Pillow/Tests/test_imageops.py

from .helper import PillowTestCase, hopper

from PIL import Image
from PIL import ImageOps

try:
    from PIL import _webp
    HAVE_WEBP = True
except ImportError:
    HAVE_WEBP = False


class TestImageOps(PillowTestCase):

    class Deformer(object):
        def getmesh(self, im):
            x, y = im.size
            return [((0, 0, x, y), (0, 0, x, 0, x, y, y, 0))]

    deformer = Deformer()

    def test_sanity(self):

        ImageOps.autocontrast(hopper("L"))
        ImageOps.autocontrast(hopper("RGB"))

        ImageOps.autocontrast(hopper("L"), cutoff=10)
        ImageOps.autocontrast(hopper("L"), ignore=[0, 255])

        ImageOps.colorize(hopper("L"), (0, 0, 0), (255, 255, 255))
        ImageOps.colorize(hopper("L"), "black", "white")

        ImageOps.pad(hopper("L"), (128, 128))
        ImageOps.pad(hopper("RGB"), (128, 128))

        ImageOps.crop(hopper("L"), 1)
        ImageOps.crop(hopper("RGB"), 1)

        ImageOps.deform(hopper("L"), self.deformer)
        ImageOps.deform(hopper("RGB"), self.deformer)

        ImageOps.equalize(hopper("L"))
        ImageOps.equalize(hopper("RGB"))

        ImageOps.expand(hopper("L"), 1)
        ImageOps.expand(hopper("RGB"), 1)
        ImageOps.expand(hopper("L"), 2, "blue")
        ImageOps.expand(hopper("RGB"), 2, "blue")

        ImageOps.fit(hopper("L"), (128, 128))
        ImageOps.fit(hopper("RGB"), (128, 128))

        ImageOps.flip(hopper("L"))
        ImageOps.flip(hopper("RGB"))

        ImageOps.grayscale(hopper("L"))
        ImageOps.grayscale(hopper("RGB"))

        ImageOps.invert(hopper("L"))
        ImageOps.invert(hopper("RGB"))

        ImageOps.mirror(hopper("L"))
        ImageOps.mirror(hopper("RGB"))

        ImageOps.posterize(hopper("L"), 4)
        ImageOps.posterize(hopper("RGB"), 4)

        ImageOps.solarize(hopper("L"))
        ImageOps.solarize(hopper("RGB"))

        ImageOps.exif_transpose(hopper("L"))
        ImageOps.exif_transpose(hopper("RGB"))

    def test_1pxfit(self):
        # Division by zero in equalize if image is 1 pixel high
        newimg = ImageOps.fit(hopper("RGB").resize((1, 1)), (35, 35))
        self.assertEqual(newimg.size, (35, 35))

        newimg = ImageOps.fit(hopper("RGB").resize((1, 100)), (35, 35))
        self.assertEqual(newimg.size, (35, 35))

        newimg = ImageOps.fit(hopper("RGB").resize((100, 1)), (35, 35))
        self.assertEqual(newimg.size, (35, 35))

    def test_pad(self):
        # Same ratio
        im = hopper()
        new_size = (im.width * 2, im.height * 2)
        new_im = ImageOps.pad(im, new_size)
        self.assertEqual(new_im.size, new_size)

        for label, color, new_size in [
            ("h", None, (im.width * 4, im.height * 2)),
            ("v", "#f00", (im.width * 2, im.height * 4))
        ]:
            for i, centering in enumerate([(0, 0), (0.5, 0.5), (1, 1)]):
                new_im = ImageOps.pad(im, new_size,
                                      color=color, centering=centering)
                self.assertEqual(new_im.size, new_size)

                target = Image.open(
                    "Tests/images/imageops_pad_"+label+"_"+str(i)+".jpg")
                self.assert_image_similar(new_im, target, 6)

    def test_pil163(self):
        # Division by zero in equalize if < 255 pixels in image (@PIL163)

        i = hopper("RGB").resize((15, 16))

        ImageOps.equalize(i.convert("L"))
        ImageOps.equalize(i.convert("P"))
        ImageOps.equalize(i.convert("RGB"))

    def test_scale(self):
        # Test the scaling function
        i = hopper("L").resize((50, 50))

        with self.assertRaises(ValueError):
            ImageOps.scale(i, -1)

        newimg = ImageOps.scale(i, 1)
        self.assertEqual(newimg.size, (50, 50))

        newimg = ImageOps.scale(i, 2)
        self.assertEqual(newimg.size, (100, 100))

        newimg = ImageOps.scale(i, 0.5)
        self.assertEqual(newimg.size, (25, 25))

    def test_colorize_2color(self):
        # Test the colorizing function with 2-color functionality

