from PIL import Image, ImageEnhance from .helper import assert_image_equal, hopper def test_sanity(): # FIXME: assert_image # Implicit asserts no exception: ImageEnhance.Color(hopper()).enhance(0.5) ImageEnhance.Contrast(hopper()).enhance(0.5) ImageEnhance.Brightness(hopper()).enhance(0.5) ImageEnhance.Sharpness(hopper()).enhance(0.5) def test_crash(): # crashes on small images im = Image.new("RGB", (1, 1)) ImageEnhance.Sharpness(im).enhance(0.5) def _half_transparent_image(): # returns an image, half transparent, half solid im = hopper("RGB") transparent = Image.new("L", im.size, 0) solid = Image.new("L", (im.size[0] // 2, im.size[1]), 255) transparent.paste(solid, (0, 0)) im.putalpha(transparent) return im def _check_alpha(im, original, op, amount): assert im.getbands() == original.getbands() assert_image_equal( im.getchannel("A"), original.getchannel("A"), f"Diff on {op}: {amount}", ) def test_alpha(): # Issue https://github.com/python-pillow/Pillow/issues/899 # Is alpha preserved through image enhancement? original = _half_transparent_image() for op in ["Color", "Brightness", "Contrast", "Sharpness"]: for amount in [0, 0.5, 1.0]: _check_alpha( getattr(ImageEnhance, op)(original).enhance(amount), original, op, amount, )