substitute for imsubtract

if a = np.array([ [255,10,75], [44, 225, 100]], dtype=np.uint8) b = np.array([ [50, 50, 50],[50, 50, 50] ], dtype=np.uint8) can (a.astype(int) - b.astype(int)).clip(0, 255) be good substitute for imsubtract function? If so or not so, is there a need to have this kind of function in skimage library?