        # Open test image (256px by 10px, black to white)
        im = Image.open("Tests/images/bw_gradient.png")
        im = im.convert("L")

        # Create image with original 2-color functionality
        im_test = ImageOps.colorize(im, 'red', 'green')

        # Test output image (2-color)
        left = (0, 1)
        middle = (127, 1)
        right = (255, 1)
        self.assert_tuple_approx_equal(im_test.getpixel(left),
                                       (255, 0, 0),
                                       threshold=1,
                                       msg='black test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(middle),
                                       (127, 63, 0),
                                       threshold=1,
                                       msg='mid test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(right),
                                       (0, 127, 0),
                                       threshold=1,
                                       msg='white test pixel incorrect')

    def test_colorize_2color_offset(self):
        # Test the colorizing function with 2-color functionality and offset

        # Open test image (256px by 10px, black to white)
        im = Image.open("Tests/images/bw_gradient.png")
        im = im.convert("L")

        # Create image with original 2-color functionality with offsets
        im_test = ImageOps.colorize(im,
                                    black='red',
                                    white='green',
                                    blackpoint=50,
                                    whitepoint=100)

        # Test output image (2-color) with offsets
        left = (25, 1)
        middle = (75, 1)
        right = (125, 1)
        self.assert_tuple_approx_equal(im_test.getpixel(left),
                                       (255, 0, 0),
                                       threshold=1,
                                       msg='black test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(middle),
                                       (127, 63, 0),
                                       threshold=1,
                                       msg='mid test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(right),
                                       (0, 127, 0),
                                       threshold=1,
                                       msg='white test pixel incorrect')

    def test_colorize_3color_offset(self):
        # Test the colorizing function with 3-color functionality and offset

        # Open test image (256px by 10px, black to white)
        im = Image.open("Tests/images/bw_gradient.png")
        im = im.convert("L")

        # Create image with new three color functionality with offsets
        im_test = ImageOps.colorize(im,
                                    black='red',
                                    white='green',
                                    mid='blue',
                                    blackpoint=50,
                                    whitepoint=200,
                                    midpoint=100)

        # Test output image (3-color) with offsets
        left = (25, 1)
        left_middle = (75, 1)
        middle = (100, 1)
        right_middle = (150, 1)
        right = (225, 1)
        self.assert_tuple_approx_equal(im_test.getpixel(left),
                                       (255, 0, 0),
                                       threshold=1,
                                       msg='black test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(left_middle),
                                       (127, 0, 127),
                                       threshold=1,
                                       msg='low-mid test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(middle),
                                       (0, 0, 255),
                                       threshold=1,
                                       msg='mid incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(right_middle),
                                       (0, 63, 127),
                                       threshold=1,
                                       msg='high-mid test pixel incorrect')
        self.assert_tuple_approx_equal(im_test.getpixel(right),
                                       (0, 127, 0),
                                       threshold=1,
                                       msg='white test pixel incorrect')

    def test_exif_transpose(self):
        exts = [".jpg"]
        if HAVE_WEBP and _webp.HAVE_WEBPANIM:
            exts.append(".webp")
        for ext in exts:
            base_im = Image.open("Tests/images/hopper"+ext)

            orientations = [base_im]
            for i in range(2, 9):
                im = Image.open("Tests/images/hopper_orientation_"+str(i)+ext)
                orientations.append(im)
            for i, orientation_im in enumerate(orientations):
                for im in [
                    orientation_im,        # ImageFile
                    orientation_im.copy()  # Image
                ]:
                    if i == 0:
                        self.assertNotIn("exif", im.info)
                    else:
                        original_exif = im.info["exif"]
                    transposed_im = ImageOps.exif_transpose(im)
                    self.assert_image_similar(base_im, transposed_im, 17)
                    if i == 0:
                        self.assertNotIn("exif", im.info)
                    else:
                        self.assertNotEqual(transposed_im.info["exif"], original_exif)

                        self.assertNotIn(0x0112, transposed_im.getexif())

                    # Repeat the operation, to test that it does not keep transposing
                    transposed_im2 = ImageOps.exif_transpose(transposed_im)
                    self.assert_image_equal(transposed_im2, transposed_im)