conv: Check the input array

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Author: tomba

pixutils/conv/conv.py

@@ -33,7 +33,7 @@ def to_bgr888(
         height: Height of the image in pixels
         bytesperline: Bytes per line, either a single int (0 for no padding) or a
             sequence of ints with one value per plane for multiplane formats
-        arr: Numpy array containing the pixel data
+        arr: Numpy uint8 array containing the pixel data
         options: Optional dictionary with conversion options:
             - backends: List of backends in priority order, e.g. ['opencv', 'numba']
             - range: 'limited' or 'full' (for YUV formats)
@@ -44,6 +44,10 @@ def to_bgr888(
         Numpy array containing the image in BGR888 format
     """
 
+    if arr.dtype != np.uint8:
+        raise ValueError(f'Input array must have dtype uint8, got {arr.dtype}')
+    arr = np.ascontiguousarray(arr).reshape(-1)
+
     # Normalize bytesperline to a per-plane tuple of concrete (non-zero) strides
     if isinstance(bytesperline, int):
         if len(fmt.planes) > 1 and bytesperline != 0: