Pillow/Tests/test_image_rotate.py
2020-02-13 12:15:05 +02:00

141 lines
4.2 KiB
Python

from PIL import Image
from .helper import assert_image_equal, assert_image_similar, hopper
def rotate(im, mode, angle, center=None, translate=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
def test_mode():
for mode in ("1", "P", "L", "RGB", "I", "F"):
im = hopper(mode)
rotate(im, mode, 45)
def test_angle():
for angle in (0, 90, 180, 270):
with Image.open("Tests/images/test-card.png") as im:
rotate(im, im.mode, angle)
def test_zero():
for angle in (0, 45, 90, 180, 270):
im = Image.new("RGB", (0, 0))
rotate(im, im.mode, angle)
def test_resample():
# Target image creation, inspected by eye.
# >>> im = Image.open('Tests/images/hopper.ppm')
# >>> im = im.rotate(45, resample=Image.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.NEAREST, 10),
(Image.BILINEAR, 5),
(Image.BICUBIC, 0),
):
im = hopper()
im = im.rotate(45, resample=resample, expand=True)
assert_image_similar(im, target, epsilon)
def test_center_0():
im = hopper()
im = im.rotate(45, center=(0, 0), resample=Image.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():
im = hopper()
im = im.rotate(45, center=(14, 14), resample=Image.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():
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.BICUBIC)
assert_image_similar(im, target, 1)
def test_fastpath_center():
# 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():
# 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():
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():
im = Image.new("RGB", (100, 100), "green")
im = im.rotate(45)
with Image.open("Tests/images/rotate_45_no_fill.png") as target:
assert_image_equal(im, target)
def test_rotate_with_fill():
im = Image.new("RGB", (100, 100), "green")
im = im.rotate(45, fillcolor="white")
with Image.open("Tests/images/rotate_45_with_fill.png") as target:
assert_image_equal(im, target)
def test_alpha_rotate_no_fill():
# 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():
# 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)