     };
 
@@ -261,7 +296,7 @@ namespace Qwen {
             }
         }
 
-        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, ggml_tensor* timestep, ggml_tensor* context, const std::vector<ggml_tensor*>& refs, ggml_tensor* pe, const QwenImage21Layout& layout, const std::vector<ggml_tensor*>& masks) {
+        ggml_tensor* forward(GGMLRunnerContext* ctx, ggml_tensor* x, ggml_tensor* timestep, ggml_tensor* context, const std::vector<ggml_tensor*>& refs, ggml_tensor* pe, const QwenImage21Layout& layout, const std::vector<ggml_tensor*>& masks, const QwenImage21PrefixCache& cache) {
             auto time = ggml_concat(ctx->ggml_ctx, timestep, ggml_ext_zeros_like(ctx->ggml_ctx, timestep), 0);
             // Runtime flow timesteps already use the [0, 1000] scale.
             time               = ggml_ext_timestep_embedding(ctx->ggml_ctx, time, 256, 10000, 1.f);
@@ -269,27 +304,37 @@ namespace Qwen {
             time               = ggml_silu(ctx->ggml_ctx, time);
             auto modulation    = std::dynamic_pointer_cast<Linear>(blocks["modulation.1"])->forward(ctx, time);
             auto mod           = ggml_ext_chunk(ctx->ggml_ctx, modulation, 4, 0);
-            auto text          = std::dynamic_pointer_cast<QwenImage21TextProjection>(blocks["txt_in"])->forward(ctx, context);
             auto img_in        = std::dynamic_pointer_cast<Linear>(blocks["img_in"]);
             ggml_tensor* joint = nullptr;
-            for (const auto& segment : layout.segments) {
-                ggml_tensor* h;
-                if (segment.image_index < 0) {
-                    h = ggml_ext_slice(ctx->ggml_ctx, text, 1, segment.context_start,
-                                       segment.context_start + segment.end - segment.start);
-                } else {
-                    auto image = segment.image_index == static_cast<int>(refs.size()) ? x : refs[segment.image_index];
-                    h          = img_in->forward(ctx, DiT::patchify(ctx->ggml_ctx, image, 1, 1));
+            if (cache.mode == QwenImage21PrefixCache::Mode::REUSE) {
+                joint = img_in->forward(ctx, DiT::patchify(ctx->ggml_ctx, x, 1, 1));
+            } else {
+                auto text = std::dynamic_pointer_cast<QwenImage21TextProjection>(blocks["txt_in"])->forward(ctx, context);
+                for (const auto& segment : layout.segments) {
+                    ggml_tensor* h;
+                    if (segment.image_index < 0) {
+                        h = ggml_ext_slice(ctx->ggml_ctx, text, 1, segment.context_start,
+                                           segment.context_start + segment.end - segment.start);
+                    } else {
+                        auto image = segment.image_index == static_cast<int>(refs.size()) ? x : refs[segment.image_index];
+                        h          = img_in->forward(ctx, DiT::patchify(ctx->ggml_ctx, image, 1, 1));
+                    }
+                    joint = joint == nullptr ? h : ggml_concat(ctx->ggml_ctx, joint, h, 1);
                 }
-                joint = joint == nullptr ? h : ggml_concat(ctx->ggml_ctx, joint, h, 1);
             }
             sd::ggml_graph_cut::mark_graph_cut(joint, "qwen_image_2_1.prelude", "joint");
             for (int i = 0; i < config.num_layers; ++i) {
-                auto block = std::dynamic_pointer_cast<QwenImage21TransformerBlock>(blocks["transformer_blocks." + std::to_string(i)]);
-                joint      = block->forward(ctx, joint, mod, pe, layout, masks);
-                sd::ggml_graph_cut::mark_graph_cut(joint, "qwen_image_2_1.transformer_blocks." + std::to_string(i), "joint");
+                const std::string layer = "transformer_blocks." + std::to_string(i);
+                auto layer_cache        = cache;
+                layer_cache.name        = cache.name + "." + std::to_string(i);
+                layer_cache.cut_group   = "qwen_image_2_1." + layer;
+                auto block              = std::dynamic_pointer_cast<QwenImage21TransformerBlock>(blocks[layer]);
+                joint                   = block->forward(ctx, joint, mod, pe, layout, masks, layer_cache);
+                sd::ggml_graph_cut::mark_graph_cut(joint, layer_cache.cut_group, "joint");
+            }
+            if (cache.mode != QwenImage21PrefixCache::Mode::REUSE) {
+                joint = ggml_ext_slice(ctx->ggml_ctx, joint, 1, layout.prefix_length, joint->ne[1]);
             }
-            joint      = ggml_ext_slice(ctx->ggml_ctx, joint, 1, layout.prefix_length, joint->ne[1]);
             auto scale = std::dynamic_pointer_cast<Linear>(blocks["norm_out.linear"])->forward(ctx, ggml_ext_chunk(ctx->ggml_ctx, time, 2, 1)[0]);
             joint      = std::dynamic_pointer_cast<LayerNorm>(blocks["norm_out.norm"])->forward(ctx, joint);
             joint      = ggml_mul(ctx->ggml_ctx, joint, ggml_scale_bias(ctx->ggml_ctx, scale, 1.f, 1.f));
@@ -303,11 +348,18 @@ namespace Qwen {
         QwenImage21Model model;
         std::vector<float> pe_data;
         std::vector<sd::Tensor<float>> mask_data;
+        bool prefix_cache_enabled  = true;
+        bool prefix_cache_disabled = false;
 
-        QwenImage21Runner(ggml_backend_t backend, const String2TensorStorage& weights, const std::string& prefix, std::shared_ptr<RunnerWeightManager> weight_manager = nullptr)
+        QwenImage21Runner(ggml_backend_t backend, const String2TensorStorage& weights, const std::string& prefix, std::shared_ptr<RunnerWeightManager> weight_manager = nullptr, const char* model_args = nullptr)
             : DiffusionModelRunner(backend, prefix, weight_manager),
               config(QwenImage21Config::detect_from_weights(weights, prefix)),
               model(config) {
+            for (const auto& [key, value] : parse_key_value_args(model_args, "model arg")) {
+                if (key == "qwen_image_2_1_prefix_cache" && !parse_strict_bool(value, prefix_cache_enabled)) {
+                    LOG_WARN("ignoring invalid Qwen Image 2.1 model arg '%s=%s'", key.c_str(), value.c_str());
+                }
+            }
             model.init(params_ctx, weights, prefix);
         }
 
@@ -317,6 +369,22 @@ namespace Qwen {
             model.get_param_tensors(tensors, prefix);
         }
 
