Add SeedVR2 7B upscale image test support. (#360)

Co-authored-by: Cursor Assistant <assistant@cursor.com>

Author: filipstrand

src/mflux/models/seedvr2/README.md

@@ -41,10 +41,16 @@ Instead of specifying a target resolution, you can also use `--resolution 2x` or
 
 You can also adjust the `--softness` parameter (0.0 to 1.0) to control input pre-downsampling, which can help achieve smoother upscaling results. A value of 0.0 (default) disables pre-downsampling, while higher values up to 1.0 increase the downsampling factor (up to 8x internally) before upscaling. A value of `0.5` is often a good starting point.
 
+> [!NOTE]
+> Upscaling to very large resolutions can require a lot of memory. If you run into memory pressure, try `--low-ram` or set an MLX cache limit with `--mlx-cache-limit-gb 16` (replace `16` with a value that fits your machine).
+
 ## Upscale a Directory
 
 Pass a directory to `--image-path` to upscale every image inside.
 
+> [!WARNING]
+> `--low-ram` is not supported when upscaling a directory. That mode offloads the transformer after each image, which conflicts with the folder-processing flow.
+
 ```sh
 mflux-upscale-seedvr2 \
   --image-path "./inputs" \

tests/image_generation/helpers/seedvr2_upscale_test_helper.py

@@ -14,6 +14,7 @@ def assert_matches_reference_image(
         output_image_path: str,
         input_image_path: str,
         *,
+        model_config: ModelConfig | None = None,
         tiling_config: TilingConfig | None = None,
         seed: int = 42,
         resolution: int = 320,
@@ -28,7 +29,7 @@ def assert_matches_reference_image(
             model = SeedVR2(
                 quantize=quantize,
                 model_path=None,
-                model_config=ModelConfig.seedvr2_3b(),
+                model_config=model_config or ModelConfig.seedvr2_3b(),
             )
             if tiling_config is not None:
                 model.tiling_config = tiling_config

tests/image_generation/test_generate_image_seedvr2_upscale.py

@@ -1,5 +1,6 @@
 import pytest
 
+from mflux.models.common.config.model_config import ModelConfig
 from tests.image_generation.helpers.seedvr2_upscale_test_helper import SeedVR2UpscaleTestHelper
 
 
@@ -14,3 +15,15 @@ def test_seedvr2_upscale(self):
             resolution=1080,
             quantize=8,
         )
+
+    @pytest.mark.slow
+    def test_seedvr2_7b_upscale(self):
+        SeedVR2UpscaleTestHelper.assert_matches_reference_image(
+            reference_image_path="reference_seedvr2_7b_upscaled.png",
+            output_image_path="output_seedvr2_7b_upscaled.png",
+            input_image_path="reference_z_image_turbo_lora.png",
+            model_config=ModelConfig.seedvr2_7b(),
+            seed=42,
+            resolution=1080,
+            quantize=8,
+        )