[Image-SIG] Bug in rotate with expand=True

Ole Laursen olau at iola.dk
Fri Apr 4 11:31:03 CEST 2008


Hi,

Try this

import Image, ImageDraw

i = Image.new("RGBA", (100, 100), (255, 0, 0, 0))
draw = ImageDraw.Draw(i)
draw.line([(0, 50), (100, 50)], fill=(255, 0, 0), width=3)
i.save("original.png")

i.rotate(15, Image.BICUBIC, True).save("enlarged.png")
i.rotate(15, Image.BICUBIC, False).save("not-enlarged.png")

Then take a look at "enlarged.png". Contrary to "not-enlarged.png",
it's not anti-aliased in spite of both having Image.BICUBIC set. I
believe this is a bug in rotate(). It appears to be a question of line
1320 in Image.py

            return self.transform((w, h), AFFINE, matrix)

missing the resample parameter

            return self.transform((w, h), AFFINE, matrix, resample)


(Please keep the CC as I'm not subscribed to the list.)

-- 
Ole Laursen
http://www.iola.dk/


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