+        bool has_prefix_cache(const QwenImage21PrefixCache& cache) {
+            for (int i = 0; i < config.num_layers; ++i) {
+                const auto name = cache.name + "." + std::to_string(i);
+                auto k          = get_cache_tensor_by_name(name + ".k");
+                auto v          = get_cache_tensor_by_name(name + ".v");
+                if (k == nullptr || v == nullptr || k->type != GGML_TYPE_F32 || v->type != GGML_TYPE_F32 ||
+                    k->ne[0] != config.head_dim || k->ne[1] != cache.prefix_length ||
+                    k->ne[2] != config.hidden_size / config.head_dim || k->ne[3] != 1 ||
+                    v->ne[0] != config.head_dim || v->ne[1] != config.hidden_size / config.head_dim ||
+                    v->ne[2] != cache.prefix_length || v->ne[3] != 1) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
         sd::Tensor<float> compute(int n_threads, const DiffusionParams& inputs) override {
             const auto& x       = tensor_or_empty(inputs.x);
             const auto& context = tensor_or_empty(inputs.context);
@@ -345,38 +413,75 @@ namespace Qwen {
                 LOG_ERROR("%s", error.what());
                 return {};
             }
-            pe_data = Rope::embed_nd(layout.positions, 1, 10000.f, config.axes_dim);
-            mask_data.clear();
-            for (const auto& segment : layout.segments) {
-                sd::Tensor<float> mask;
-                if (segment.image_index < 0) {
-                    mask = sd::Tensor<float>::zeros({segment.end, segment.end - segment.start});
-                    for (int64_t q = segment.start; q < segment.end; ++q) {
-                        for (int64_t k = q + 1; k < segment.end; ++k) {
-                            mask[k + segment.end * (q - segment.start)] = -INFINITY;
+            if (!runner_started()) {
+                prefix_cache_disabled = false;
+            }
+            QwenImage21PrefixCache cache;
+            if (prefix_cache_enabled && !prefix_cache_disabled && extra != nullptr && extra->prefix_id != 0 && layout.prefix_length > 0) {
+                cache.name          = "qwen_image_2_1.prefix." + std::to_string(extra->prefix_id);
+                cache.prefix_length = layout.prefix_length;
+                cache.mode          = has_prefix_cache(cache) ? QwenImage21PrefixCache::Mode::REUSE : QwenImage21PrefixCache::Mode::STORE;
+            }
+            auto run = [&](const QwenImage21PrefixCache& active_cache) {
+                const bool cached         = active_cache.mode == QwenImage21PrefixCache::Mode::REUSE;
+                const auto first_position = layout.positions.begin() + (cached ? layout.prefix_length : 0);
+                pe_data                   = Rope::embed_nd(std::vector<std::vector<float>>(first_position, layout.positions.end()), 1, 10000.f, config.axes_dim);
+                mask_data.clear();
+                if (!cached) {
+                    for (const auto& segment : layout.segments) {
+                        sd::Tensor<float> mask;
+                        if (segment.image_index < 0) {
+                            mask = sd::Tensor<float>::zeros({segment.end, segment.end - segment.start});
+                            for (int64_t q = segment.start; q < segment.end; ++q) {
+                                for (int64_t k = q + 1; k < segment.end; ++k) {
+                                    mask[k + segment.end * (q - segment.start)] = -INFINITY;
+                                }
+                            }
                         }
+                        mask_data.push_back(std::move(mask));
                     }
                 }
-                mask_data.push_back(std::move(mask));
-            }
-            auto build = [&]() {
-                auto graph = new_graph_custom(QWEN_IMAGE_GRAPH_SIZE * 2);
-                auto pe    = ggml_new_tensor_4d(compute_ctx, GGML_TYPE_F32, 2, 2, config.head_dim / 2, layout.positions.size());
-                set_backend_tensor_data(pe, pe_data.data());
-                std::vector<ggml_tensor*> masks, ref_inputs;
-                for (const auto& mask : mask_data) {
-                    masks.push_back(mask.empty() ? nullptr : make_input(mask));
-                }
-                for (const auto& ref : refs) {
-                    ref_inputs.push_back(make_input(ref));
-                }
-                auto ctx = get_context();
-                auto out = model.forward(&ctx, make_input(x), make_input(*inputs.timesteps), make_input(context),
-                                         ref_inputs, pe, layout, masks);
-                ggml_build_forward_expand(graph, out);
-                return graph;
+                auto build = [&]() {
+                    auto graph = new_graph_custom(QWEN_IMAGE_GRAPH_SIZE * 2);
+                    auto pe    = ggml_new_tensor_4d(compute_ctx, GGML_TYPE_F32, 2, 2, config.head_dim / 2,
+                                                    layout.positions.size() - (cached ? layout.prefix_length : 0));
+                    set_backend_tensor_data(pe, pe_data.data());
+                    std::vector<ggml_tensor*> masks, ref_inputs;
+                    for (const auto& mask : mask_data) {
+                        masks.push_back(mask.empty() ? nullptr : make_input(mask));
+                    }
+                    if (!cached) {
+                        for (const auto& ref : refs) {
+                            ref_inputs.push_back(make_input(ref));
+                        }
+                    }
+                    auto ctx = get_context();
+                    auto out = model.forward(&ctx, make_input(x), make_input(*inputs.timesteps), cached ? nullptr : make_input(context),
+                                             ref_inputs, pe, layout, masks, active_cache);
+                    ggml_build_forward_expand(graph, out);
+                    return graph;
+                };
+                return restore_trailing_singleton_dims(GGMLRunner::compute(build, n_threads, false), x.dim());
             };
-            return restore_trailing_singleton_dims(GGMLRunner::compute(build, n_threads, false), x.dim());
+            auto result = run(cache);
+            if (result.empty() && last_compute_status() == GGML_STATUS_ALLOC_FAILED &&
+                (cache.mode != QwenImage21PrefixCache::Mode::NONE || !cache_.empty())) {
+                // The failed graph has ended before persistent inputs are released.
+                free_cache_ctx_and_buffer();
+                prefix_cache_disabled = true;
+                LOG_WARN("Qwen Image 2.1: insufficient memory for prefix caching; retrying without it for this sampling run");
+                return run(QwenImage21PrefixCache{});
+            }
+            if (!result.empty() && cache.mode == QwenImage21PrefixCache::Mode::STORE) {
+                if (!has_prefix_cache(cache)) {
+                    free_cache_ctx_and_buffer();
+                    prefix_cache_disabled = true;
+                    LOG_WARN("Qwen Image 2.1: incomplete prefix cache; disabling it for this sampling run");
+                } else {
+                    LOG_DEBUG("Qwen Image 2.1: cached prefix %" PRIu64 " (%" PRId64 " tokens)", extra->prefix_id, layout.prefix_length);
+                }
+            }
+            return result;
         }
     };
 }

src/model/vae/wan_vae.hpp

@@ -82,6 +82,20 @@ namespace WAN {
             }
 
             x = ggml_ext_pad_ext(ctx->ggml_ctx, ctx->backend, x, lp0, rp0, lp1, rp1, lp2, rp2, 0, 0, ctx->circular_x_enabled, ctx->circular_y_enabled);
+            if (w->ne[2] == 1 && x->ne[2] == 1 && x->ne[3] == in_channels) {
+                // One frame through a one-frame-deep kernel is a 2D conv; backends without
+                // im2col_3d (Metal) otherwise fall back to a much slower direct conv_3d.
+                if (!ggml_is_contiguous(x)) {
+                    x = ggml_cont(ctx->ggml_ctx, x);
+                }
+                ggml_tensor* x2 = ggml_reshape_4d(ctx->ggml_ctx, x, x->ne[0], x->ne[1], in_channels, 1);
+                ggml_tensor* w2 = ggml_reshape_4d(ctx->ggml_ctx, w, w->ne[0], w->ne[1], in_channels, out_channels);
+                x2              = ggml_ext_conv_2d(ctx->ggml_ctx, x2, w2, b,
+                                                   std::get<2>(stride), std::get<1>(stride), 0, 0,
+                                                   std::get<2>(dilation), std::get<1>(dilation),
+                                                   ctx->conv2d_direct_enabled);
+                return ggml_reshape_4d(ctx->ggml_ctx, x2, x2->ne[0], x2->ne[1], 1, out_channels);
+            }
             return ggml_ext_conv_3d(ctx->ggml_ctx, ctx->backend, x, w, b, in_channels,
                                     std::get<2>(stride), std::get<1>(stride), std::get<0>(stride),
                                     0, 0, 0,

src/pipeline/diffusion_engine.cpp

@@ -7,6 +7,7 @@
 #include <list>
 #include <mutex>
 #include <set>
+#include <tuple>
 #include <type_traits>
 #include <unordered_set>
 #include <utility>
@@ -29,6 +30,7 @@
 #include "stable-diffusion.h"
 
 #include "conditioning/conditioner.hpp"
+#include "conditioning/conditioning_cache.h"
 #include "core/backend_fit.h"
 #include "extensions/generation_extension.h"
 #include "model/adapter/ip_adapter.hpp"
@@ -135,6 +137,7 @@ static_assert(std::atomic<sd_cancel_mode_t>::is_always_lock_free,
 
 StableDiffusionGGML::StableDiffusionGGML()
     : rng(std::make_shared<PhiloxRNG>()),
+      conditioning_cache_(std::make_unique<ConditioningCache>()),
       denoiser(std::make_shared<CompVisDenoiser>()) {}
 
 StableDiffusionGGML::~StableDiffusionGGML() = default;
@@ -204,6 +207,8 @@ void StableDiffusionGGML::end_runners() {
 }
 
 bool StableDiffusionGGML::reset_runners(const RunnerGroups& groups) {
+    conditioning_cache_->clear();
+    conditioning_loras_.clear();
     end_runners();
     clear_lora_adapters();
     runtime_lora_models.clear();
@@ -915,6 +920,11 @@ bool StableDiffusionGGML::init(const sd_ctx_params_t* sd_ctx_params) {
             return false;
         }
     }
+    if (sd_ctx_params->conditioning_cache_size < 0) {
+        LOG_ERROR("conditioning_cache_size must be non-negative");
+        return false;
+    }
+    conditioning_cache_->set_capacity(static_cast<size_t>(sd_ctx_params->conditioning_cache_size));
     auto configuration = std::make_unique<ModelConfig>(*sd_ctx_params);
     n_threads          = sd_ctx_params->n_threads;
     tensor_executor    = std::make_unique<sd::ParallelExecutor>(n_threads > 0 ? n_threads : sd_get_num_physical_cores());
@@ -1765,8 +1775,19 @@ bool StableDiffusionGGML::apply_loras(const sd_lora_t* loras, uint32_t lora_coun
     int64_t t0 = ggml_time_ms();
     end_runners();
     clear_lora_adapters();
-    if (!model_manager->prepare_lora_sources(all_loras))
+    if (!model_manager->prepare_lora_sources(all_loras)) {
+        conditioning_cache_->clear();
         return false;
+    }
+    if (!std::equal(all_loras.begin(), all_loras.end(),
+                    conditioning_loras_.begin(), conditioning_loras_.end(),
+                    [](const ModelManager::LoraSpec& a, const ModelManager::LoraSpec& b) {
+                        return a.file_id == b.file_id && a.file_revision == b.file_revision &&
+                               a.multiplier == b.multiplier && a.is_high_noise == b.is_high_noise &&
+                               a.tensor_name_prefix_filter == b.tensor_name_prefix_filter;
+                    })) {
+        conditioning_cache_->clear();
+    }
     runtime_lora_models.erase(std::remove_if(runtime_lora_models.begin(), runtime_lora_models.end(), [&](const RuntimeLora& entry) {
                                   return std::none_of(all_loras.begin(), all_loras.end(), [&](const ModelManager::LoraSpec& spec) {
                                       return entry.matches(spec);
@@ -1776,6 +1797,7 @@ bool StableDiffusionGGML::apply_loras(const sd_lora_t* loras, uint32_t lora_coun
     const bool success = apply_lora_immediately ? apply_loras_immediately(all_loras)
                                                 : apply_loras_at_runtime(all_loras);
     if (!success) {
+        conditioning_cache_->clear();
         clear_lora_adapters();
         runtime_lora_models.clear();
         return false;
@@ -1785,9 +1807,14 @@ bool StableDiffusionGGML::apply_loras(const sd_lora_t* loras, uint32_t lora_coun
     if (!all_loras.empty()) {
         LOG_INFO("apply_loras completed, taking %.2fs", (t1 - t0) * 1.0f / 1000);
     }
+    conditioning_loras_ = std::move(all_loras);
     return true;
 }
 
