update

sorghum_pipeline/data/preprocessor.py

@@ -26,7 +26,11 @@ class ImagePreprocessor:
         """Process 4-band to composite + spectral."""
         d = pil_img.size[0] // 2
         boxes = [(j, i, j + d, i + d) for i, j in product(range(0, pil_img.height, d), range(0, pil_img.width, d))]
-        stack = np.stack([np.array(pil_img.crop(box), dtype=float) for box in boxes], axis=-1)
+        # Convert each quadrant crop to grayscale to ensure 2D per band
+        stack = np.stack([
+            np.array(pil_img.crop(box).convert('L'), dtype=float)
+            for box in boxes
+        ], axis=-1)
         
         # Split into 4 bands and squeeze the extra dimension
         green, red, red_edge, nir = [band.squeeze(-1) for band in np.split(stack, 4, axis=-1)]