feat: pack uint8 BGR non-planar format images

Author: anna-singleton-resolver

.gitignore

@@ -8,7 +8,7 @@ wheels/
 
 # Virtual environments
 .venv
-.env
+.env*
 
 docs/_build/
 

src/resolver_athena_client/client/transformers/core.py

@@ -19,7 +19,7 @@
 _expected_raw_size = EXPECTED_WIDTH * EXPECTED_HEIGHT * 3
 
 
-def _is_raw_rgb_expected_size(data: bytes) -> bool:
+def _is_raw_brg_expected_size(data: bytes) -> bool:
     """Detect if data is already a raw RGB array of expected size."""
     return len(data) == _expected_raw_size
 
@@ -37,7 +37,7 @@ async def resize_image(image_data: ImageData) -> ImageData:
 
     def process_image() -> tuple[bytes, bool]:
         # Fast path for raw RGB arrays of correct size
-        if _is_raw_rgb_expected_size(image_data.data):
+        if _is_raw_brg_expected_size(image_data.data):
             return image_data.data, False  # No transformation needed
 
         # Try to load the image data directly
@@ -55,8 +55,17 @@ def process_image() -> tuple[bytes, bool]:
             else:
                 resized_image = rgb_image
 
-            # Convert to raw RGB bytes (C-order: height x width x channels)
-            return resized_image.tobytes(), True  # Data was transformed
+            rgb_bytes = resized_image.tobytes()
+
+            # Convert RGB to BGR by swapping channels
+            brg_bytes = bytearray(len(rgb_bytes))
+            brg_bytes[:] = rgb_bytes  # Initialize with RGB data
+
+            for i in range(0, len(rgb_bytes), 3):
+                brg_bytes[i] = rgb_bytes[i + 2]     # B
+                brg_bytes[i + 2] = rgb_bytes[i]     # R
+
+            return bytes(brg_bytes), True  # Data was transformed
 
     # Use thread pool for CPU-intensive processing
     resized_bytes, was_transformed = await asyncio.to_thread(process_image)