+SDCondition StableDiffusionGGML::get_learned_condition(const ConditionerParams& params) {
+    return conditioning_cache_->get(*cond_stage_model, n_threads, params);
+}
+
 void StableDiffusionGGML::reset_generation_extensions() {
     for (auto& extension : generation_extensions) {
         extension->reset_runtime_condition();
@@ -1972,6 +1999,8 @@ void StableDiffusionGGML::preview_image(int step,
         int patch_sz                     = 1;
         const float(*latent_rgb_proj)[3] = nullptr;
         float* latent_rgb_bias           = nullptr;
+        const float* latent_alpha_proj   = nullptr;
+        float latent_alpha_bias          = 1.f;
 
         if (channels == 128) {
             if (sd_version_uses_flux2_vae(version)) {
@@ -1985,6 +2014,16 @@ void StableDiffusionGGML::preview_image(int step,
                 LOG_WARN("No latent to RGB projection known for this model");
                 return;
             }
+        } else if (channels == 64) {
+            if (version == VERSION_QWEN_IMAGE_2_1) {
+                latent_rgb_proj   = qwen21_latent_rgb_proj;
+                latent_rgb_bias   = qwen21_latent_rgb_bias;
+                latent_alpha_proj = qwen21_latent_alpha_proj;
+                latent_alpha_bias = qwen21_latent_alpha_bias;
+            } else {
+                LOG_WARN("No latent to RGB projection known for this model");
+                return;
+            }
         } else if (channels == 48) {
             if (sd_version_is_wan(version)) {
                 latent_rgb_proj = wan_22_latent_rgb_proj;
@@ -2035,13 +2074,14 @@ void StableDiffusionGGML::preview_image(int step,
         uint32_t img_width  = static_cast<uint32_t>(_latents.shape()[0]) * patch_sz;
         uint32_t img_height = static_cast<uint32_t>(_latents.shape()[1]) * patch_sz;
 
-        uint8_t* data = (uint8_t*)malloc(frames * img_width * img_height * 3 * sizeof(uint8_t));
+        uint32_t img_channels = latent_alpha_proj != nullptr ? 4 : 3;
+        uint8_t* data         = (uint8_t*)malloc(frames * img_width * img_height * img_channels * sizeof(uint8_t));
         GGML_ASSERT(data != nullptr);
-        preview_latent_video(data, _latents, latent_rgb_proj, latent_rgb_bias, patch_sz);
+        preview_latent_video(data, _latents, latent_rgb_proj, latent_rgb_bias, patch_sz, latent_alpha_proj, latent_alpha_bias);
         sd_image_t* images = (sd_image_t*)malloc(frames * sizeof(sd_image_t));
         GGML_ASSERT(images != nullptr);
         for (uint32_t i = 0; i < frames; i++) {
-            images[i] = {img_width, img_height, 3, data + i * img_width * img_height * 3};
+            images[i] = {img_width, img_height, img_channels, data + i * img_width * img_height * img_channels};
         }
         step_callback(step, frames, images, is_noisy, step_callback_data);
         free(data);
@@ -2216,6 +2256,15 @@ sd::Tensor<float> StableDiffusionGGML::sample(const std::shared_ptr<DiffusionMod
     };
     RunnerEndOnExit sample_diffusion_runner_end{work_diffusion_model.get()};
 
+    // These inputs are immutable for this sampling run. Extensions may replace or
+    // modify them per step, so those paths need an explicit stability contract first.
+    const bool cache_qwen_prefix = version == VERSION_QWEN_IMAGE_2_1 &&
+                                   std::none_of(generation_extensions.begin(), generation_extensions.end(),
+                                                [](const auto& extension) { return extension->is_enabled(); });
+    using QwenPrefixInputs = std::tuple<const sd::Tensor<float>*, const sd::Tensor<int32_t>*,
+                                        const std::vector<sd::Tensor<float>>*>;
+    std::vector<QwenPrefixInputs> qwen_prefix_inputs;
+
     RunnerEndOnExit sample_control_runner_end{!control_image.empty() && control_net != nullptr ? control_net.get() : nullptr};
 
     const bool apply_denoise_mask = !denoise_mask.empty() &&
@@ -2485,6 +2534,18 @@ sd::Tensor<float> StableDiffusionGGML::sample(const std::shared_ptr<DiffusionMod
                 extension->before_diffusion(diffusion_params, step);
             }
 
+            if (cache_qwen_prefix) {
+                auto* extra = std::get_if<QwenImage21DiffusionExtra>(&diffusion_params.extra);
+                if (extra != nullptr) {
+                    auto key         = std::make_tuple(diffusion_params.context, extra->image_slots,
+                                               diffusion_params.ref_image_params.pass_to_dit ? diffusion_params.ref_latents : nullptr);
+                    auto entry       = std::find(qwen_prefix_inputs.begin(), qwen_prefix_inputs.end(), key);
+                    extra->prefix_id = static_cast<uint64_t>(entry - qwen_prefix_inputs.begin()) + 1;
+                    if (entry == qwen_prefix_inputs.end()) {
+                        qwen_prefix_inputs.push_back(key);
+                    }
+                }
+            }
             auto output_opt = work_diffusion_model->compute(n_threads, diffusion_params);
             if (output_opt.empty()) {
                 LOG_ERROR("diffusion model compute failed");

src/pipeline/diffusion_engine.h

@@ -26,6 +26,7 @@ class RNG;
 struct Denoiser;
 struct LoraModel;
 struct ConditionerParams;
+class ConditioningCache;
 struct SDCondition;
 struct RefImageParams;
 namespace Wav2Vec2 {
@@ -178,6 +179,8 @@ public:
     std::recursive_mutex execution_mutex;
     std::unique_ptr<ModelConfig> config_;
     RunnerState runner_state_;
+    std::unique_ptr<ConditioningCache> conditioning_cache_;
+    std::vector<ModelManager::LoraSpec> conditioning_loras_;
     bool executing_ = false;
 
     std::shared_ptr<Denoiser> denoiser;
@@ -361,6 +364,8 @@ public:
 
     bool apply_loras(const sd_lora_t* loras, uint32_t lora_count);
 
+    SDCondition get_learned_condition(const ConditionerParams& params);
+
     void reset_generation_extensions();
 
     void prepare_generation_extensions(const sd_pm_params_t& pm_params,

src/pipeline/image.cpp

@@ -10,6 +10,7 @@
 #include "model/vae/vae.hpp"
 #include "request.h"
 #include "runtime/denoiser.hpp"
+#include "runtime/image_preprocess.h"
 #include "upscaler.h"
 
 namespace sd::pipeline {
@@ -440,8 +441,7 @@ namespace sd::pipeline {
         sd->compute_ip_adapter_tokens(sd_img_gen_params->ip_adapter_image, sd_img_gen_params->ip_adapter_strength);
         int64_t prepare_start_ms         = ggml_time_ms();
         condition_params.zero_out_masked = false;
-        auto cond                        = sd->cond_stage_model->get_learned_condition(sd->n_threads,
-                                                                                       condition_params);
+        auto cond                        = sd->get_learned_condition(condition_params);
         if (cond.empty()) {
             LOG_ERROR("failed to encode prompt");
             return std::nullopt;
@@ -479,8 +479,7 @@ namespace sd::pipeline {
                     // LLaDA-Image CFG keeps the source latent but drops its SigVQ features.
                     condition_params.ref_images = nullptr;
                 }
-                uncond = sd->cond_stage_model->get_learned_condition(sd->n_threads,
-                                                                     condition_params);
+                uncond = sd->get_learned_condition(condition_params);
                 if (uncond.empty()) {
                     LOG_ERROR("failed to encode negative prompt");
                     return std::nullopt;
@@ -508,8 +507,7 @@ namespace sd::pipeline {
                 if (use_ref_latent_img_cfg) {
                     condition_params.ref_images = &empty_ref_images;
                 }
-                img_uncond = sd->cond_stage_model->get_learned_condition(sd->n_threads,
-                                                                         condition_params);
+                img_uncond = sd->get_learned_condition(condition_params);
                 if (img_uncond.empty()) {
                     LOG_ERROR("failed to encode image guidance prompt");
                     return std::nullopt;
@@ -800,6 +798,12 @@ namespace sd::pipeline {
         int64_t t0            = ggml_time_ms();
         sd->vae_tiling_params = sd_img_gen_params->vae_tiling_params;
         GenerationRequest request(sd, sd_img_gen_params);
+        sd::ImagePreprocessor preprocessing(sd_img_gen_params->image_preprocess.rules);
+        sd_img_gen_params_t processed_params = *sd_img_gen_params;
+        if (!preprocessing.prepare_inputs(processed_params, request.width, request.height))
+            return false;
+        sd_img_gen_params = &processed_params;
+        request.pm_params = processed_params.pm_params;
         LOG_INFO("generate_image %dx%d", request.width, request.height);
 
         sd->rng->manual_seed(request.seed);

src/pipeline/model_builders.cpp

@@ -291,7 +291,8 @@ namespace sd::model_builders {
                 result.diffusion = std::make_shared<Qwen::QwenImage21Runner>(ctx.backends.runtime_backend(SDBackendModule::DIFFUSION),
                                                                              tensor_storage_map,
                                                                              "model.diffusion_model",
-                                                                             weight_manager);
+                                                                             weight_manager,
+                                                                             sd_ctx_params->model_args);
             } else {
                 result.diffusion = std::make_shared<Qwen::QwenImageRunner>(ctx.backends.runtime_backend(SDBackendModule::DIFFUSION),
                                                                            tensor_storage_map,

src/pipeline/video.cpp

@@ -15,6 +15,7 @@
 #include "model/vae/vae.hpp"
 #include "request.h"
 #include "runtime/denoiser.hpp"
+#include "runtime/image_preprocess.h"
 
 namespace sd::pipeline {
 
@@ -1161,8 +1162,7 @@ namespace sd::pipeline {
         }
 
         int64_t prepare_start_ms = ggml_time_ms();
-        embeds.cond              = sd->cond_stage_model->get_learned_condition(sd->n_threads,
-                                                                               condition_params);
+        embeds.cond              = sd->get_learned_condition(condition_params);
         if (embeds.cond.empty()) {
             LOG_ERROR("failed to encode video prompt");
             return std::nullopt;
@@ -1187,8 +1187,7 @@ namespace sd::pipeline {
         }
         if (request.use_uncond) {
             condition_params.text = request.negative_prompt;
-            embeds.uncond         = sd->cond_stage_model->get_learned_condition(sd->n_threads,
-                                                                                condition_params);
+            embeds.uncond         = sd->get_learned_condition(condition_params);
             if (embeds.uncond.empty()) {
                 LOG_ERROR("failed to encode negative video prompt");
                 return std::nullopt;
@@ -1526,6 +1525,7 @@ namespace sd::pipeline {
         img_gen_params.qwen_image_layers = 0;
         img_gen_params.circular_x        = sd_vid_gen_params->circular_x;
         img_gen_params.circular_y        = sd_vid_gen_params->circular_y;
+        img_gen_params.image_preprocess  = sd_vid_gen_params->image_preprocess;
 
         sd->animatediff_num_frames = n_frames;
         bool ok                    = generate_image(sd, &img_gen_params, frames_out, num_frames_out);
@@ -1556,6 +1556,11 @@ namespace sd::pipeline {
         sd->vae_tiling_params = sd_vid_gen_params->vae_tiling_params;
         sd->apply_circular_axes(sd_vid_gen_params->circular_x, sd_vid_gen_params->circular_y);
         GenerationRequest request(sd, sd_vid_gen_params);
+        sd::ImagePreprocessor preprocessing(sd_vid_gen_params->image_preprocess.rules);
+        sd_vid_gen_params_t processed_params = *sd_vid_gen_params;
+        if (!preprocessing.prepare_inputs(processed_params, request.width, request.height))
+            return false;
+        sd_vid_gen_params = &processed_params;
         if (fps_out != nullptr) {
             *fps_out = request.fps;
         }

src/runtime/image_preprocess.cpp

@@ -0,0 +1,447 @@
+#include "image_preprocess.h"
+#include "core/util.h"
+
+#include <climits>
+#include <set>
+
+namespace sd {
+
+    static constexpr std::pair<const char*, ImageTarget> image_targets[] = {
+        {"init", ImageTarget::Init},
+        {"end", ImageTarget::End},
+        {"mask", ImageTarget::Mask},
+        {"control", ImageTarget::Control},
+        {"ref", ImageTarget::Ref},
+        {"ip-adapter", ImageTarget::IPAdapter},
+        {"id", ImageTarget::ID},
+        {"control-frame", ImageTarget::ControlFrame},
+    };
+
+    static constexpr std::pair<const char*, ImageResizeMode> image_resize_modes[] = {
+        {"auto", ImageResizeMode::Auto},
+        {"none", ImageResizeMode::None},
+        {"stretch", ImageResizeMode::Stretch},
+        {"crop", ImageResizeMode::Crop},
+        {"crop-resize", ImageResizeMode::CropResize},
+        {"fit-pad", ImageResizeMode::FitPad},
+    };
+
+    template <typename T, size_t N>
+    static bool parse_enum(const std::string& text, const std::pair<const char*, T> (&names)[N], T& value) {
+        for (const auto& entry : names) {
+            if (text == entry.first) {
+                value = entry.second;
+                return true;
+            }
+        }
+        return false;
+    }
+
+    template <typename T, size_t N>
+    static const char* enum_name(T value, const std::pair<const char*, T> (&names)[N]) {
+        for (const auto& entry : names) {
+            if (value == entry.second)
+                return entry.first;
+        }
+        return "unknown";
+    }
+
+    template <typename T>
+    static bool one_of(T value, std::initializer_list<T> choices) {
+        return std::find(choices.begin(), choices.end(), value) != choices.end();
+    }
+
+    static bool one_of(const std::string& value, std::initializer_list<const char*> choices) {
+        for (const char* choice : choices) {
+            if (value == choice)
+                return true;
+        }
+        return false;
+    }
+
+    static ImageResizeMode resolve_mode(const std::map<std::string, std::string>& options, ImageResizeMode default_mode) {
+        auto it              = options.find("mode");
+        ImageResizeMode mode = ImageResizeMode::Auto;
+        if (it != options.end())
+            parse_enum(it->second, image_resize_modes, mode);
+        if (mode != ImageResizeMode::Auto)
+            return mode;
+        return options.count("width") && default_mode == ImageResizeMode::None ? ImageResizeMode::Stretch : default_mode;
+    }
+
+    bool ImagePreprocessor::fail(const std::string& message) const {
+        LOG_ERROR("image preprocessing: %s", message.c_str());
+        valid_ = false;
+        return false;
+    }
+
+    ImagePreprocessor::ImagePreprocessor(const char* text) {
+        if (text == nullptr || trim(text).empty())
+            return;
+        for (const auto& part : split_string(text, ';')) {
+            ImagePreprocessRule rule;
+            std::set<std::string> keys;
+            if (trim(part).empty()) {
+                fail("empty rule");
+                return;
+            }
+            for (const auto& entry : split_string(part, ',')) {
+                size_t equal = entry.find('=');
+                if (equal == std::string::npos) {
+                    fail("expected key=value: " + entry);
+                    return;
+                }
+                std::string key   = trim(entry.substr(0, equal));
+                std::string value = trim(entry.substr(equal + 1));
+                bool ok           = !value.empty() && keys.insert(key).second;
+                int number        = 0;
+                if (key == "target") {
+                    ok &= parse_enum(value, image_targets, rule.target);
+                } else if (key == "index") {
+                    ok &= parse_strict_int(value, rule.index) && rule.index >= 0;
+                } else {
+                    if (key == "mode") {
+                        ImageResizeMode mode;
+                        ok &= parse_enum(value, image_resize_modes, mode);
+                    } else if (key == "filter") {
+                        ok &= one_of(value, {"auto", "nearest", "nearest-exact", "bilinear", "bicubic", "lanczos"});
+                    } else if (key == "antialias") {
+                        ok &= one_of(value, {"auto", "true", "false"});
+                    } else if (key == "canny") {
+                        ok &= one_of(value, {"true", "false"});
+                    } else if (key == "anchor") {
+                        ok &= one_of(value, {"center", "top", "bottom", "left", "right"});
+                    } else if (key == "width" || key == "height") {
+                        ok &= parse_strict_int(value, number) && number > 0;
+                    } else if (key == "pad_color") {
+                        ok &= value.size() == 7 || value.size() == 9;
+                        ok &= !value.empty() && value[0] == '#';
+                        for (size_t i = 1; i < value.size(); ++i)
+                            ok &= std::isxdigit(static_cast<unsigned char>(value[i])) != 0;
+                    } else {
+                        ok = false;
+                    }
+                    rule.options[key] = value;
+                }
+                if (!ok) {
+                    fail("invalid or duplicate option: " + entry);
+                    return;
+                }
+            }
+            if (!keys.count("target") || rule.options.empty() ||
+                rule.options.count("width") != rule.options.count("height") ||
+                (rule.index >= 0 && !one_of(rule.target, {ImageTarget::Ref, ImageTarget::ID, ImageTarget::ControlFrame}))) {
+                fail("invalid target, index, or incomplete dimensions: " + part);
+                return;
+            }
+            rules_.push_back(std::move(rule));
+        }
+        for (const auto& rule : rules_) {
+            const auto options = resolve_options(rule.target, std::max(0, rule.index));
+            if (options.count("antialias") && options.at("antialias") == "true" && options.count("filter") &&
+                one_of(options.at("filter"), {"nearest", "nearest-exact"})) {
+                fail("antialias requires bilinear, bicubic, or lanczos");
+                return;
+            }
+        }
+    }
+
+    std::map<std::string, std::string> ImagePreprocessor::resolve_options(ImageTarget target, int index) const {
+        std::map<std::string, std::string> options;
+        for (int specificity = 0; specificity < 2; ++specificity) {
+            for (const auto& rule : rules_) {
+                if (rule.target == target &&
+                    rule.index == (specificity == 0 ? -1 : index)) {
+                    for (const auto& entry : rule.options)
+                        options[entry.first] = entry.second;
+                }
+            }
+        }
+        return options;
+    }
+
+    bool ImagePreprocessor::validate_inputs(const sd_img_gen_params_t& params) const {
+        const std::map<ImageTarget, int> counts = {
+            {ImageTarget::Init, params.init_image.data != nullptr},
+            {ImageTarget::Mask, params.mask_image.data != nullptr},
+            {ImageTarget::Control, params.control_image.data != nullptr},
+            {ImageTarget::IPAdapter, params.ip_adapter_image.data != nullptr},
+            {ImageTarget::Ref, params.ref_images != nullptr ? params.ref_images_count : 0},
+            {ImageTarget::ID, params.pm_params.id_images != nullptr ? params.pm_params.id_images_count : 0},
+        };
+        for (const auto& rule : rules_) {
+            auto it   = counts.find(rule.target);
+            int count = it == counts.end() ? 0 : it->second;
+            if (count <= 0 || rule.index >= count) {
+                return fail(std::string("rule targets an unavailable image: ") + enum_name(rule.target, image_targets));
+            }
+        }
+        return valid_;
+    }
+
+    bool ImagePreprocessor::validate_inputs(const sd_vid_gen_params_t& params) const {
+        const std::map<ImageTarget, int> counts = {
+            {ImageTarget::Init, params.init_image.data != nullptr},
+            {ImageTarget::End, params.end_image.data != nullptr},
+            {ImageTarget::Ref, params.ref_images != nullptr ? params.ref_images_count : 0},
+            {ImageTarget::ControlFrame, params.control_frames != nullptr ? params.control_frames_size : 0},
+        };
+        for (const auto& rule : rules_) {
+            auto it   = counts.find(rule.target);
+            int count = it == counts.end() ? 0 : it->second;
+            if (count <= 0 || rule.index >= count)
+                return fail(std::string("rule targets an unavailable video input: ") + enum_name(rule.target, image_targets));
+        }
+        return valid_;
+    }
+
+    static int anchor_offset(int remaining, const std::string& anchor, bool horizontal) {
+        if (anchor == (horizontal ? "left" : "top"))
+            return 0;
+        if (anchor == (horizontal ? "right" : "bottom"))
+            return remaining;
+        return remaining / 2;
+    }
+
+    Tensor<float> ImagePreprocessor::apply_transform(const Tensor<float>& image, const std::map<std::string, std::string>& options, ImageTransform p, const std::string& label, ops::InterpolateMode default_filter) const {
+        auto value = [&](const char* key, const char* fallback) {
+            auto it = options.find(key);
+            return it == options.end() ? std::string(fallback) : it->second;
+        };
+        std::string filter        = value("filter", "auto");
+        ops::InterpolateMode mode = default_filter;
+        if (filter == "nearest")
+            mode = ops::InterpolateMode::Nearest;
+        if (filter == "nearest-exact")
+            mode = ops::InterpolateMode::NearestExact;
+        if (filter == "bilinear")
+            mode = ops::InterpolateMode::Bilinear;
+        if (filter == "bicubic")
+            mode = ops::InterpolateMode::Bicubic;
+        if (filter == "lanczos")
+            mode = ops::InterpolateMode::Lanczos;
+        bool filtered  = ops::is_2d_filter_interpolate_mode(mode);
+        bool antialias = value("antialias", "auto") == "true" ||
+                         (value("antialias", "auto") == "auto" && filtered &&
+                          (p.resize_width < p.crop_width || p.resize_height < p.crop_height));
+        if (antialias && !filtered) {
+            fail(label + ": antialias requires bilinear, bicubic, or lanczos");
+            return {};
+        }
+        auto cropped = ops::slice(ops::slice(image, 0, p.x, p.x + p.crop_width), 1, p.y, p.y + p.crop_height);
+        int channels = static_cast<int>(image.shape()[2]);
+        bool resize  = p.resize_width != p.crop_width || p.resize_height != p.crop_height;
+        if (resize && channels == 4 && filtered) {
+            for (int64_t i = 0, pixels = cropped.shape()[0] * cropped.shape()[1]; i < pixels; ++i) {
+                for (int c = 0; c < 3; ++c)
+                    cropped[i + c * pixels] *= cropped[i + 3 * pixels];
+            }
+        }
+        auto resized = ops::interpolate(cropped, {p.resize_width, p.resize_height, channels, 1}, mode, false, antialias);
