from helper import unittest, PillowTestCase, tearDownModule, lena from PIL import Image class TestImageTransform(PillowTestCase): def test_extent(self): im = lena('RGB') (w, h) = im.size transformed = im.transform(im.size, Image.EXTENT, (0, 0, w//2, h//2), # ul -> lr Image.BILINEAR) scaled = im.resize((w*2, h*2), Image.BILINEAR).crop((0, 0, w, h)) # undone -- precision? self.assert_image_similar(transformed, scaled, 10) def test_quad(self): # one simple quad transform, equivalent to scale & crop upper left quad im = lena('RGB') (w, h) = im.size transformed = im.transform(im.size, Image.QUAD, (0, 0, 0, h//2, # ul -> ccw around quad: w//2, h//2, w//2, 0), Image.BILINEAR) scaled = im.resize((w*2, h*2), Image.BILINEAR).crop((0, 0, w, h)) self.assert_image_equal(transformed, scaled) def test_mesh(self): # this should be a checkerboard of halfsized lenas in ul, lr im = lena('RGBA') (w, h) = im.size transformed = im.transform(im.size, Image.MESH, [((0, 0, w//2, h//2), # box (0, 0, 0, h, w, h, w, 0)), # ul -> ccw around quad ((w//2, h//2, w, h), # box (0, 0, 0, h, w, h, w, 0))], # ul -> ccw around quad Image.BILINEAR) # transformed.save('transformed.png') scaled = im.resize((w//2, h//2), Image.BILINEAR) checker = Image.new('RGBA', im.size) checker.paste(scaled, (0, 0)) checker.paste(scaled, (w//2, h//2)) self.assert_image_equal(transformed, checker) # now, check to see that the extra area is (0, 0, 0, 0) blank = Image.new('RGBA', (w//2, h//2), (0, 0, 0, 0)) self.assert_image_equal(blank, transformed.crop((w//2, 0, w, h//2))) self.assert_image_equal(blank, transformed.crop((0, h//2, w//2, h))) def _test_alpha_premult(self, op): # create image with half white, half black, # with the black half transparent. # do op, # there should be no darkness in the white section. im = Image.new('RGBA', (10, 10), (0, 0, 0, 0)) im2 = Image.new('RGBA', (5, 10), (255, 255, 255, 255)) im.paste(im2, (0, 0)) im = op(im, (40, 10)) im_background = Image.new('RGB', (40, 10), (255, 255, 255)) im_background.paste(im, (0, 0), im) hist = im_background.histogram() self.assertEqual(40*10, hist[-1]) def test_alpha_premult_resize(self): def op(im, sz): return im.resize(sz, Image.LINEAR) self._test_alpha_premult(op) def test_alpha_premult_transform(self): def op(im, sz): (w, h) = im.size return im.transform(sz, Image.EXTENT, (0, 0, w, h), Image.BILINEAR) self._test_alpha_premult(op) def test_blank_fill(self): # attempting to hit # https://github.com/python-pillow/Pillow/issues/254 reported # # issue is that transforms with transparent overflow area # contained junk from previous images, especially on systems with # constrained memory. So, attempt to fill up memory with a # pattern, free it, and then run the mesh test again. Using a 1Mp # image with 4 bands, for 4 megs of data allocated, x 64. OMM (64 # bit 12.04 VM with 512 megs available, this fails with Pillow < # a0eaf06cc5f62a6fb6de556989ac1014ff3348ea # # Running by default, but I'd totally understand not doing it in # the future foo = [ Image.new('RGBA', (1024, 1024), (a, a, a, a)) for a in range(1, 65)] # Yeah. Watch some JIT optimize this out. foo = None self.test_mesh() if __name__ == '__main__': unittest.main() # End of file