Pillow/Tests/test_file_gif.py
2017-06-03 14:04:54 +10:00

536 lines
17 KiB
Python

from helper import unittest, PillowTestCase, hopper, netpbm_available
from PIL import Image, ImagePalette, GifImagePlugin
from io import BytesIO
codecs = dir(Image.core)
# sample gif stream
TEST_GIF = "Tests/images/hopper.gif"
with open(TEST_GIF, "rb") as f:
data = f.read()
class TestFileGif(PillowTestCase):
def setUp(self):
if "gif_encoder" not in codecs or "gif_decoder" not in codecs:
self.skipTest("gif support not available") # can this happen?
def test_sanity(self):
im = Image.open(TEST_GIF)
im.load()
self.assertEqual(im.mode, "P")
self.assertEqual(im.size, (128, 128))
self.assertEqual(im.format, "GIF")
self.assertEqual(im.info["version"], b"GIF89a")
def test_invalid_file(self):
invalid_file = "Tests/images/flower.jpg"
self.assertRaises(SyntaxError,
lambda: GifImagePlugin.GifImageFile(invalid_file))
def test_optimize(self):
def test_grayscale(optimize):
im = Image.new("L", (1, 1), 0)
filename = BytesIO()
im.save(filename, "GIF", optimize=optimize)
return len(filename.getvalue())
def test_bilevel(optimize):
im = Image.new("1", (1, 1), 0)
test_file = BytesIO()
im.save(test_file, "GIF", optimize=optimize)
return len(test_file.getvalue())
self.assertEqual(test_grayscale(0), 800)
self.assertEqual(test_grayscale(1), 38)
self.assertEqual(test_bilevel(0), 800)
self.assertEqual(test_bilevel(1), 800)
def test_optimize_correctness(self):
# 256 color Palette image, posterize to > 128 and < 128 levels
# Size bigger and smaller than 512x512
# Check the palette for number of colors allocated.
# Check for correctness after conversion back to RGB
def check(colors, size, expected_palette_length):
# make an image with empty colors in the start of the palette range
im = Image.frombytes('P', (colors, colors),
bytes(bytearray(range(256-colors, 256))*colors))
im = im.resize((size, size))
outfile = BytesIO()
im.save(outfile, 'GIF')
outfile.seek(0)
reloaded = Image.open(outfile)
# check palette length
palette_length = max(i+1 for i, v in enumerate(reloaded.histogram()) if v)
self.assertEqual(expected_palette_length, palette_length)
self.assert_image_equal(im.convert('RGB'), reloaded.convert('RGB'))
# These do optimize the palette
check(128, 511, 128)
check(64, 511, 64)
check(4, 511, 4)
# These don't optimize the palette
check(128, 513, 256)
check(64, 513, 256)
check(4, 513, 256)
# other limits that don't optimize the palette
check(129, 511, 256)
check(255, 511, 256)
check(256, 511, 256)
def test_optimize_full_l(self):
im = Image.frombytes("L", (16, 16), bytes(bytearray(range(256))))
test_file = BytesIO()
im.save(test_file, "GIF", optimize=True)
self.assertEqual(im.mode, "L")
def test_roundtrip(self):
out = self.tempfile('temp.gif')
im = hopper()
im.save(out)
reread = Image.open(out)
self.assert_image_similar(reread.convert('RGB'), im, 50)
def test_roundtrip2(self):
# see https://github.com/python-pillow/Pillow/issues/403
out = self.tempfile('temp.gif')
im = Image.open(TEST_GIF)
im2 = im.copy()
im2.save(out)
reread = Image.open(out)
self.assert_image_similar(reread.convert('RGB'), hopper(), 50)
def test_roundtrip_save_all(self):
# Single frame image
out = self.tempfile('temp.gif')
im = hopper()
im.save(out, save_all=True)
reread = Image.open(out)
self.assert_image_similar(reread.convert('RGB'), im, 50)
# Multiframe image
im = Image.open("Tests/images/dispose_bgnd.gif")
out = self.tempfile('temp.gif')
im.save(out, save_all=True)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 5)
def test_headers_saving_for_animated_gifs(self):
important_headers = ['background', 'version', 'duration', 'loop']
# Multiframe image
im = Image.open("Tests/images/dispose_bgnd.gif")
out = self.tempfile('temp.gif')
im.save(out, save_all=True)
reread = Image.open(out)
for header in important_headers:
self.assertEqual(
im.info[header],
reread.info[header]
)
def test_palette_handling(self):
# see https://github.com/python-pillow/Pillow/issues/513
im = Image.open(TEST_GIF)
im = im.convert('RGB')
im = im.resize((100, 100), Image.LANCZOS)
im2 = im.convert('P', palette=Image.ADAPTIVE, colors=256)
f = self.tempfile('temp.gif')
im2.save(f, optimize=True)
reloaded = Image.open(f)
self.assert_image_similar(im, reloaded.convert('RGB'), 10)
def test_palette_434(self):
# see https://github.com/python-pillow/Pillow/issues/434
def roundtrip(im, *args, **kwargs):
out = self.tempfile('temp.gif')
im.copy().save(out, *args, **kwargs)
reloaded = Image.open(out)
return reloaded
orig = "Tests/images/test.colors.gif"
im = Image.open(orig)
