Pillow/Tests/test_image_quantize.py
2022-02-19 10:49:23 +11:00

126 lines
3.5 KiB
Python

import pytest
from packaging.version import parse as parse_version
from PIL import Image, features
from .helper import assert_image_similar, hopper, is_ppc64le, skip_unless_feature
def test_sanity():
image = hopper()
converted = image.quantize()
assert converted.mode == "P"
assert_image_similar(converted.convert("RGB"), image, 10)
image = hopper()
converted = image.quantize(palette=hopper("P"))
assert converted.mode == "P"
assert_image_similar(converted.convert("RGB"), image, 60)
@skip_unless_feature("libimagequant")
def test_libimagequant_quantize():
image = hopper()
if is_ppc64le():
libimagequant = parse_version(features.version_feature("libimagequant"))
if libimagequant < parse_version("4"):
pytest.skip("Fails with libimagequant earlier than 4.0.0 on ppc64le")
converted = image.quantize(100, Image.Quantize.LIBIMAGEQUANT)
assert converted.mode == "P"
assert_image_similar(converted.convert("RGB"), image, 15)
assert len(converted.getcolors()) == 100
def test_octree_quantize():
image = hopper()
converted = image.quantize(100, Image.Quantize.FASTOCTREE)
assert converted.mode == "P"
assert_image_similar(converted.convert("RGB"), image, 20)
assert len(converted.getcolors()) == 100
def test_rgba_quantize():
image = hopper("RGBA")
with pytest.raises(ValueError):
image.quantize(method=0)
assert image.quantize().convert().mode == "RGBA"
def test_quantize():
with Image.open("Tests/images/caption_6_33_22.png") as image:
image = image.convert("RGB")
converted = image.quantize()
assert converted.mode == "P"
assert_image_similar(converted.convert("RGB"), image, 1)
def test_quantize_no_dither():
image = hopper()
with Image.open("Tests/images/caption_6_33_22.png") as palette:
palette = palette.convert("P")
converted = image.quantize(dither=Image.Dither.NONE, palette=palette)
assert converted.mode == "P"
assert converted.palette.palette == palette.palette.palette
def test_quantize_dither_diff():
image = hopper()
with Image.open("Tests/images/caption_6_33_22.png") as palette:
palette = palette.convert("P")
dither = image.quantize(dither=Image.Dither.FLOYDSTEINBERG, palette=palette)
nodither = image.quantize(dither=Image.Dither.NONE, palette=palette)
assert dither.tobytes() != nodither.tobytes()
def test_colors():
im = hopper()
colors = 2
converted = im.quantize(colors)
assert len(converted.palette.palette) == colors * len("RGB")
def test_transparent_colors_equal():
im = Image.new("RGBA", (1, 2), (0, 0, 0, 0))
px = im.load()
px[0, 1] = (255, 255, 255, 0)
converted = im.quantize()
converted_px = converted.load()
assert converted_px[0, 0] == converted_px[0, 1]
@pytest.mark.parametrize(
"method, color",
(
(Image.Quantize.MEDIANCUT, (0, 0, 0)),
(Image.Quantize.MAXCOVERAGE, (0, 0, 0)),
(Image.Quantize.FASTOCTREE, (0, 0, 0)),
(Image.Quantize.FASTOCTREE, (0, 0, 0, 0)),
),
)
def test_palette(method, color):
im = Image.new("RGBA" if len(color) == 4 else "RGB", (1, 1), color)
converted = im.quantize(method=method)
converted_px = converted.load()
assert converted_px[0, 0] == converted.palette.colors[color]
def test_small_palette():
# Arrange
im = hopper()
colors = (255, 0, 0, 0, 0, 255)
p = Image.new("P", (1, 1))
p.putpalette(colors)
# Act
im = im.quantize(palette=p)
# Assert
assert len(im.getcolors()) == 2