Pillow/Tests/test_file_webp_alpha.py
Jon Dufresne d50445ff30 Introduce isort to automate import ordering and formatting
Similar to the recent adoption of Black. isort is a Python utility to
sort imports alphabetically and automatically separate into sections. By
using isort, contributors can quickly and automatically conform to the
projects style without thinking. Just let the tool do it.

Uses the configuration recommended by the Black to avoid conflicts of
style.

Rewrite TestImageQt.test_deprecated to no rely on import order.
2019-07-06 16:11:35 -07:00

118 lines
3.4 KiB
Python

from PIL import Image
from .helper import PillowTestCase, hopper, unittest
try:
from PIL import _webp
except ImportError:
_webp = None
@unittest.skipIf(_webp is None, "WebP support not installed")
class TestFileWebpAlpha(PillowTestCase):
def setUp(self):
if _webp.WebPDecoderBuggyAlpha(self):
self.skipTest(
"Buggy early version of WebP installed, not testing transparency"
)
def test_read_rgba(self):
"""
Can we read an RGBA mode file without error?
Does it have the bits we expect?
"""
# Generated with `cwebp transparent.png -o transparent.webp`
file_path = "Tests/images/transparent.webp"
image = Image.open(file_path)
self.assertEqual(image.mode, "RGBA")
self.assertEqual(image.size, (200, 150))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
image.tobytes()
target = Image.open("Tests/images/transparent.png")
self.assert_image_similar(image, target, 20.0)
def test_write_lossless_rgb(self):
"""
Can we write an RGBA mode file with lossless compression without
error? Does it have the bits we expect?
"""
temp_file = self.tempfile("temp.webp")
# temp_file = "temp.webp"
pil_image = hopper("RGBA")
mask = Image.new("RGBA", (64, 64), (128, 128, 128, 128))
# Add some partially transparent bits:
pil_image.paste(mask, (0, 0), mask)
pil_image.save(temp_file, lossless=True)
image = Image.open(temp_file)
image.load()
self.assertEqual(image.mode, "RGBA")
self.assertEqual(image.size, pil_image.size)
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
self.assert_image_equal(image, pil_image)
def test_write_rgba(self):
"""
Can we write a RGBA mode file to webp without error.
Does it have the bits we expect?
"""
temp_file = self.tempfile("temp.webp")
pil_image = Image.new("RGBA", (10, 10), (255, 0, 0, 20))
pil_image.save(temp_file)
if _webp.WebPDecoderBuggyAlpha(self):
return
image = Image.open(temp_file)
image.load()
self.assertEqual(image.mode, "RGBA")
self.assertEqual(image.size, (10, 10))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
# early versions of webp are known to produce higher deviations:
# deal with it
if _webp.WebPDecoderVersion(self) <= 0x201:
self.assert_image_similar(image, pil_image, 3.0)
else:
self.assert_image_similar(image, pil_image, 1.0)
def test_write_unsupported_mode_PA(self):
"""
Saving a palette-based file with transparency to WebP format
should work, and be similar to the original file.
"""
temp_file = self.tempfile("temp.webp")
file_path = "Tests/images/transparent.gif"
Image.open(file_path).save(temp_file)
image = Image.open(temp_file)
self.assertEqual(image.mode, "RGBA")
self.assertEqual(image.size, (200, 150))
self.assertEqual(image.format, "WEBP")
image.load()
image.getdata()
target = Image.open(file_path).convert("RGBA")
self.assert_image_similar(image, target, 25.0)