self.assert_image_similar(im, roundtrip(im), 1)
self.assert_image_similar(im, roundtrip(im, optimize=True), 1)
im = im.convert("RGB")
# check automatic P conversion
reloaded = roundtrip(im).convert('RGB')
self.assert_image_equal(im, reloaded)
@unittest.skipUnless(netpbm_available(), "netpbm not available")
def test_save_netpbm_bmp_mode(self):
img = Image.open(TEST_GIF).convert("RGB")
tempfile = self.tempfile("temp.gif")
GifImagePlugin._save_netpbm(img, 0, tempfile)
self.assert_image_similar(img, Image.open(tempfile).convert("RGB"), 0)
@unittest.skipUnless(netpbm_available(), "netpbm not available")
def test_save_netpbm_l_mode(self):
img = Image.open(TEST_GIF).convert("L")
tempfile = self.tempfile("temp.gif")
GifImagePlugin._save_netpbm(img, 0, tempfile)
self.assert_image_similar(img, Image.open(tempfile).convert("L"), 0)
def test_seek(self):
img = Image.open("Tests/images/dispose_none.gif")
framecount = 0
try:
while True:
framecount += 1
img.seek(img.tell() + 1)
except EOFError:
self.assertEqual(framecount, 5)
def test_n_frames(self):
im = Image.open(TEST_GIF)
self.assertEqual(im.n_frames, 1)
self.assertFalse(im.is_animated)
im = Image.open("Tests/images/iss634.gif")
self.assertEqual(im.n_frames, 42)
self.assertTrue(im.is_animated)
def test_eoferror(self):
im = Image.open(TEST_GIF)
n_frames = im.n_frames
while True:
n_frames -= 1
try:
im.seek(n_frames)
break
except EOFError:
self.assertLess(im.tell(), n_frames)
def test_dispose_none(self):
img = Image.open("Tests/images/dispose_none.gif")
try:
while True:
img.seek(img.tell() + 1)
self.assertEqual(img.disposal_method, 1)
except EOFError:
pass
def test_dispose_background(self):
img = Image.open("Tests/images/dispose_bgnd.gif")
try:
while True:
img.seek(img.tell() + 1)
self.assertEqual(img.disposal_method, 2)
except EOFError:
pass
def test_dispose_previous(self):
img = Image.open("Tests/images/dispose_prev.gif")
try:
while True:
img.seek(img.tell() + 1)
self.assertEqual(img.disposal_method, 3)
except EOFError:
pass
def test_iss634(self):
img = Image.open("Tests/images/iss634.gif")
# seek to the second frame
img.seek(img.tell() + 1)
# all transparent pixels should be replaced with the color from the
# first frame
self.assertEqual(img.histogram()[img.info['transparency']], 0)
def test_duration(self):
duration = 1000
out = self.tempfile('temp.gif')
im = Image.new('L', (100, 100), '#000')
im.save(out, duration=duration)
reread = Image.open(out)
self.assertEqual(reread.info['duration'], duration)
def test_multiple_duration(self):
duration_list = [1000, 2000, 3000]
out = self.tempfile('temp.gif')
im_list = [
Image.new('L', (100, 100), '#000'),
Image.new('L', (100, 100), '#111'),
Image.new('L', (100, 100), '#222')
]
# duration as list
im_list[0].save(
out,
save_all=True,
append_images=im_list[1:],
duration=duration_list
)
reread = Image.open(out)
for duration in duration_list:
self.assertEqual(reread.info['duration'], duration)
try:
reread.seek(reread.tell() + 1)
except EOFError:
pass
# duration as tuple
im_list[0].save(
out,
save_all=True,
append_images=im_list[1:],
duration=tuple(duration_list)
)
reread = Image.open(out)
for duration in duration_list:
self.assertEqual(reread.info['duration'], duration)
try:
reread.seek(reread.tell() + 1)
except EOFError:
pass
def test_identical_frames(self):
duration_list = [1000, 1500, 2000, 4000]
out = self.tempfile('temp.gif')
im_list = [
Image.new('L', (100, 100), '#000'),
Image.new('L', (100, 100), '#000'),
Image.new('L', (100, 100), '#000'),
Image.new('L', (100, 100), '#111')
]
# duration as list
im_list[0].save(
out,
save_all=True,
append_images=im_list[1:],
duration=duration_list
)
reread = Image.open(out)
# Assert that the first three frames were combined
self.assertEqual(reread.n_frames, 2)
# Assert that the new duration is the total of the identical frames
self.assertEqual(reread.info['duration'], 4500)
def test_number_of_loops(self):
number_of_loops = 2
out = self.tempfile('temp.gif')
im = Image.new('L', (100, 100), '#000')
im.save(out, loop=number_of_loops)
reread = Image.open(out)
self.assertEqual(reread.info['loop'], number_of_loops)
def test_background(self):
out = self.tempfile('temp.gif')
im = Image.new('L', (100, 100), '#000')
im.info['background'] = 1
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info['background'], im.info['background'])
def test_comment(self):
im = Image.open(TEST_GIF)
self.assertEqual(im.info['comment'], b"File written by Adobe Photoshop\xa8 4.0")
out = self.tempfile('temp.gif')
im = Image.new('L', (100, 100), '#000')
