def encode_np_array()

in src/datasets/features/image.py [0:0]

• 35 lines of code
• 10 McCabe index (conditional complexity)

def encode_np_array(array: np.ndarray) -> dict:
    if config.PIL_AVAILABLE:
        import PIL.Image
    else:
        raise ImportError("To support encoding images, please install 'Pillow'.")

    dtype = array.dtype
    dtype_byteorder = dtype.byteorder if dtype.byteorder != "=" else _NATIVE_BYTEORDER
    dtype_kind = dtype.kind
    dtype_itemsize = dtype.itemsize

    dest_dtype = None

    # Multi-channel array case (only np.dtype("|u1") is allowed)
    if array.shape[2:]:
        if dtype_kind not in ["u", "i"]:
            raise TypeError(
                f"Unsupported array dtype {dtype} for image encoding. Only {dest_dtype} is supported for multi-channel arrays."
            )
        dest_dtype = np.dtype("|u1")
        if dtype != dest_dtype:
            warnings.warn(f"Downcasting array dtype {dtype} to {dest_dtype} to be compatible with 'Pillow'")
    # Exact match
    elif dtype in _VALID_IMAGE_ARRAY_DTPYES:
        dest_dtype = dtype
    else:  # Downcast the type within the kind (np.can_cast(from_type, to_type, casting="same_kind") doesn't behave as expected, so do it manually)
        while dtype_itemsize >= 1:
            dtype_str = dtype_byteorder + dtype_kind + str(dtype_itemsize)
            if np.dtype(dtype_str) in _VALID_IMAGE_ARRAY_DTPYES:
                dest_dtype = np.dtype(dtype_str)
                warnings.warn(f"Downcasting array dtype {dtype} to {dest_dtype} to be compatible with 'Pillow'")
                break
            else:
                dtype_itemsize //= 2
        if dest_dtype is None:
            raise TypeError(
                f"Cannot downcast dtype {dtype} to a valid image dtype. Valid image dtypes: {_VALID_IMAGE_ARRAY_DTPYES}"
            )

    image = PIL.Image.fromarray(array.astype(dest_dtype))
    return {"path": None, "bytes": image_to_bytes(image)}