+        if (resize && channels == 4 && filtered) {
+            for (int64_t i = 0, pixels = resized.shape()[0] * resized.shape()[1]; i < pixels; ++i) {
+                float alpha = std::clamp(resized[i + 3 * pixels], 0.f, 1.f);
+                for (int c = 0; c < 3; ++c)
+                    resized[i + c * pixels] = alpha > 1e-6f ? resized[i + c * pixels] / alpha : 0.f;
+            }
+        }
+        resized = ops::clamp(resized, 0.f, 1.f);
+        Tensor<float> output({p.width, p.height, channels, 1});
+        std::string color = value("pad_color", "#000000ff");
+        if (color.size() == 7)
+            color += "ff";
+        uint8_t rgba[4];
+        for (int c = 0; c < 4; ++c)
+            rgba[c] = static_cast<uint8_t>(std::strtoul(color.substr(1 + c * 2, 2).c_str(), nullptr, 16));
+        for (int c = 0; c < channels; ++c) {
+            float fill = rgba[channels == 1 ? 0 : c] / 255.f;
+            for (int y = 0; y < p.height; ++y) {
+                for (int x = 0; x < p.width; ++x) {
+                    output.index(x, y, c, 0) = x >= p.pad_x && x < p.pad_x + p.resize_width && y >= p.pad_y && y < p.pad_y + p.resize_height
+                                                   ? resized.index(x - p.pad_x, y - p.pad_y, c, 0)
+                                                   : fill;
+                }
+            }
+        }
+        LOG_INFO("preprocess %s: %dx%d crop=(%d,%d,%d,%d) resize=%dx%d pad=(%d,%d) output=%dx%d filter=%s(%d) antialias=%s",
+                 label.c_str(), p.source_width, p.source_height, p.x, p.y, p.crop_width, p.crop_height,
+                 p.resize_width, p.resize_height, p.pad_x, p.pad_y, p.width, p.height, filter.c_str(), static_cast<int>(mode), BOOL_STR(antialias));
+        return output;
+    }
+
+    Tensor<float> ImagePreprocessor::apply_geometry(const Tensor<float>& image, ImageTarget target, int index, int width, int height, ImageResizeMode default_mode, ops::InterpolateMode default_filter, ImageTransform* plan_out) const {
+        if (!valid_ || image.empty())
+            return {};
+        const std::string label = std::string(enum_name(target, image_targets)) + "[" + std::to_string(index) + "]";
+        auto options            = resolve_options(target, index);
+        if (image.dim() != 4 || image.shape()[3] != 1 || image.shape()[2] < 1 || image.shape()[2] > 4) {
+            fail(label + ": expected one image with 1 to 4 channels");
+            return {};
+        }
+        ImageTransform p;
+        p.source_width = p.crop_width = static_cast<int>(image.shape()[0]);
+        p.source_height = p.crop_height = static_cast<int>(image.shape()[1]);
+        int target_width                = width > 0 ? width : p.source_width;
+        int target_height               = height > 0 ? height : p.source_height;
+        if (options.count("width")) {
+            parse_strict_int(options.at("width"), target_width);
+            parse_strict_int(options.at("height"), target_height);
+        }
+        ImageResizeMode mode = resolve_mode(options, default_mode);
+        std::string anchor   = options.count("anchor") ? options.at("anchor") : "center";
+        p.width = p.resize_width = target_width;
+        p.height = p.resize_height = target_height;
+        if (mode == ImageResizeMode::None) {
+            if (options.count("width") && (target_width != p.source_width || target_height != p.source_height)) {
+                fail(label + ": mode=none conflicts with requested dimensions");
+                return {};
+            }
+            p.width = p.resize_width = p.source_width;
+            p.height = p.resize_height = p.source_height;
+        } else if (mode == ImageResizeMode::Crop || mode == ImageResizeMode::CropResize) {
+            if (mode == ImageResizeMode::Crop) {
+                p.crop_width  = target_width;
+                p.crop_height = target_height;
+            } else if (int64_t(p.source_width) * target_height > int64_t(p.source_height) * target_width) {
+                p.crop_width = std::max(1, static_cast<int>(int64_t(p.source_height) * target_width / target_height));
+            } else {
+                p.crop_height = std::max(1, static_cast<int>(int64_t(p.source_width) * target_height / target_width));
+            }
+            if (p.crop_width > p.source_width || p.crop_height > p.source_height) {
+                fail(label + ": crop exceeds source dimensions");
+                return {};
+            }
+            p.x = anchor_offset(p.source_width - p.crop_width, anchor, true);
+            p.y = anchor_offset(p.source_height - p.crop_height, anchor, false);
+        } else if (mode == ImageResizeMode::FitPad) {
+            double scale    = std::min(double(target_width) / p.source_width, double(target_height) / p.source_height);
+            p.resize_width  = std::max(1, std::min(target_width, static_cast<int>(std::round(p.source_width * scale))));
+            p.resize_height = std::max(1, std::min(target_height, static_cast<int>(std::round(p.source_height * scale))));
+            p.pad_x         = anchor_offset(target_width - p.resize_width, anchor, true);
+            p.pad_y         = anchor_offset(target_height - p.resize_height, anchor, false);
+        }
+        if (p.width <= 0 || p.height <= 0) {
+            fail(label + ": invalid output dimensions");
+            return {};
+        }
+        uint64_t max_pixels = std::min<uint64_t>(INT64_MAX, SIZE_MAX / sizeof(float)) / static_cast<uint64_t>(image.shape()[2]);
+        if (uint64_t(p.width) * p.height > max_pixels || uint64_t(p.resize_width) * p.resize_height > max_pixels) {
+            fail(label + ": image allocation size overflows");
+            return {};
+        }
+        if (plan_out != nullptr)
+            *plan_out = p;
+        return apply_transform(image, options, p, label, default_filter);
+    }
+
+    Tensor<float> ImagePreprocessor::preprocess_input(sd_image_t image, ImageTarget target, int index, int width, int height) {
+        if (image.data == nullptr || image.width == 0 || image.height == 0 || image.width > INT_MAX || image.height > INT_MAX || image.channel < 1 || image.channel > 4) {
+            fail(std::string(enum_name(target, image_targets)) + ": invalid input image");
+            return {};
+        }
+        auto tensor = sd_image_to_tensor(image);
+        if (target == ImageTarget::Mask && has_init_transform_) {
+            auto options = resolve_options(target, index);
+            if (image.width != init_transform_.source_width || image.height != init_transform_.source_height) {
+                fail("mask and init source dimensions must match");
+                return {};
+            }
+            bool geometry_override = options.count("width") || options.count("anchor") ||
+                                     (options.count("mode") && options.at("mode") != "auto");
+            if (geometry_override) {
+                ImageTransform p;
+                auto init_options            = resolve_options(ImageTarget::Init, 0);
+                ImageResizeMode default_mode = resolve_mode(init_options, ImageResizeMode::CropResize);
+                auto result                  = apply_geometry(tensor, target, index, init_transform_.width, init_transform_.height, default_mode, ops::InterpolateMode::NearestExact, &p);
+                if (result.empty())
+                    return {};
+                const auto& q = init_transform_;
+                if (p.x != q.x || p.y != q.y || p.crop_width != q.crop_width || p.crop_height != q.crop_height ||
+                    p.resize_width != q.resize_width || p.resize_height != q.resize_height || p.pad_x != q.pad_x || p.pad_y != q.pad_y || p.width != q.width || p.height != q.height) {
+                    fail("mask geometry conflicts with init; configure geometry on init and filter on mask");
+                    return {};
+                }
+                return result;
+            }
+            return apply_transform(tensor, options, init_transform_, "mask[0]", ops::InterpolateMode::NearestExact);
+        }
+        auto result = apply_geometry(tensor, target, index, width, height, width > 0 ? ImageResizeMode::CropResize : ImageResizeMode::None,
+                                     target == ImageTarget::Mask ? ops::InterpolateMode::NearestExact : ops::InterpolateMode::Nearest,
+                                     target == ImageTarget::Init ? &init_transform_ : nullptr);
+        if (target == ImageTarget::Init)
+            has_init_transform_ = !result.empty();
+        return result;
+    }
+
+    ImagePreprocessor::~ImagePreprocessor() {
+        for (const auto& image : owned_images_)
+            std::free(image.data);
+    }
+
+    bool ImagePreprocessor::prepare_image(sd_image_t& image, ImageTarget target, int index, int width, int height) {
+        if (image.data == nullptr)
+            return true;
+        auto options = resolve_options(target, index);
+        bool canny   = options.count("canny") && options.at("canny") == "true";
+        auto tensor  = preprocess_input(image, target, index, width, height);
+        if (tensor.empty())
+            return false;
+        auto output = tensor_to_sd_image(tensor);
+        if (output.data == nullptr)
+            return fail("could not allocate input preprocessing buffer");
+        owned_images_.push_back(output);
+        if (canny && !preprocess_canny(output, 0.08f, 0.08f, 0.8f, 1.f, false))
+            return fail("Canny preprocessing failed");
+        image = output;
+        return true;
+    }
+
+    bool ImagePreprocessor::prepare_array(sd_image_t*& images, int count, ImageTarget target, std::vector<sd_image_t>& storage, int width, int height) {
+        if (count < 0 || (count > 0 && images == nullptr))
+            return fail(std::string("invalid image array: ") + enum_name(target, image_targets));
+        if (count == 0)
+            return true;
+        storage.assign(images, images + count);
+        for (int i = 0; i < count; ++i) {
+            if (storage[i].data == nullptr)
+                return fail(std::string("empty image in array: ") + enum_name(target, image_targets));
+            if (!prepare_image(storage[i], target, i, width, height))
+                return false;
+        }
+        images = storage.data();
+        return true;
+    }
+
+    bool ImagePreprocessor::prepare_inputs(sd_img_gen_params_t& params, int width, int height) {
+        if (prepared_)
+            return fail("inputs have already been prepared");
+        prepared_ = true;
+        if (!valid_ || !validate_inputs(params))
+            return false;
+        if (!prepare_image(params.init_image, ImageTarget::Init, 0, width, height) ||
+            !prepare_image(params.mask_image, ImageTarget::Mask, 0, width, height) ||
+            !prepare_image(params.control_image, ImageTarget::Control, 0, width, height) ||
+            !prepare_image(params.ip_adapter_image, ImageTarget::IPAdapter, 0, -1, -1) ||
+            !prepare_array(params.ref_images, params.ref_images_count, ImageTarget::Ref, ref_images_) ||
+            !prepare_array(params.pm_params.id_images, params.pm_params.id_images_count, ImageTarget::ID, id_images_))
+            return false;
+        params.image_preprocess = {};
+        return true;
+    }
+
+    bool ImagePreprocessor::prepare_inputs(sd_vid_gen_params_t& params, int width, int height) {
+        if (prepared_)
+            return fail("inputs have already been prepared");
+        prepared_ = true;
+        if (!valid_ || !validate_inputs(params))
+            return false;
+        if (!prepare_image(params.init_image, ImageTarget::Init, 0, width, height) ||
+            !prepare_image(params.end_image, ImageTarget::End, 0, width, height) ||
+            !prepare_array(params.ref_images, params.ref_images_count, ImageTarget::Ref, ref_images_) ||
+            !prepare_array(params.control_frames, params.control_frames_size, ImageTarget::ControlFrame, control_frames_, width, height))
+            return false;
+        params.image_preprocess = {};
+        return true;
+    }
+
+}  // namespace sd

src/runtime/image_preprocess.h

@@ -0,0 +1,88 @@
+#ifndef __SD_RUNTIME_IMAGE_PREPROCESS_H__
+#define __SD_RUNTIME_IMAGE_PREPROCESS_H__
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "core/tensor.hpp"
+#include "stable-diffusion.h"
+
+namespace sd {
+
+    enum class ImageTarget {
+        Init,
+        End,
+        Mask,
+        Control,
+        Ref,
+        IPAdapter,
+        ID,
+        ControlFrame,
+    };
+
+    enum class ImageResizeMode {
+        Auto,
+        None,
+        Stretch,
+        Crop,
+        CropResize,
+        FitPad,
+    };
+
+    struct ImageTransform {
+        int source_width  = 0;
+        int source_height = 0;
+        int x             = 0;
+        int y             = 0;
+        int crop_width    = 0;
+        int crop_height   = 0;
+        int resize_width  = 0;
+        int resize_height = 0;
+        int width         = 0;
+        int height        = 0;
+        int pad_x         = 0;
+        int pad_y         = 0;
+    };
+
+    struct ImagePreprocessRule {
+        ImageTarget target = ImageTarget::Init;
+        int index          = -1;
+        std::map<std::string, std::string> options;
+    };
+
+    class ImagePreprocessor {
+        std::vector<ImagePreprocessRule> rules_;
+        mutable bool valid_ = true;
+        ImageTransform init_transform_;
+        bool has_init_transform_ = false;
+        bool prepared_           = false;
+        std::vector<sd_image_t> owned_images_;
+        std::vector<sd_image_t> ref_images_;
+        std::vector<sd_image_t> id_images_;
+        std::vector<sd_image_t> control_frames_;
+
+        bool fail(const std::string& message) const;
+        std::map<std::string, std::string> resolve_options(ImageTarget target, int index) const;
+        Tensor<float> apply_transform(const Tensor<float>& image, const std::map<std::string, std::string>& options, ImageTransform plan, const std::string& label, ops::InterpolateMode default_filter) const;
+
+        bool prepare_image(sd_image_t& image, ImageTarget target, int index, int width, int height);
+        bool prepare_array(sd_image_t*& images, int count, ImageTarget target, std::vector<sd_image_t>& storage, int width = -1, int height = -1);
+
+    public:
+        explicit ImagePreprocessor(const char* rules = nullptr);
+        ~ImagePreprocessor();
+        ImagePreprocessor(const ImagePreprocessor&)            = delete;
+        ImagePreprocessor& operator=(const ImagePreprocessor&) = delete;
+        bool prepare_inputs(sd_img_gen_params_t& params, int width, int height);
+        bool prepare_inputs(sd_vid_gen_params_t& params, int width, int height);
+        bool is_valid() const { return valid_; }
+        bool validate_inputs(const sd_img_gen_params_t& params) const;
+        bool validate_inputs(const sd_vid_gen_params_t& params) const;
+        Tensor<float> apply_geometry(const Tensor<float>& image, ImageTarget target, int index, int width, int height, ImageResizeMode default_mode = ImageResizeMode::Stretch, ops::InterpolateMode default_filter = ops::InterpolateMode::Nearest, ImageTransform* plan_out = nullptr) const;
+        Tensor<float> preprocess_input(sd_image_t image, ImageTarget target, int index = 0, int width = -1, int height = -1);
+    };
+
+}  // namespace sd
+
+#endif  // __SD_RUNTIME_IMAGE_PREPROCESS_H__

src/runtime/latent-preview.h

@@ -4,6 +4,86 @@
 #include "core/tensor.hpp"
 #include "ggml.h"
 
