from __future__ import annotations from typing import Generator import pytest from PIL import Image, ImageFilter @pytest.fixture def test_images() -> Generator[dict[str, Image.Image], None, None]: ims = { "im": Image.open("Tests/images/hopper.ppm"), "snakes": Image.open("Tests/images/color_snakes.png"), } try: yield ims finally: for im in ims.values(): im.close() def test_filter_api(test_images: dict[str, Image.Image]) -> None: im = test_images["im"] test_filter = ImageFilter.GaussianBlur(2.0) i = im.filter(test_filter) assert i.mode == "RGB" assert i.size == (128, 128) test_filter2 = ImageFilter.UnsharpMask(2.0, 125, 8) i = im.filter(test_filter2) assert i.mode == "RGB" assert i.size == (128, 128) def test_usm_formats(test_images: dict[str, Image.Image]) -> None: im = test_images["im"] usm = ImageFilter.UnsharpMask with pytest.raises(ValueError): im.convert("1").filter(usm) im.convert("L").filter(usm) with pytest.raises(ValueError): im.convert("I").filter(usm) with pytest.raises(ValueError): im.convert("F").filter(usm) im.convert("RGB").filter(usm) im.convert("RGBA").filter(usm) im.convert("CMYK").filter(usm) with pytest.raises(ValueError): im.convert("YCbCr").filter(usm) def test_blur_formats(test_images: dict[str, Image.Image]) -> None: im = test_images["im"] blur = ImageFilter.GaussianBlur with pytest.raises(ValueError): im.convert("1").filter(blur) blur(im.convert("L")) with pytest.raises(ValueError): im.convert("I").filter(blur) with pytest.raises(ValueError): im.convert("F").filter(blur) im.convert("RGB").filter(blur) im.convert("RGBA").filter(blur) im.convert("CMYK").filter(blur) with pytest.raises(ValueError): im.convert("YCbCr").filter(blur) def test_usm_accuracy(test_images: dict[str, Image.Image]) -> None: snakes = test_images["snakes"] src = snakes.convert("RGB") i = src.filter(ImageFilter.UnsharpMask(5, 1024, 0)) # Image should not be changed because it have only 0 and 255 levels. assert i.tobytes() == src.tobytes() def test_blur_accuracy(test_images: dict[str, Image.Image]) -> None: snakes = test_images["snakes"] i = snakes.filter(ImageFilter.GaussianBlur(0.4)) # These pixels surrounded with pixels with 255 intensity. # They must be very close to 255. for x, y, c in [ (1, 0, 1), (2, 0, 1), (7, 8, 1), (8, 8, 1), (2, 9, 1), (7, 3, 0), (8, 3, 0), (5, 8, 0), (5, 9, 0), (1, 3, 0), (4, 3, 2), (4, 2, 2), ]: assert i.im.getpixel((x, y))[c] >= 250 # Fuzzy match. def gp(x, y): return i.im.getpixel((x, y)) assert 236 <= gp(7, 4)[0] <= 239 assert 236 <= gp(7, 5)[2] <= 239 assert 236 <= gp(7, 6)[2] <= 239 assert 236 <= gp(7, 7)[1] <= 239 assert 236 <= gp(8, 4)[0] <= 239 assert 236 <= gp(8, 5)[2] <= 239 assert 236 <= gp(8, 6)[2] <= 239 assert 236 <= gp(8, 7)[1] <= 239