Pillow/Tests/test_file_webp.py
Jon Dufresne 4de5477b61 Remove unnecessary unittest.main() boilerplate from test files
With the introduction and use of pytest, it is simple and easy to
execute specific tests in isolation through documented command line
arguments. Either by specifying the module path or through the `-k
EXPRESSION` argument. There is no longer any need to provide the
boilerplate:

    if __name__ == '__main__':
        unittest.main()

To every test file. It is simply noise.

The pattern remains in test files that aren't named with `test_*` as
those files are not discovered and executed by pytest by default.
2019-02-03 10:10:16 -08:00

175 lines
5.4 KiB
Python

from .helper import unittest, PillowTestCase, hopper
from PIL import Image, WebPImagePlugin
try:
from PIL import _webp
HAVE_WEBP = True
except ImportError:
HAVE_WEBP = False
class TestUnsupportedWebp(PillowTestCase):
def test_unsupported(self):
if HAVE_WEBP:
WebPImagePlugin.SUPPORTED = False
file_path = "Tests/images/hopper.webp"
self.assert_warning(
UserWarning,
lambda: self.assertRaises(IOError, Image.open, file_path)
)
if HAVE_WEBP:
WebPImagePlugin.SUPPORTED = True
@unittest.skipIf(not HAVE_WEBP, "WebP support not installed")
class TestFileWebp(PillowTestCase):
def setUp(self):
self.rgb_mode = "RGB"
def test_version(self):
_webp.WebPDecoderVersion()
_webp.WebPDecoderBuggyAlpha()
def test_read_rgb(self):
"""
Can we read a RGB mode WebP file without error?
Does it have the bits we expect?
"""
image = Image.open("Tests/images/hopper.webp")
self.assertEqual(image.mode, self.rgb_mode)
self.assertEqual(image.size, (128, 128))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
# generated with:
# dwebp -ppm ../../Tests/images/hopper.webp -o hopper_webp_bits.ppm
self.assert_image_similar_tofile(
image, 'Tests/images/hopper_webp_bits.ppm', 1.0)
def test_write_rgb(self):
"""
Can we write a RGB mode file to webp without error.
Does it have the bits we expect?
"""
temp_file = self.tempfile("temp.webp")
hopper(self.rgb_mode).save(temp_file)
image = Image.open(temp_file)
self.assertEqual(image.mode, self.rgb_mode)
self.assertEqual(image.size, (128, 128))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
# generated with: dwebp -ppm temp.webp -o hopper_webp_write.ppm
self.assert_image_similar_tofile(
image, 'Tests/images/hopper_webp_write.ppm', 12.0)
# This test asserts that the images are similar. If the average pixel
# difference between the two images is less than the epsilon value,
# then we're going to accept that it's a reasonable lossy version of
# the image. The old lena images for WebP are showing ~16 on
# Ubuntu, the jpegs are showing ~18.
target = hopper(self.rgb_mode)
self.assert_image_similar(image, target, 12.0)
def test_write_unsupported_mode_L(self):
"""
Saving a black-and-white file to WebP format should work, and be
similar to the original file.
"""
temp_file = self.tempfile("temp.webp")
hopper("L").save(temp_file)
image = Image.open(temp_file)
self.assertEqual(image.mode, self.rgb_mode)
self.assertEqual(image.size, (128, 128))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
target = hopper("L").convert(self.rgb_mode)
self.assert_image_similar(image, target, 10.0)
def test_write_unsupported_mode_P(self):
"""
Saving a palette-based file to WebP format should work, and be
similar to the original file.
"""
temp_file = self.tempfile("temp.webp")
hopper("P").save(temp_file)
image = Image.open(temp_file)
self.assertEqual(image.mode, self.rgb_mode)
self.assertEqual(image.size, (128, 128))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
target = hopper("P").convert(self.rgb_mode)
self.assert_image_similar(image, target, 50.0)
def test_WebPEncode_with_invalid_args(self):
"""
Calling encoder functions with no arguments should result in an error.
"""
if _webp.HAVE_WEBPANIM:
self.assertRaises(TypeError, _webp.WebPAnimEncoder)
self.assertRaises(TypeError, _webp.WebPEncode)
def test_WebPDecode_with_invalid_args(self):
"""
Calling decoder functions with no arguments should result in an error.
"""
if _webp.HAVE_WEBPANIM:
self.assertRaises(TypeError, _webp.WebPAnimDecoder)
self.assertRaises(TypeError, _webp.WebPDecode)
def test_no_resource_warning(self):
file_path = "Tests/images/hopper.webp"
image = Image.open(file_path)
temp_file = self.tempfile("temp.webp")
self.assert_warning(None, image.save, temp_file)
def test_file_pointer_could_be_reused(self):
file_path = "Tests/images/hopper.webp"
with open(file_path, 'rb') as blob:
Image.open(blob).load()
Image.open(blob).load()
@unittest.skipUnless(HAVE_WEBP and _webp.HAVE_WEBPANIM,
"WebP save all not available")
def test_background_from_gif(self):
im = Image.open("Tests/images/chi.gif")
original_value = im.convert("RGB").getpixel((1, 1))
# Save as WEBP
out_webp = self.tempfile("temp.webp")
im.save(out_webp, save_all=True)
# Save as GIF
out_gif = self.tempfile("temp.gif")
Image.open(out_webp).save(out_gif)
reread = Image.open(out_gif)
reread_value = reread.convert("RGB").getpixel((1, 1))
difference = sum([abs(original_value[i] - reread_value[i])
for i in range(0, 3)])
self.assertLess(difference, 5)