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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def gen_image(img, width, height, outfile, img_type='grey'):
 """Save an image with the given parameters."""

    assert len(img) == width * height or len(img) == width * height * 3

    if img_type == 'grey':
        misc.imsave(outfile, img.reshape(width, height))

    elif img_type == 'color':
        misc.imsave(outfile, img.reshape(3, width, height))