Pillow/Tests/test_box_blur.py

from PIL import Image, ImageFilter

from .helper import PillowTestCase

sample = Image.new("L", (7, 5))
# fmt: off
sample.putdata(sum([
    [210, 50,  20,  10,  220, 230, 80],
    [190, 210, 20,  180, 170, 40,  110],
    [120, 210, 250, 60,  220, 0,   220],
    [220, 40,  230, 80,  130, 250, 40],
    [250, 0,   80,  30,  60,  20,  110],
], []))
# fmt: on


class TestBoxBlurApi(PillowTestCase):
    def test_imageops_box_blur(self):
        i = sample.filter(ImageFilter.BoxBlur(1))
        self.assertEqual(i.mode, sample.mode)
        self.assertEqual(i.size, sample.size)
        self.assertIsInstance(i, Image.Image)


class TestBoxBlur(PillowTestCase):
    def box_blur(self, image, radius=1, n=1):
        return image._new(image.im.box_blur(radius, n))

    def assertImage(self, im, data, delta=0):
        it = iter(im.getdata())
        for data_row in data:
            im_row = [next(it) for _ in range(im.size[0])]
            if any(
                abs(data_v - im_v) > delta for data_v, im_v in zip(data_row, im_row)
            ):
                self.assertEqual(im_row, data_row)
        self.assertRaises(StopIteration, next, it)

    def assertBlur(self, im, radius, data, passes=1, delta=0):
        # check grayscale image
        self.assertImage(self.box_blur(im, radius, passes), data, delta)
        rgba = Image.merge("RGBA", (im, im, im, im))
        for band in self.box_blur(rgba, radius, passes).split():
            self.assertImage(band, data, delta)

    def test_color_modes(self):
        self.assertRaises(ValueError, self.box_blur, sample.convert("1"))
        self.assertRaises(ValueError, self.box_blur, sample.convert("P"))
        self.box_blur(sample.convert("L"))
        self.box_blur(sample.convert("LA"))
        self.box_blur(sample.convert("LA").convert("La"))
        self.assertRaises(ValueError, self.box_blur, sample.convert("I"))
        self.assertRaises(ValueError, self.box_blur, sample.convert("F"))
        self.box_blur(sample.convert("RGB"))
        self.box_blur(sample.convert("RGBA"))
        self.box_blur(sample.convert("RGBA").convert("RGBa"))
        self.box_blur(sample.convert("CMYK"))
        self.assertRaises(ValueError, self.box_blur, sample.convert("YCbCr"))

    def test_radius_0(self):
        self.assertBlur(
            sample,
            0,
            [
                # fmt: off
                [210, 50,  20,  10,  220, 230, 80],
                [190, 210, 20,  180, 170, 40,  110],
                [120, 210, 250, 60,  220, 0,   220],
                [220, 40,  230, 80,  130, 250, 40],
                [250, 0,   80,  30,  60,  20,  110],
                # fmt: on
            ],
        )

    def test_radius_0_02(self):
        self.assertBlur(
            sample,
            0.02,
            [
                # fmt: off
                [206, 55,  20,  17,  215, 223, 83],
                [189, 203, 31,  171, 169, 46,  110],
                [125, 206, 241, 69,  210, 13,  210],
                [215, 49,  221, 82,  131, 235, 48],
                [244, 7,   80,  32,  60,  27,  107],
                # fmt: on
            ],
            delta=2,
        )

    def test_radius_0_05(self):
        self.assertBlur(
            sample,
            0.05,
            [
                # fmt: off
                [202, 62,  22,  27,  209, 215, 88],
                [188, 194, 44,  161, 168, 56,  111],
                [131, 201, 229, 81,  198, 31,  198],
                [209, 62,  209, 86,  133, 216, 59],
                [237, 17,  80,  36,  60,  35,  103],
                # fmt: on
            ],
            delta=2,
        )

