Pillow/Tests/test_image_transform.py
2013-09-30 22:47:22 -07:00

83 lines
2.8 KiB
Python

from tester import *
from PIL import Image
def test_extent():
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))
assert_image_similar(transformed, scaled, 10) # undone -- precision?
def test_quad():
# 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,
w//2,h//2,w//2,0), # ul -> ccw around quad
Image.BILINEAR)
scaled = im.resize((w*2, h*2), Image.BILINEAR).crop((0,0,w,h))
assert_image_equal(transformed, scaled)
def test_mesh():
# 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))
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))
assert_image_equal(blank, transformed.crop((w//2,0,w,h//2)))
assert_image_equal(blank, transformed.crop((0,h//2,w//2,h)))
def test_blank_fill():
# attempting to hit
# https://github.com/python-imaging/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
test_mesh()