Fixing grayscale conversion

src/utils/image.py

@@ -289,3 +289,40 @@ class Image:
     def __str__(self) -> str:
         """String representation of the Image object."""
         return self.__repr__()
+
+
+def convert_grayscale_to_rgb_preserve_range(
+    pil_image: PILImage.Image,
+) -> PILImage.Image:
+    """Convert a single-channel PIL image to RGB while preserving dynamic range.
+
+    Args:
+        pil_image: Single-channel PIL image (e.g., 16-bit grayscale).
+
+    Returns:
+        PIL Image in RGB mode with intensities normalized to 0-255.
+    """
+
+    if pil_image.mode == "RGB":
+        return pil_image
+
+    grayscale = np.array(pil_image)
+    if grayscale.ndim == 3:
+        grayscale = grayscale[:, :, 0]
+
+    original_dtype = grayscale.dtype
+    grayscale = grayscale.astype(np.float32)
+
+    if grayscale.size == 0:
+        return PILImage.new("RGB", pil_image.size, color=(0, 0, 0))
+
+    if np.issubdtype(original_dtype, np.integer):
+        denom = float(max(np.iinfo(original_dtype).max, 1))
+    else:
+        max_val = float(grayscale.max())
+        denom = max(max_val, 1.0)
+
+    grayscale = np.clip(grayscale / denom, 0.0, 1.0)
+    grayscale_u8 = (grayscale * 255.0).round().astype(np.uint8)
+    rgb_arr = np.repeat(grayscale_u8[:, :, None], 3, axis=2)
+    return PILImage.fromarray(rgb_arr, mode="RGB")