    def test_radius_0_1(self):
        self.assertBlur(
            sample,
            0.1,
            [
                # fmt: off
                [196, 72,  24,  40,  200, 203, 93],
                [187, 183, 62,  148, 166, 68,  111],
                [139, 193, 213, 96,  182, 54,  182],
                [201, 78,  193, 91,  133, 191, 73],
                [227, 31,  80,  42,  61,  47,  99],
                # fmt: on
            ],
            delta=1,
        )

    def test_radius_0_5(self):
        self.assertBlur(
            sample,
            0.5,
            [
                # fmt: off
                [176, 101, 46,  83,  163, 165, 111],
                [176, 149, 108, 122, 144, 120, 117],
                [164, 171, 159, 141, 134, 119, 129],
                [170, 136, 133, 114, 116, 124, 109],
                [184, 95,  72,  70,  69,  81,  89],
                # fmt: on
            ],
            delta=1,
        )

    def test_radius_1(self):
        self.assertBlur(
            sample,
            1,
            [
                # fmt: off
                [170, 109, 63,  97,  146, 153, 116],
                [168, 142, 112, 128, 126, 143, 121],
                [169, 166, 142, 149, 126, 131, 114],
                [159, 156, 109, 127, 94,  117, 112],
                [164, 128, 63,  87,  76,  89,  90],
                # fmt: on
            ],
            delta=1,
        )

    def test_radius_1_5(self):
        self.assertBlur(
            sample,
            1.5,
            [
                # fmt: off
                [155, 120, 105, 112, 124, 137, 130],
                [160, 136, 124, 125, 127, 134, 130],
                [166, 147, 130, 125, 120, 121, 119],
                [168, 145, 119, 109, 103, 105, 110],
                [168, 134, 96,  85,  85,  89,  97],
                # fmt: on
            ],
            delta=1,
        )

    def test_radius_bigger_then_half(self):
        self.assertBlur(
            sample,
            3,
            [
                # fmt: off
                [144, 145, 142, 128, 114, 115, 117],
                [148, 145, 137, 122, 109, 111, 112],
                [152, 145, 131, 117, 103, 107, 108],
                [156, 144, 126, 111, 97,  102, 103],
                [160, 144, 121, 106, 92,  98,  99],
                # fmt: on
            ],
            delta=1,
        )

    def test_radius_bigger_then_width(self):
        self.assertBlur(
            sample,
            10,
            [
                [158, 153, 147, 141, 135, 129, 123],
                [159, 153, 147, 141, 136, 130, 124],
                [159, 154, 148, 142, 136, 130, 124],
                [160, 154, 148, 142, 137, 131, 125],
                [160, 155, 149, 143, 137, 131, 125],
            ],
            delta=0,
        )

    def test_extreme_large_radius(self):
        self.assertBlur(
            sample,
            600,
            [
                [162, 162, 162, 162, 162, 162, 162],
                [162, 162, 162, 162, 162, 162, 162],
                [162, 162, 162, 162, 162, 162, 162],
                [162, 162, 162, 162, 162, 162, 162],
                [162, 162, 162, 162, 162, 162, 162],
            ],
            delta=1,
        )

    def test_two_passes(self):
        self.assertBlur(
            sample,
            1,
            [
                # fmt: off
                [153, 123, 102, 109, 132, 135, 129],
                [159, 138, 123, 121, 133, 131, 126],
                [162, 147, 136, 124, 127, 121, 121],
                [159, 140, 125, 108, 111, 106, 108],
                [154, 126, 105, 87,  94,  93,  97],
                # fmt: on
            ],
            passes=2,
            delta=1,
        )

    def test_three_passes(self):
        self.assertBlur(
            sample,
            1,
            [
                # fmt: off
                [146, 131, 116, 118, 126, 131, 130],
                [151, 138, 125, 123, 126, 128, 127],
                [154, 143, 129, 123, 120, 120, 119],
                [152, 139, 122, 113, 108, 108, 108],
                [148, 132, 112, 102, 97,  99,  100],
                # fmt: on
            ],
            passes=3,
            delta=1,
        )