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Don't show this againpil-2009-raclette / Tests / test_file_jpeg.py
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | from tester import *
from PIL import Image
codecs = dir(Image.core)
if "jpeg_encoder" not in codecs or "jpeg_decoder" not in codecs:
skip("jpeg support not available")
# sample jpeg stream
file = "Images/lena.jpg"
data = open(file, "rb").read()
def roundtrip(im, **options):
out = StringIO()
im.save(out, "JPEG", **options)
bytes = out.tell()
out.seek(0)
im = Image.open(out)
im.bytes = bytes # for testing only
return im
# --------------------------------------------------------------------
def test_sanity():
# internal version number
assert_match(Image.core.jpeglib_version, "\d+\.\d+$")
im = Image.open(file)
im.load()
assert_equal(im.mode, "RGB")
assert_equal(im.size, (128, 128))
assert_equal(im.format, "JPEG")
# --------------------------------------------------------------------
def test_app():
# Test APP/COM reader (@PIL135)
im = Image.open(file)
assert_equal(im.applist[0],
("APP0", "JFIF\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00"))
assert_equal(im.applist[1], ("COM", "Python Imaging Library"))
assert_equal(len(im.applist), 2)
def test_cmyk():
# Test CMYK handling. Thanks to Tim and Charlie for test data.
file = "Tests/images/pil_sample_cmyk.jpg"
im = Image.open(file)
# the source image has red pixels in the upper left corner. with
# the default color profile, that gives us medium cyan/magenta and
# plenty of yellow. don't ask.
c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))]
assert_true(c < 0.4 and m < 0.4 and y > 0.9 and k == 0.0)
# the opposite corner is black
c, m, y, k = [x / 255.0 for x in im.getpixel((im.size[0]-1, im.size[1]-1))]
assert_true(k > 0.9)
# roundtrip, and check again
im = roundtrip(im)
c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))]
assert_true(c > 0.3 and m > 0.3 and y > 0.9 and k == 0.0)
c, m, y, k = [x / 255.0 for x in im.getpixel((im.size[0]-1, im.size[1]-1))]
assert_true(k > 0.9)
def test_dpi():
def test(xdpi, ydpi=None):
im = Image.open(file)
im = roundtrip(im, dpi=(xdpi, ydpi or xdpi))
return im.info.get("dpi")
assert_equal(test(72), (72, 72))
assert_equal(test(300), (300, 300))
assert_equal(test(100, 200), (100, 200))
assert_equal(test(0), None) # square pixels
def test_optimize():
im1 = roundtrip(lena())
im2 = roundtrip(lena(), optimize=1)
assert_image_equal(im1, im2)
assert_true(im1.bytes >= im2.bytes)
def test_progressive():
im1 = roundtrip(lena())
im2 = roundtrip(lena(), progressive=1)
im3 = roundtrip(lena(), progression=1) # compatibility
assert_image_equal(im1, im2)
assert_image_equal(im1, im3)
assert_false(im1.info.get("progressive"))
assert_false(im1.info.get("progression"))
assert_true(im2.info.get("progressive"))
assert_true(im2.info.get("progression"))
assert_true(im3.info.get("progressive"))
assert_true(im3.info.get("progression"))
def test_quality():
im1 = roundtrip(lena())
im2 = roundtrip(lena(), quality=50)
assert_image(im1, im2.mode, im2.size)
assert_true(im1.bytes >= im2.bytes)
def test_smooth():
im1 = roundtrip(lena())
im2 = roundtrip(lena(), smooth=100)
assert_image(im1, im2.mode, im2.size)
def test_subsampling():
def getsampling(im):
layer = im.layer
return layer[0][1:3] + layer[1][1:3] + layer[2][1:3]
# experimental API
im = roundtrip(lena(), subsampling=-1) # default
assert_equal(getsampling(im), (2, 2, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling=0) # 4:4:4
assert_equal(getsampling(im), (1, 1, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling=1) # 4:2:2
assert_equal(getsampling(im), (2, 1, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling=2) # 4:1:1
assert_equal(getsampling(im), (2, 2, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling=3) # default (undefined)
assert_equal(getsampling(im), (2, 2, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling="4:4:4")
assert_equal(getsampling(im), (1, 1, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling="4:2:2")
assert_equal(getsampling(im), (2, 1, 1, 1, 1, 1))
im = roundtrip(lena(), subsampling="4:1:1")
assert_equal(getsampling(im), (2, 2, 1, 1, 1, 1))
assert_exception(TypeError, lambda: roundtrip(lena(), subsampling="1:1:1"))
def test_truncated_jpeg():
def test(junk):
if junk:
# replace "junk" bytes at the end with junk
file = StringIO(data[:-junk] + (junk*chr(0)))
else:
file = StringIO(data)
im = Image.open(file)
im.load()
assert_no_exception(lambda: test(0))
assert_exception(IOError, lambda: test(1))
assert_no_exception(lambda: test(2))
assert_no_exception(lambda: test(4))
assert_no_exception(lambda: test(8))
assert_exception(IOError, lambda: test(10))
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