Pillow/Tests/test_imagepalette.py
Hugo van Kemenade 53c3cd9f8e isort Tests
2024-01-20 13:23:03 +02:00

199 lines
4.8 KiB
Python

from __future__ import annotations
import pytest
from PIL import Image, ImagePalette
from .helper import assert_image_equal, assert_image_equal_tofile
def test_sanity():
palette = ImagePalette.ImagePalette("RGB", list(range(256)) * 3)
assert len(palette.colors) == 256
def test_reload():
with Image.open("Tests/images/hopper.gif") as im:
original = im.copy()
im.palette.dirty = 1
assert_image_equal(im.convert("RGB"), original.convert("RGB"))
def test_getcolor():
palette = ImagePalette.ImagePalette()
assert len(palette.palette) == 0
assert len(palette.colors) == 0
test_map = {}
for i in range(256):
test_map[palette.getcolor((i, i, i))] = i
assert len(test_map) == 256
# Colors can be converted between RGB and RGBA
rgba_palette = ImagePalette.ImagePalette("RGBA")
assert rgba_palette.getcolor((0, 0, 0)) == rgba_palette.getcolor((0, 0, 0, 255))
assert palette.getcolor((0, 0, 0)) == palette.getcolor((0, 0, 0, 255))
# An error is raised when the palette is full
with pytest.raises(ValueError):
palette.getcolor((1, 2, 3))
# But not if the image is not using one of the palette entries
palette.getcolor((1, 2, 3), image=Image.new("P", (1, 1)))
# Test unknown color specifier
with pytest.raises(ValueError):
palette.getcolor("unknown")
def test_getcolor_rgba_color_rgb_palette():
palette = ImagePalette.ImagePalette("RGB")
# Opaque RGBA colors are converted
assert palette.getcolor((0, 0, 0, 255)) == palette.getcolor((0, 0, 0))
with pytest.raises(ValueError):
palette.getcolor((0, 0, 0, 128))
@pytest.mark.parametrize(
"index, palette",
[
# Test when the palette is not full
(0, ImagePalette.ImagePalette()),
# Test when the palette is full
(255, ImagePalette.ImagePalette("RGB", list(range(256)) * 3)),
],
)
def test_getcolor_not_special(index, palette):
im = Image.new("P", (1, 1))
# Do not use transparency index as a new color
im.info["transparency"] = index
index1 = palette.getcolor((0, 0, 0), im)
assert index1 != index
# Do not use background index as a new color
im.info["background"] = index1
index2 = palette.getcolor((0, 0, 1), im)
assert index2 not in (index, index1)
def test_file(tmp_path):
palette = ImagePalette.ImagePalette("RGB", list(range(256)) * 3)
f = str(tmp_path / "temp.lut")
palette.save(f)
p = ImagePalette.load(f)
# load returns raw palette information
assert len(p[0]) == 768
assert p[1] == "RGB"
p = ImagePalette.raw(p[1], p[0])
assert isinstance(p, ImagePalette.ImagePalette)
assert p.palette == palette.tobytes()
def test_make_linear_lut():
# Arrange
black = 0
white = 255
# Act
lut = ImagePalette.make_linear_lut(black, white)
# Assert
assert isinstance(lut, list)
assert len(lut) == 256
# Check values
for i in range(0, len(lut)):
assert lut[i] == i
def test_make_linear_lut_not_yet_implemented():
# Update after FIXME
# Arrange
black = 1
white = 255
# Act
with pytest.raises(NotImplementedError):
ImagePalette.make_linear_lut(black, white)
def test_make_gamma_lut():
# Arrange
exp = 5
# Act
lut = ImagePalette.make_gamma_lut(exp)
# Assert
assert isinstance(lut, list)
assert len(lut) == 256
# Check a few values
assert lut[0] == 0
assert lut[63] == 0
assert lut[127] == 8
assert lut[191] == 60
assert lut[255] == 255
def test_rawmode_valueerrors(tmp_path):
# Arrange
palette = ImagePalette.raw("RGB", list(range(256)) * 3)
# Act / Assert
with pytest.raises(ValueError):
palette.tobytes()
with pytest.raises(ValueError):
palette.getcolor((1, 2, 3))
f = str(tmp_path / "temp.lut")
with pytest.raises(ValueError):
palette.save(f)
def test_getdata():
# Arrange
data_in = list(range(256)) * 3
palette = ImagePalette.ImagePalette("RGB", data_in)
# Act
mode, data_out = palette.getdata()
# Assert
assert mode == "RGB"
def test_rawmode_getdata():
# Arrange
data_in = list(range(256)) * 3
palette = ImagePalette.raw("RGB", data_in)
# Act
rawmode, data_out = palette.getdata()
# Assert
assert rawmode == "RGB"
assert data_in == data_out
def test_2bit_palette(tmp_path):
# issue #2258, 2 bit palettes are corrupted.
outfile = str(tmp_path / "temp.png")
rgb = b"\x00" * 2 + b"\x01" * 2 + b"\x02" * 2
img = Image.frombytes("P", (6, 1), rgb)
img.putpalette(b"\xFF\x00\x00\x00\xFF\x00\x00\x00\xFF") # RGB
img.save(outfile, format="PNG")
assert_image_equal_tofile(img, outfile)
def test_invalid_palette():
with pytest.raises(OSError):
ImagePalette.load("Tests/images/hopper.jpg")