def image_batch(request, channels_first):
    """
    Image fixtures of shape NHWC and NCHW.
    """
    channels = request.param
    image_input = DataGenerator(channels_first, channels)
    test_input = image_input.get_data()
    test_output = test_input.copy()
    return test_input, test_output

    Image fixtures of shape NHWC and NCHW.
    
tests/defences/preprocessor/test_jpeg_compression.py