+// RGB is projected to [-1, 1]; alpha is projected directly to [0, 1].
+const float qwen21_latent_rgb_proj[64][3] = {
+    {0.00860495522f, 0.01219501462f, -0.00321337196f},
+    {0.01889233090f, 0.01246581216f, 0.01074959482f},
+    {0.1255941446f, 0.1176879344f, -0.0332212352f},
+    {0.0418238528f, 0.1043427754f, 0.0121666316f},
+    {0.02025338f, 0.01453670296f, -0.000224336044f},
+    {-0.01896720702f, -0.0206099030f, -0.0322728584f},
+    {0.00438984796f, -0.01374969766f, 0.02849196f},
+    {-0.0374495856f, -0.0286777126f, -0.0693192810f},
+    {0.01511914734f, 0.0242979386f, 0.0553878870f},
+    {-0.1138629518f, -0.020391466f, 0.001550520522f},
+    {-0.0233650696f, -0.0417292018f, -0.0362361182f},
+    {-0.0351603342f, -0.0243595924f, -0.00216261038f},
+    {0.01093355288f, -0.0373466924f, 0.00241315350f},
+    {0.01778704744f, -0.00401984678f, -0.0343259192f},
+    {0.0486059334f, 0.0253144f, 0.0672564966f},
+    {0.0309463558f, 0.0277963166f, 0.0520869622f},
+    {0.0374485008f, 0.0551753676f, 0.0225853902f},
+    {-0.0090809962f, -0.004756176f, 0.00636443612f},
+    {-0.0270455652f, -0.0384966954f, -0.00905908082f},
+    {-0.00553493756f, 0.01484553684f, -0.0211502468f},
+    {0.01319502562f, 0.00948005666f, 0.0483789212f},
+    {-0.00931847104f, -0.00276452734f, -0.01011985302f},
+    {0.0180478258f, 0.01614954356f, -0.0209424690f},
+    {-0.0214530434f, -0.00272961176f, 0.0217887476f},
+    {-0.0636772304f, -0.0208893548f, 0.0479167742f},
+    {-0.0250321236f, -0.0286715676f, 0.0530110146f},
+    {-0.01853078078f, 0.01647272818f, -0.00207747588f},
+    {0.0023101082f, 0.01228800748f, 0.01303505006f},
+    {-0.01243671408f, -0.0258638728f, -0.0379116264f},
+    {0.00598934710f, 0.00642563550f, -0.01234514304f},
+    {-0.0296733996f, -0.0234698050f, 0.00060018212f},
+    {-0.0322019498f, -0.0529200462f, -0.00344987414f},
+    {-0.00205026458f, -0.00846599446f, 0.00455971038f},
+    {-0.01082227064f, 0.0315661948f, -0.0677753362f},
+    {0.0645553474f, 0.1109666998f, 0.0674744864f},
+    {0.01036801108f, -0.00484841210f, -0.001529168474f},
+    {0.01264353566f, 0.01548126338f, -0.00966374324f},
+    {-0.0223892408f, -0.00871751526f, -0.000306421670f},
+    {0.0271322742f, 0.03496524f, -0.0089692858f},
+    {0.0512178672f, 0.0173080034f, 0.00804227746f},
+    {0.01210987192f, 0.00758025926f, -0.00281712586f},
+    {0.1897278390f, 0.1210261828f, 0.062603892f},
+    {0.0208058822f, 0.00547548182f, 0.01262955638f},
+    {0.00813332858f, 0.01015930914f, 0.01301771290f},
+    {-0.000927236014f, -0.00152540594f, -0.00599213302f},
+    {0.01663314616f, -0.00582789626f, 0.0163958132f},
+    {-0.0252546342f, -0.0604193732f, -0.1606919922f},
+    {-0.091722686f, -0.0409201224f, -0.0959576198f},
+    {0.0282963112f, -0.01387223872f, -0.01648814464f},
+    {0.0552316818f, 0.0967547788f, 0.0413586632f},
+    {0.00922849292f, 0.00451467542f, -0.0529172378f},
+    {0.0558600768f, 0.0122988308f, -0.01445942422f},
+    {0.000210660902f, -0.01295958782f, -0.01804761764f},
+    {0.0358136250f, -0.0472505970f, -0.1156405142f},
+    {-0.0506390696f, -0.0471914842f, 0.0349791468f},
+    {-0.0480143168f, 0.00628389868f, -0.0545163826f},
+    {0.0315499582f, 0.0564846606f, -0.0430850488f},
+    {-0.0362330316f, -0.01267788554f, 0.0061024772f},
+    {0.0038627542f, 0.00911055916f, -0.00758526008f},
+    {-0.0447103298f, -0.00835411408f, 0.01545872328f},
+    {-0.015006738f, 0.00270612302f, -0.00784361356f},
+    {-0.0221755048f, -0.0513344748f, -0.0475317424f},
+    {-0.01036656294f, -0.00422146068f, -0.0213499052f},
+    {0.01788952706f, 0.01191944190f, 0.0397205238f},
+};
+float qwen21_latent_rgb_bias[3] = {-0.043293118f, -0.02695978f, -0.11986706f};
+
+const float qwen21_latent_alpha_proj[64] = {
+    -0.0416241114f, -0.00678954612f, -0.0169095515f, -0.0230551401f, 0.0100882595f, 0.00655586802f, 0.0401166874f, -0.0055510216f,
+    0.0224234441f, -0.0389640963f, -0.0114492163f, -0.00721128977f, -0.0029064082f, 0.0150300547f, -0.00321615308f, -0.0498856338f,
+    -0.0215251401f, 0.0240220482f, 0.0117338008f, -0.0460420624f, 0.0387872889f, 0.0131517207f, 0.0147100836f, 0.0266985286f,
+    0.0153097324f, -0.0418119757f, 0.0421013917f, 0.0401724499f, 0.00972515915f, 0.011718495f, 0.0117622291f, 0.0136505134f,
+    -0.0350017363f, -0.0100692606f, -0.0131582529f, -0.00660639315f, 0.00253611396f, -0.0195736368f, -0.04240184f, 0.0321299262f,
+    0.0106089414f, -0.0179845306f, -0.00806212708f, 0.0135889057f, -0.0157393098f, -0.0267791344f, 0.0109068534f, 0.0283931966f,
+    -0.0435370078f, 0.00187883536f, -0.0108995378f, -0.0450757676f, -0.0699481501f, 0.0123562106f, -0.0222592249f, 0.0216155907f,
+    0.0563755424f, -0.0073379912f, 0.0160012921f, 0.0411637742f, 0.0189607258f, -0.024025029f, -0.0161487905f, -0.016913203f};
+const float qwen21_latent_alpha_bias = 0.871268134f;
+
 const float minimax_latent_rgb_proj[24][3] = {
     {0.19819857f, 0.11584999f, 0.07929777f},
     {-0.16047224f, -0.10601170f, -0.15996324f},
@@ -324,7 +404,7 @@ const float sd_latent_rgb_proj[4][3] = {
     {-0.178022f, -0.200862f, -0.678514f}};
 float sd_latent_rgb_bias[3] = {-0.017478f, -0.055834f, -0.105825f};
 
-void preview_latent_video(uint8_t* buffer, ggml_tensor* latents, const float (*latent_rgb_proj)[3], const float latent_rgb_bias[3], int patch_size) {
+void preview_latent_video(uint8_t* buffer, ggml_tensor* latents, const float (*latent_rgb_proj)[3], const float latent_rgb_bias[3], int patch_size, const float* latent_alpha_proj = nullptr, float latent_alpha_bias = 1.f) {
     size_t buffer_head = 0;
 
     uint32_t latent_width  = static_cast<uint32_t>(latents->ne[0]);
@@ -338,7 +418,8 @@ void preview_latent_video(uint8_t* buffer, ggml_tensor* latents, const float (*l
     uint32_t rgb_width  = latent_width * patch_size;
     uint32_t rgb_height = latent_height * patch_size;
 
-    uint32_t unpatched_dim = dim / (patch_size * patch_size);
+    uint32_t unpatched_dim         = dim / (patch_size * patch_size);
+    const uint32_t output_channels = latent_alpha_proj != nullptr ? 4 : 3;
 
     for (uint32_t k = 0; k < frames; k++) {
         for (uint32_t rgb_x = 0; rgb_x < rgb_width; rgb_x++) {
@@ -356,13 +437,16 @@ void preview_latent_video(uint8_t* buffer, ggml_tensor* latents, const float (*l
                 // should be incremented by 1 for each pixel
                 size_t pixel_id = k * rgb_width * rgb_height + rgb_y * rgb_width + rgb_x;
 
-                float r = 0, g = 0, b = 0;
+                float r = 0, g = 0, b = 0, a = 0;
                 if (latent_rgb_proj != nullptr) {
                     for (uint32_t d = 0; d < unpatched_dim; d++) {
                         float value = *(float*)((char*)latents->data + latent_id + (d * patch_size * patch_size + channel_offset) * latents->nb[ggml_n_dims(latents) - 1]);
                         r += value * latent_rgb_proj[d][0];
                         g += value * latent_rgb_proj[d][1];
                         b += value * latent_rgb_proj[d][2];
+                        if (latent_alpha_proj != nullptr) {
+                            a += value * latent_alpha_proj[d];
+                        }
                     }
                 } else {
                     // interpret first 3 channels as RGB
@@ -386,9 +470,13 @@ void preview_latent_video(uint8_t* buffer, ggml_tensor* latents, const float (*l
                 g = g >= 0 ? g <= 1 ? g : 1 : 0;
                 b = b >= 0 ? b <= 1 ? b : 1 : 0;
 
-                buffer[pixel_id * 3 + 0] = (uint8_t)(r * 255);
-                buffer[pixel_id * 3 + 1] = (uint8_t)(g * 255);
-                buffer[pixel_id * 3 + 2] = (uint8_t)(b * 255);
+                buffer[pixel_id * output_channels + 0] = (uint8_t)(r * 255);
+                buffer[pixel_id * output_channels + 1] = (uint8_t)(g * 255);
+                buffer[pixel_id * output_channels + 2] = (uint8_t)(b * 255);
+                if (latent_alpha_proj != nullptr) {
+                    a                                      = std::min(1.0f, std::max(0.0f, a + latent_alpha_bias));
+                    buffer[pixel_id * output_channels + 3] = (uint8_t)(a * 255);
+                }
             }
         }
     }
@@ -398,16 +486,17 @@ static inline bool preview_latent_tensor_is_video(const sd::Tensor<float>& laten
     return latents.dim() == 5;
 }
 
-void preview_latent_video(uint8_t* buffer, const sd::Tensor<float>& latents, const float (*latent_rgb_proj)[3], const float latent_rgb_bias[3], int patch_size) {
+void preview_latent_video(uint8_t* buffer, const sd::Tensor<float>& latents, const float (*latent_rgb_proj)[3], const float latent_rgb_bias[3], int patch_size, const float* latent_alpha_proj = nullptr, float latent_alpha_bias = 1.f) {
     uint32_t latent_width  = static_cast<uint32_t>(latents.shape()[0]);
     uint32_t latent_height = static_cast<uint32_t>(latents.shape()[1]);
     bool is_video          = preview_latent_tensor_is_video(latents);
     uint32_t frames        = is_video ? static_cast<uint32_t>(latents.shape()[2]) : 1;
     uint32_t dim           = is_video ? static_cast<uint32_t>(latents.shape()[3]) : static_cast<uint32_t>(latents.shape()[2]);
 
-    uint32_t rgb_width     = latent_width * patch_size;
-    uint32_t rgb_height    = latent_height * patch_size;
-    uint32_t unpatched_dim = dim / (patch_size * patch_size);
+    uint32_t rgb_width             = latent_width * patch_size;
+    uint32_t rgb_height            = latent_height * patch_size;
+    uint32_t unpatched_dim         = dim / (patch_size * patch_size);
+    const uint32_t output_channels = latent_alpha_proj != nullptr ? 4 : 3;
 
     for (uint32_t k = 0; k < frames; k++) {
         for (uint32_t rgb_x = 0; rgb_x < rgb_width; rgb_x++) {
@@ -427,7 +516,7 @@ void preview_latent_video(uint8_t* buffer, const sd::Tensor<float>& latents, con
                                : latents.values()[latent_x + latent_width * (latent_y + latent_height * latent_channel)];
                 };
 