im.info['comment'] = b"Test comment text"
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info['comment'], im.info['comment'])
def test_version(self):
out = self.tempfile('temp.gif')
# Test that GIF87a is used by default
im = Image.new('L', (100, 100), '#000')
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info["version"], b"GIF87a")
# Test that adding a GIF89a feature changes the version
im.info["transparency"] = 1
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info["version"], b"GIF89a")
# Test that a GIF87a image is also saved in that format
im = Image.open("Tests/images/test.colors.gif")
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info["version"], b"GIF87a")
# Test that a GIF89a image is also saved in that format
im.info["version"] = b"GIF89a"
im.save(out)
reread = Image.open(out)
self.assertEqual(reread.info["version"], b"GIF87a")
def test_append_images(self):
out = self.tempfile('temp.gif')
# Test appending single frame images
im = Image.new('RGB', (100, 100), '#f00')
ims = [Image.new('RGB', (100, 100), color) for color in ['#0f0', '#00f']]
im.save(out, save_all=True, append_images=ims)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 3)
# Tests appending single and multiple frame images
im = Image.open("Tests/images/dispose_none.gif")
ims = [Image.open("Tests/images/dispose_prev.gif")]
im.save(out, save_all=True, append_images=ims)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 10)
def test_transparent_optimize(self):
# from issue #2195, if the transparent color is incorrectly
# optimized out, gif loses transparency
# Need a palette that isn't using the 0 color, and one
# that's > 128 items where the transparent color is actually
# the top palette entry to trigger the bug.
from PIL import ImagePalette
data = bytes(bytearray(range(1, 254)))
palette = ImagePalette.ImagePalette("RGB", list(range(256))*3)
im = Image.new('L', (253, 1))
im.frombytes(data)
im.putpalette(palette)
out = self.tempfile('temp.gif')
im.save(out, transparency=253)
reloaded = Image.open(out)
self.assertEqual(reloaded.info['transparency'], 253)
def test_bbox(self):
out = self.tempfile('temp.gif')
im = Image.new('RGB', (100, 100), '#fff')
ims = [Image.new("RGB", (100, 100), '#000')]
im.save(out, save_all=True, append_images=ims)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 2)
def test_palette_save_L(self):
# generate an L mode image with a separate palette
im = hopper('P')
im_l = Image.frombytes('L', im.size, im.tobytes())
palette = bytes(bytearray(im.getpalette()))
out = self.tempfile('temp.gif')
im_l.save(out, palette=palette)
reloaded = Image.open(out)
self.assert_image_equal(reloaded.convert('RGB'), im.convert('RGB'))
def test_palette_save_P(self):
# pass in a different palette, then construct what the image
# would look like.
# Forcing a non-straight grayscale palette.
im = hopper('P')
palette = bytes(bytearray([255-i//3 for i in range(768)]))
out = self.tempfile('temp.gif')
im.save(out, palette=palette)
reloaded = Image.open(out)
im.putpalette(palette)
self.assert_image_equal(reloaded, im)
def test_palette_save_ImagePalette(self):
# pass in a different palette, as an ImagePalette.ImagePalette
# effectively the same as test_palette_save_P
im = hopper('P')
palette = ImagePalette.ImagePalette('RGB', list(range(256))[::-1]*3)
out = self.tempfile('temp.gif')
im.save(out, palette=palette)
reloaded = Image.open(out)
im.putpalette(palette)
self.assert_image_equal(reloaded, im)
def test_save_I(self):
# Test saving something that would trigger the auto-convert to 'L'
im = hopper('I')
out = self.tempfile('temp.gif')
im.save(out)
reloaded = Image.open(out)
self.assert_image_equal(reloaded.convert('L'), im.convert('L'))
def test_getdata(self):
# test getheader/getdata against legacy values
# Create a 'P' image with holes in the palette
im = Image._wedge().resize((16, 16))
im.putpalette(ImagePalette.ImagePalette('RGB'))
im.info = {'background': 0}
passed_palette = bytes(bytearray([255-i//3 for i in range(768)]))
GifImagePlugin._FORCE_OPTIMIZE = True
try:
h = GifImagePlugin.getheader(im, passed_palette)
d = GifImagePlugin.getdata(im)
import pickle
# Enable to get target values on pre-refactor version
# with open('Tests/images/gif_header_data.pkl', 'wb') as f:
# pickle.dump((h, d), f, 1)
with open('Tests/images/gif_header_data.pkl', 'rb') as f:
(h_target, d_target) = pickle.load(f)
self.assertEqual(h, h_target)
self.assertEqual(d, d_target)
finally:
GifImagePlugin._FORCE_OPTIMIZE = False
if __name__ == '__main__':
unittest.main()