refactor(compressors): reorganize SAM utilities into proposal module

mini-nav/compressors/proposal/utils.py

@@ -0,0 +1,25 @@
+"""Mask extraction utilities."""
+
+import numpy as np
+from PIL import Image
+
+
+def extract_masked_region(
+    image: Image.Image,
+    mask: np.ndarray,
+) -> Image.Image:
+    """Extract masked region from image.
+
+    Args:
+        image: Original PIL Image.
+        mask: Binary mask as numpy array (True = keep).
+
+    Returns:
+        PIL Image with only the masked region visible.
+    """
+    image_np = np.array(image.convert("RGB"))
+
+    # Apply mask.
+    masked_np = image_np * mask[:, :, np.newaxis]
+
+    return Image.fromarray(masked_np.astype(np.uint8))