import pytest from PIL import Image, WebPImagePlugin from .helper import ( assert_image_similar, assert_image_similar_tofile, hopper, skip_unless_feature, ) try: from PIL import _webp HAVE_WEBP = True except ImportError: HAVE_WEBP = False class TestUnsupportedWebp: def test_unsupported(self): if HAVE_WEBP: WebPImagePlugin.SUPPORTED = False file_path = "Tests/images/hopper.webp" pytest.warns(UserWarning, lambda: pytest.raises(IOError, Image.open, file_path)) if HAVE_WEBP: WebPImagePlugin.SUPPORTED = True @skip_unless_feature("webp") class TestFileWebp: def setup_method(self): self.rgb_mode = "RGB" def test_version(self): _webp.WebPDecoderVersion() _webp.WebPDecoderBuggyAlpha() def test_read_rgb(self): """ Can we read a RGB mode WebP file without error? Does it have the bits we expect? """ with Image.open("Tests/images/hopper.webp") as image: assert image.mode == self.rgb_mode assert image.size == (128, 128) assert image.format == "WEBP" image.load() image.getdata() # generated with: # dwebp -ppm ../../Tests/images/hopper.webp -o hopper_webp_bits.ppm assert_image_similar_tofile(image, "Tests/images/hopper_webp_bits.ppm", 1.0) def test_write_rgb(self, tmp_path): """ Can we write a RGB mode file to webp without error. Does it have the bits we expect? """ temp_file = str(tmp_path / "temp.webp") hopper(self.rgb_mode).save(temp_file) with Image.open(temp_file) as image: assert image.mode == self.rgb_mode assert image.size == (128, 128) assert image.format == "WEBP" image.load() image.getdata() # generated with: dwebp -ppm temp.webp -o hopper_webp_write.ppm assert_image_similar_tofile( image, "Tests/images/hopper_webp_write.ppm", 12.0 ) # This test asserts that the images are similar. If the average pixel # difference between the two images is less than the epsilon value, # then we're going to accept that it's a reasonable lossy version of # the image. The old lena images for WebP are showing ~16 on # Ubuntu, the jpegs are showing ~18. target = hopper(self.rgb_mode) assert_image_similar(image, target, 12.0) def test_write_unsupported_mode_L(self, tmp_path): """ Saving a black-and-white file to WebP format should work, and be similar to the original file. """ temp_file = str(tmp_path / "temp.webp") hopper("L").save(temp_file) with Image.open(temp_file) as image: assert image.mode == self.rgb_mode assert image.size == (128, 128) assert image.format == "WEBP" image.load() image.getdata() target = hopper("L").convert(self.rgb_mode) assert_image_similar(image, target, 10.0) def test_write_unsupported_mode_P(self, tmp_path): """ Saving a palette-based file to WebP format should work, and be similar to the original file. """ temp_file = str(tmp_path / "temp.webp") hopper("P").save(temp_file) with Image.open(temp_file) as image: assert image.mode == self.rgb_mode assert image.size == (128, 128) assert image.format == "WEBP" image.load() image.getdata() target = hopper("P").convert(self.rgb_mode) assert_image_similar(image, target, 50.0) def test_WebPEncode_with_invalid_args(self): """ Calling encoder functions with no arguments should result in an error. """ if _webp.HAVE_WEBPANIM: with pytest.raises(TypeError): _webp.WebPAnimEncoder() with pytest.raises(TypeError): _webp.WebPEncode() def test_WebPDecode_with_invalid_args(self): """ Calling decoder functions with no arguments should result in an error. """ if _webp.HAVE_WEBPANIM: with pytest.raises(TypeError): _webp.WebPAnimDecoder() with pytest.raises(TypeError): _webp.WebPDecode() def test_no_resource_warning(self, tmp_path): file_path = "Tests/images/hopper.webp" with Image.open(file_path) as image: temp_file = str(tmp_path / "temp.webp") pytest.warns(None, image.save, temp_file) def test_file_pointer_could_be_reused(self): file_path = "Tests/images/hopper.webp" with open(file_path, "rb") as blob: Image.open(blob).load() Image.open(blob).load() @skip_unless_feature("webp") @skip_unless_feature("webp_anim") def test_background_from_gif(self, tmp_path): with Image.open("Tests/images/chi.gif") as im: original_value = im.convert("RGB").getpixel((1, 1)) # Save as WEBP out_webp = str(tmp_path / "temp.webp") im.save(out_webp, save_all=True) # Save as GIF out_gif = str(tmp_path / "temp.gif") Image.open(out_webp).save(out_gif) with Image.open(out_gif) as reread: reread_value = reread.convert("RGB").getpixel((1, 1)) difference = sum( [abs(original_value[i] - reread_value[i]) for i in range(0, 3)] ) assert difference < 5