Pillow/Tests/test_image_rotate.py
2024-06-05 22:27:23 +10:00

157 lines
4.7 KiB
Python

from __future__ import annotations
import pytest
from PIL import Image
from .helper import (
assert_image_equal,
assert_image_equal_tofile,
assert_image_similar,
hopper,
)
def rotate(
im: Image.Image,
mode: str,
angle: int,
center: tuple[int, int] | None = None,
translate: tuple[int, int] | None = None,
) -> None:
out = im.rotate(angle, center=center, translate=translate)
assert out.mode == mode
assert out.size == im.size # default rotate clips output
out = im.rotate(angle, center=center, translate=translate, expand=1)
assert out.mode == mode
if angle % 180 == 0:
assert out.size == im.size
elif im.size == (0, 0):
assert out.size == im.size
else:
assert out.size != im.size
@pytest.mark.parametrize("mode", ("1", "P", "L", "RGB", "I", "F"))
def test_mode(mode: str) -> None:
im = hopper(mode)
rotate(im, mode, 45)
@pytest.mark.parametrize("angle", (0, 90, 180, 270))
def test_angle(angle: int) -> None:
with Image.open("Tests/images/test-card.png") as im:
rotate(im, im.mode, angle)
im = hopper()
assert_image_equal(im.rotate(angle), im.rotate(angle, expand=1))
@pytest.mark.parametrize("angle", (0, 45, 90, 180, 270))
def test_zero(angle: int) -> None:
im = Image.new("RGB", (0, 0))
rotate(im, im.mode, angle)
def test_resample() -> None:
# Target image creation, inspected by eye.
# >>> im = Image.open('Tests/images/hopper.ppm')
# >>> im = im.rotate(45, resample=Image.Resampling.BICUBIC, expand=True)
# >>> im.save('Tests/images/hopper_45.png')
with Image.open("Tests/images/hopper_45.png") as target:
for resample, epsilon in (
(Image.Resampling.NEAREST, 10),
(Image.Resampling.BILINEAR, 5),
(Image.Resampling.BICUBIC, 0),
):
im = hopper()
im = im.rotate(45, resample=resample, expand=True)
assert_image_similar(im, target, epsilon)
def test_center_0() -> None:
im = hopper()
im = im.rotate(45, center=(0, 0), resample=Image.Resampling.BICUBIC)
with Image.open("Tests/images/hopper_45.png") as target:
target_origin = target.size[1] / 2
target = target.crop((0, target_origin, 128, target_origin + 128))
assert_image_similar(im, target, 15)
def test_center_14() -> None:
im = hopper()
im = im.rotate(45, center=(14, 14), resample=Image.Resampling.BICUBIC)
with Image.open("Tests/images/hopper_45.png") as target:
target_origin = target.size[1] / 2 - 14
target = target.crop((6, target_origin, 128 + 6, target_origin + 128))
assert_image_similar(im, target, 10)
def test_translate() -> None:
im = hopper()
with Image.open("Tests/images/hopper_45.png") as target:
target_origin = (target.size[1] / 2 - 64) - 5
target = target.crop(
(target_origin, target_origin, target_origin + 128, target_origin + 128)
)
im = im.rotate(45, translate=(5, 5), resample=Image.Resampling.BICUBIC)
assert_image_similar(im, target, 1)
def test_fastpath_center() -> None:
# if the center is -1,-1 and we rotate by 90<=x<=270 the
# resulting image should be black
for angle in (90, 180, 270):
im = hopper().rotate(angle, center=(-1, -1))
assert_image_equal(im, Image.new("RGB", im.size, "black"))
def test_fastpath_translate() -> None:
# if we post-translate by -128
# resulting image should be black
for angle in (0, 90, 180, 270):
im = hopper().rotate(angle, translate=(-128, -128))
assert_image_equal(im, Image.new("RGB", im.size, "black"))
def test_center() -> None:
im = hopper()
rotate(im, im.mode, 45, center=(0, 0))
rotate(im, im.mode, 45, translate=(im.size[0] // 2, 0))
rotate(im, im.mode, 45, center=(0, 0), translate=(im.size[0] // 2, 0))
def test_rotate_no_fill() -> None:
im = Image.new("RGB", (100, 100), "green")
im = im.rotate(45)
assert_image_equal_tofile(im, "Tests/images/rotate_45_no_fill.png")
def test_rotate_with_fill() -> None:
im = Image.new("RGB", (100, 100), "green")
im = im.rotate(45, fillcolor="white")
assert_image_equal_tofile(im, "Tests/images/rotate_45_with_fill.png")
def test_alpha_rotate_no_fill() -> None:
# Alpha images are handled differently internally
im = Image.new("RGBA", (10, 10), "green")
im = im.rotate(45, expand=1)
corner = im.getpixel((0, 0))
assert corner == (0, 0, 0, 0)
def test_alpha_rotate_with_fill() -> None:
# Alpha images are handled differently internally
im = Image.new("RGBA", (10, 10), "green")
im = im.rotate(45, expand=1, fillcolor=(255, 0, 0, 255))
corner = im.getpixel((0, 0))
assert corner == (255, 0, 0, 255)