Pillow/Tests/test_image_rotate.py

128 lines
4.8 KiB
Python

from PIL import Image
from .helper import PillowTestCase, assert_image_equal, assert_image_similar, hopper
class TestImageRotate(PillowTestCase):
def rotate(self, im, mode, angle, center=None, translate=None):
out = im.rotate(angle, center=center, translate=translate)
self.assertEqual(out.mode, mode)
self.assertEqual(out.size, im.size) # default rotate clips output
out = im.rotate(angle, center=center, translate=translate, expand=1)
self.assertEqual(out.mode, mode)
if angle % 180 == 0:
self.assertEqual(out.size, im.size)
elif im.size == (0, 0):
self.assertEqual(out.size, im.size)
else:
self.assertNotEqual(out.size, im.size)
def test_mode(self):
for mode in ("1", "P", "L", "RGB", "I", "F"):
im = hopper(mode)
self.rotate(im, mode, 45)
def test_angle(self):
for angle in (0, 90, 180, 270):
with Image.open("Tests/images/test-card.png") as im:
self.rotate(im, im.mode, angle)
def test_zero(self):
for angle in (0, 45, 90, 180, 270):
im = Image.new("RGB", (0, 0))
self.rotate(im, im.mode, angle)
def test_resample(self):
# 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(self):
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(self):
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(self):
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(self):
# 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(self):
# 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(self):
im = hopper()
self.rotate(im, im.mode, 45, center=(0, 0))
self.rotate(im, im.mode, 45, translate=(im.size[0] / 2, 0))
self.rotate(im, im.mode, 45, center=(0, 0), translate=(im.size[0] / 2, 0))
def test_rotate_no_fill(self):
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(self):
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(self):
# Alpha images are handled differently internally
im = Image.new("RGBA", (10, 10), "green")
im = im.rotate(45, expand=1)
corner = im.getpixel((0, 0))
self.assertEqual(corner, (0, 0, 0, 0))
def test_alpha_rotate_with_fill(self):
# 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))
self.assertEqual(corner, (255, 0, 0, 255))