Add Gemma4 image_processor.json generation with onnxruntime-extension…

src/mobius/integrations/ort_genai/auto_export.py

@@ -173,30 +173,49 @@ def _write_processor_config(
     model_type = getattr(config, "model_type", "")
 
     if model_type in ("gemma4", "gemma4_text"):
-        # Gemma4 needs a processor wrapper with model-specific fields
-        tokens_per_image = (
+        # Gemma4 needs an onnxruntime-extensions format processor config
+        # with a transforms pipeline (DecodeImage -> Gemma4ImageTransform).
+        # The OrtxCreateProcessor API requires this format.
+        max_soft_tokens = (
             getattr(vision, "mm_tokens_per_image", None)
             or getattr(config, "mm_tokens_per_image", None)
             or getattr(vision, "max_soft_tokens", None)
             or 280
         )
-        image_size = getattr(vision, "image_size", None) or 448
         patch_size = getattr(vision, "patch_size", None) or 16
-        processor: dict[str, Any] = {
+        pooling_kernel_size = getattr(vision, "pooling_kernel_size", None) or 3
+        processor = {
             "processor": {
-                "name": "gemma4_image_processor",
-                "image_size": image_size,
-                "patch_size": patch_size,
-                "tokens_per_image": tokens_per_image,
+                "name": "gemma_4_image_processing",
+                "transforms": [
+                    {
+                        "operation": {
+                            "name": "decode_image",
+                            "type": "DecodeImage",
+                            "attrs": {"color_space": "RGB"},
+                        }
+                    },
+                    {
+                        "operation": {
+                            "name": "gemma4_image_transform",
+                            "type": "Gemma4ImageTransform",
+                            "attrs": {
+                                "patch_size": patch_size,
+                                "max_soft_tokens": max_soft_tokens,
+                                "pooling_kernel_size": pooling_kernel_size,
+                            },
+                        }
+                    },
+                ],
             }
         }
+        proc_filename = "image_processor.json"
     else:
         processor = {
             "image_size": getattr(vision, "image_size", None) or 448,
             "patch_size": getattr(vision, "patch_size", None) or 14,
         }
-
-    proc_filename = "processor_config.json"
+        proc_filename = "processor_config.json"
 
     path = os.path.join(output_dir, proc_filename)
     with open(path, "w", encoding="utf-8") as f:
@@ -280,6 +299,7 @@ def _write_genai_config(
                 vision_cfg = getattr(config, "vision", None)
                 sms = getattr(vision_cfg, "spatial_merge_size", 2)
                 vision_kwargs["spatial_merge_size"] = sms
+                vision_kwargs["config_filename"] = "image_processor.json"
 
             if vision_input_mapping is not None:
                 vision_kwargs["input_names"] = vision_input_mapping

src/mobius/integrations/ort_genai/auto_export_test.py

@@ -780,7 +780,7 @@ def test_gemma4_genai_config_from_real_model(self, tmp_path):
         # Config-level properties are still present
         assert data["model"]["image_token_id"] == 255999
         assert data["model"]["vision"]["spatial_merge_size"] == 2
-        assert data["model"]["vision"]["config_filename"] == "processor_config.json"
+        assert data["model"]["vision"]["config_filename"] == "image_processor.json"
 
     def test_auto_export_produces_genai_config(self, tmp_path):
         """Mock build() to return a tiny package, verify genai_config."""