-                float r = 0.f, g = 0.f, b = 0.f;
+                float r = 0.f, g = 0.f, b = 0.f, a = 0.f;
                 if (latent_rgb_proj != nullptr) {
                     for (uint32_t d = 0; d < unpatched_dim; d++) {
                         uint32_t latent_channel = d * patch_size * patch_size + channel_offset;
@@ -435,6 +524,9 @@ void preview_latent_video(uint8_t* buffer, const sd::Tensor<float>& latents, con
                         r += value * latent_rgb_proj[d][0];
                         g += value * latent_rgb_proj[d][1];
                         b += value * latent_rgb_proj[d][2];
+                        if (latent_alpha_proj != nullptr) {
+                            a += value * latent_alpha_proj[d];
+                        }
                     }
                 } else {
                     r = latent_value(0);
@@ -450,9 +542,13 @@ void preview_latent_video(uint8_t* buffer, const sd::Tensor<float>& latents, con
                 g = std::min(1.0f, std::max(0.0f, g * .5f + .5f));
                 b = std::min(1.0f, std::max(0.0f, b * .5f + .5f));
 
-                buffer[pixel_id * 3 + 0] = (uint8_t)(r * 255);
-                buffer[pixel_id * 3 + 1] = (uint8_t)(g * 255);
-                buffer[pixel_id * 3 + 2] = (uint8_t)(b * 255);
+                buffer[pixel_id * output_channels + 0] = (uint8_t)(r * 255);
+                buffer[pixel_id * output_channels + 1] = (uint8_t)(g * 255);
+                buffer[pixel_id * output_channels + 2] = (uint8_t)(b * 255);
+                if (latent_alpha_proj != nullptr) {
+                    a                                      = std::min(1.0f, std::max(0.0f, a + latent_alpha_bias));
+                    buffer[pixel_id * output_channels + 3] = (uint8_t)(a * 255);
+                }
             }
         }
     }

src/runtime/preprocessing.hpp

@@ -165,16 +165,18 @@ static inline sd::Tensor<float> convolve_tensor(const sd::Tensor<float>& input,
     return output;
 }
 
-static inline sd::Tensor<float> grayscale_tensor(const sd::Tensor<float>& rgb_img) {
-    GGML_ASSERT(rgb_img.dim() == 4);
-    GGML_ASSERT(rgb_img.shape()[2] >= 3);
-    sd::Tensor<float> grayscale({rgb_img.shape()[0], rgb_img.shape()[1], 1, rgb_img.shape()[3]});
-    for (int64_t iy = 0; iy < rgb_img.shape()[1]; ++iy) {
-        for (int64_t ix = 0; ix < rgb_img.shape()[0]; ++ix) {
-            float r    = preprocessing_get_4d(rgb_img, ix, iy, 0, 0);
-            float g    = preprocessing_get_4d(rgb_img, ix, iy, 1, 0);
-            float b    = preprocessing_get_4d(rgb_img, ix, iy, 2, 0);
-            float gray = 0.2989f * r + 0.5870f * g + 0.1140f * b;
+static inline sd::Tensor<float> grayscale_tensor(const sd::Tensor<float>& image) {
+    GGML_ASSERT(image.dim() == 4);
+    GGML_ASSERT(image.shape()[2] >= 1);
+    sd::Tensor<float> grayscale({image.shape()[0], image.shape()[1], 1, image.shape()[3]});
+    for (int64_t iy = 0; iy < image.shape()[1]; ++iy) {
+        for (int64_t ix = 0; ix < image.shape()[0]; ++ix) {
+            float gray = preprocessing_get_4d(image, ix, iy, 0, 0);
+            if (image.shape()[2] >= 3) {
+                float g = preprocessing_get_4d(image, ix, iy, 1, 0);
+                float b = preprocessing_get_4d(image, ix, iy, 2, 0);
+                gray    = 0.2989f * gray + 0.5870f * g + 0.1140f * b;
+            }
             preprocessing_set_4d(grayscale, gray, ix, iy, 0, 0);
         }
     }
@@ -317,11 +319,12 @@ bool preprocess_canny(sd_image_t img, float high_threshold, float low_threshold,
     image_gray              = non_max_supression(G, theta);
     threshold_hystersis(&image_gray, high_threshold, low_threshold, weak, strong);
 
+    const uint32_t color_channels = img.channel == 2 || img.channel == 4 ? img.channel - 1 : img.channel;
     for (uint32_t iy = 0; iy < img.height; ++iy) {
         for (uint32_t ix = 0; ix < img.width; ++ix) {
             float gray = preprocessing_get_4d(image_gray, ix, iy, 0, 0);
             gray       = inverse ? 1.0f - gray : gray;
-            for (uint32_t c = 0; c < img.channel; ++c) {
+            for (uint32_t c = 0; c < color_channels; ++c) {
                 preprocessing_set_4d(image, gray, ix, iy, c, 0);
             }
         }

src/stable-diffusion.cpp

@@ -326,6 +326,7 @@ void sd_hires_params_init(sd_hires_params_t* hires_params) {
 void sd_ctx_params_init(sd_ctx_params_t* sd_ctx_params) {
     *sd_ctx_params                           = {};
     sd_ctx_params->n_threads                 = sd_get_num_physical_cores();
+    sd_ctx_params->conditioning_cache_size   = 4;
     sd_ctx_params->wtype                     = SD_TYPE_COUNT;
     sd_ctx_params->rng_type                  = CUDA_RNG;
     sd_ctx_params->sampler_rng_type          = RNG_TYPE_COUNT;
@@ -378,6 +379,7 @@ char* sd_ctx_params_to_str(const sd_ctx_params_t* sd_ctx_params) {
              "pulid_weights_path: %s\n"
              "tensor_type_rules: %s\n"
              "n_threads: %d\n"
+             "conditioning_cache_size: %d\n"
              "wtype: %s\n"
              "rng_type: %s\n"
              "sampler_rng_type: %s\n"
@@ -418,6 +420,7 @@ char* sd_ctx_params_to_str(const sd_ctx_params_t* sd_ctx_params) {
              SAFE_STR(sd_ctx_params->pulid_weights_path),
              SAFE_STR(sd_ctx_params->tensor_type_rules),
              sd_ctx_params->n_threads,
+             sd_ctx_params->conditioning_cache_size,
              sd_type_name(sd_ctx_params->wtype),
              sd_rng_type_name(sd_ctx_params->rng_type),
              sd_rng_type_name(sd_ctx_params->sampler_rng_type),
@@ -751,28 +754,20 @@ SD_API bool generate_video(sd_ctx_t* sd_ctx,
                            int* num_frames_out,
                            sd_audio_t** audio_out,
                            int* fps_out) {
-    if (sd_ctx == nullptr || sd_ctx->sd == nullptr || sd_vid_gen_params == nullptr) {
-        if (fps_out != nullptr) {
-            *fps_out = 0;
-        }
-        return false;
-    }
-
-    if (frames_out != nullptr) {
+    if (frames_out != nullptr)
         *frames_out = nullptr;
-    }
-    if (audio_out != nullptr) {
+    if (audio_out != nullptr)
         *audio_out = nullptr;
-    }
-    if (num_frames_out != nullptr) {
+    if (num_frames_out != nullptr)
         *num_frames_out = 0;
+    if (fps_out != nullptr)
+        *fps_out = 0;
+    if (sd_ctx == nullptr || sd_ctx->sd == nullptr || sd_vid_gen_params == nullptr) {
+        return false;
     }
 
     StableDiffusionGGML::ExecutionScope execution(*sd_ctx->sd);
     if (!execution.ready) {
-        if (fps_out != nullptr) {
-            *fps_out = 0;
-        }
         return false;
     }
 

src/upscaler.cpp

@@ -111,10 +111,22 @@ bool UpscalerGGML::load_from_file(const std::string& esrgan_path,
 
 sd::Tensor<float> UpscalerGGML::upscale_tensor(const sd::Tensor<float>& input_tensor) {
     sd::ParallelScope tensor_scope(&tensor_executor);
+    if (input_tensor.empty() || input_tensor.dim() != 4 ||
+        (input_tensor.shape()[2] != 3 && input_tensor.shape()[2] != 4)) {
+        LOG_ERROR("esrgan expects a 4D RGB or RGBA image tensor");
+        return {};
+    }
+
+    const bool has_alpha = input_tensor.shape()[2] == 4;
+    sd::Tensor<float> rgb;
+    if (has_alpha) {
+        rgb = sd::ops::slice(input_tensor, 2, 0, 3);
+    }
+    const sd::Tensor<float>& model_input = has_alpha ? rgb : input_tensor;
     sd::Tensor<float> upscaled;
     const int scale = esrgan_upscaler->config.scale;
     if (tile_size <= 0 || (input_tensor.shape()[0] <= tile_size && input_tensor.shape()[1] <= tile_size)) {
-        upscaled = esrgan_upscaler->compute(n_threads, input_tensor);
+        upscaled = esrgan_upscaler->compute(n_threads, model_input);
     } else {
         auto on_processing = [&](const sd::Tensor<float>& input_tile) -> sd::Tensor<float> {
             auto output_tile = esrgan_upscaler->compute(n_threads, input_tile);
@@ -125,7 +137,7 @@ sd::Tensor<float> UpscalerGGML::upscale_tensor(const sd::Tensor<float>& input_te
             return output_tile;
         };
 
-        upscaled = process_tiles_2d(input_tensor,
+        upscaled = process_tiles_2d(model_input,
                                     static_cast<int>(input_tensor.shape()[0] * scale),
                                     static_cast<int>(input_tensor.shape()[1] * scale),
                                     scale,
@@ -141,6 +153,14 @@ sd::Tensor<float> UpscalerGGML::upscale_tensor(const sd::Tensor<float>& input_te
         LOG_ERROR("esrgan compute failed");
         return {};
     }
+    if (has_alpha) {
+        auto alpha       = sd::ops::slice(input_tensor, 2, 3, 4);
+        auto alpha_shape = alpha.shape();
+        alpha_shape[0]   = upscaled.shape()[0];
+        alpha_shape[1]   = upscaled.shape()[1];
+        alpha            = sd::ops::interpolate(alpha, alpha_shape, sd::ops::InterpolateMode::Bilinear);
+        upscaled         = sd::ops::concat(upscaled, alpha, 2);
+    }
     return upscaled;
 }