Pillow/Tests/test_file_jpeg.py

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from tester import *
from PIL import Image
from PIL import ImageFile
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 = BytesIO()
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", b"JFIF\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00"))
assert_equal(im.applist[1], ("COM", b"Python Imaging Library"))
assert_equal(len(im.applist), 2)
def test_cmyk():
# Test CMYK handling. Thanks to Tim and Charlie for test data,
# Michael for getting me to look one more time.
file = "Tests/images/pil_sample_cmyk.jpg"
im = Image.open(file)
# the source image has red pixels in the upper left corner.
c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))]
assert_true(c == 0.0 and m > 0.8 and y > 0.8 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 == 0.0 and m > 0.8 and y > 0.8 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_icc():
# Test ICC support
im1 = Image.open("Tests/images/rgb.jpg")
icc_profile = im1.info["icc_profile"]
assert_equal(len(icc_profile), 3144)
# Roundtrip via physical file.
file = tempfile("temp.jpg")
im1.save(file, icc_profile=icc_profile)
im2 = Image.open(file)
assert_equal(im2.info.get("icc_profile"), icc_profile)
# Roundtrip via memory buffer.
im1 = roundtrip(lena())
im2 = roundtrip(lena(), icc_profile=icc_profile)
assert_image_equal(im1, im2)
assert_false(im1.info.get("icc_profile"))
assert_true(im2.info.get("icc_profile"))
def test_icc_big():
# Make sure that the "extra" support handles large blocks
def test(n):
# The ICC APP marker can store 65519 bytes per marker, so
# using a 4-byte test code should allow us to detect out of
# order issues.
icc_profile = (b"Test"*int(n/4+1))[:n]
assert len(icc_profile) == n # sanity
im1 = roundtrip(lena(), icc_profile=icc_profile)
assert_equal(im1.info.get("icc_profile"), icc_profile or None)
test(0); test(1)
test(3); test(4); test(5)
test(65533-14) # full JPEG marker block
test(65533-14+1) # full block plus one byte
test(ImageFile.MAXBLOCK) # full buffer block
test(ImageFile.MAXBLOCK+1) # full buffer block plus one byte
test(ImageFile.MAXBLOCK*4+3) # large block
def test_optimize():
im1 = roundtrip(lena())
im2 = roundtrip(lena(), optimize=1)
assert_image_equal(im1, im2)
assert_true(im1.bytes >= im2.bytes)
def test_optimize_large_buffer():
#https://github.com/python-imaging/Pillow/issues/148
f = tempfile('temp.jpg')
# this requires ~ 1.5x Image.MAXBLOCK
im = Image.new("RGB", (4096,4096), 0xff3333)
im.save(f, format="JPEG", optimize=True)
def test_large_exif():
#https://github.com/python-imaging/Pillow/issues/148
f = tempfile('temp.jpg')
im = lena()
im.save(f,'JPEG', quality=90, exif=b"1"*65532)
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_exif():
im = Image.open("Tests/images/pil_sample_rgb.jpg")
info = im._getexif()
assert_equal(info[305], 'Adobe Photoshop CS Macintosh')