test_transforms.py

import math
import os
import random
import re
import sys
import textwrap
import warnings
from functools import partial

import numpy as np
import pytest
import torch
import torchvision.transforms as transforms
import torchvision.transforms._functional_tensor as F_t
import torchvision.transforms.functional as F
from PIL import Image
from torch._utils_internal import get_file_path_2

try:
    import accimage
except ImportError:
    accimage = None

try:
    from scipy import stats
except ImportError:
    stats = None

from common_utils import assert_equal, assert_run_python_script, cycle_over, float_dtypes, int_dtypes


GRACE_HOPPER = get_file_path_2(
    os.path.dirname(os.path.abspath(__file__)), "assets", "encode_jpeg", "grace_hopper_517x606.jpg"
)


def _get_grayscale_test_image(img, fill=None):
    img = img.convert("L")
    fill = (fill[0],) if isinstance(fill, tuple) else fill
    return img, fill


class TestConvertImageDtype:
    @pytest.mark.parametrize("input_dtype, output_dtype", cycle_over(float_dtypes()))
    def test_float_to_float(self, input_dtype, output_dtype):
        input_image = torch.tensor((0.0, 1.0), dtype=input_dtype)
        transform = transforms.ConvertImageDtype(output_dtype)
        transform_script = torch.jit.script(F.convert_image_dtype)

        output_image = transform(input_image)
        output_image_script = transform_script(input_image, output_dtype)

        torch.testing.assert_close(output_image_script, output_image, rtol=0.0, atol=1e-6)

        actual_min, actual_max = output_image.tolist()
        desired_min, desired_max = 0.0, 1.0

        assert abs(actual_min - desired_min) < 1e-7
        assert abs(actual_max - desired_max) < 1e-7

    @pytest.mark.parametrize("input_dtype", float_dtypes())
    @pytest.mark.parametrize("output_dtype", int_dtypes())
    def test_float_to_int(self, input_dtype, output_dtype):
        input_image = torch.tensor((0.0, 1.0), dtype=input_dtype)
        transform = transforms.ConvertImageDtype(output_dtype)
        transform_script = torch.jit.script(F.convert_image_dtype)

        if (input_dtype == torch.float32 and output_dtype in (torch.int32, torch.int64)) or (
            input_dtype == torch.float64 and output_dtype == torch.int64
        ):
            with pytest.raises(RuntimeError):
                transform(input_image)
        else:
            output_image = transform(input_image)
            output_image_script = transform_script(input_image, output_dtype)

            torch.testing.assert_close(output_image_script, output_image, rtol=0.0, atol=1e-6)

            actual_min, actual_max = output_image.tolist()
            desired_min, desired_max = 0, torch.iinfo(output_dtype).max

            assert actual_min == desired_min
            assert actual_max == desired_max

    @pytest.mark.parametrize("input_dtype", int_dtypes())
    @pytest.mark.parametrize("output_dtype", float_dtypes())
    def test_int_to_float(self, input_dtype, output_dtype):
        input_image = torch.tensor((0, torch.iinfo(input_dtype).max), dtype=input_dtype)
        transform = transforms.ConvertImageDtype(output_dtype)
        transform_script = torch.jit.script(F.convert_image_dtype)

        output_image = transform(input_image)
        output_image_script = transform_script(input_image, output_dtype)

        torch.testing.assert_close(output_image_script, output_image, rtol=0.0, atol=1e-6)

        actual_min, actual_max = output_image.tolist()
        desired_min, desired_max = 0.0, 1.0

        assert abs(actual_min - desired_min) < 1e-7
        assert actual_min >= desired_min
        assert abs(actual_max - desired_max) < 1e-7
        assert actual_max <= desired_max

    @pytest.mark.parametrize("input_dtype, output_dtype", cycle_over(int_dtypes()))
    def test_dtype_int_to_int(self, input_dtype, output_dtype):
        input_max = torch.iinfo(input_dtype).max
        input_image = torch.tensor((0, input_max), dtype=input_dtype)
        output_max = torch.iinfo(output_dtype).max

        transform = transforms.ConvertImageDtype(output_dtype)
        transform_script = torch.jit.script(F.convert_image_dtype)

        output_image = transform(input_image)
        output_image_script = transform_script(input_image, output_dtype)

        torch.testing.assert_close(
            output_image_script,
            output_image,
            rtol=0.0,
            atol=1e-6,
            msg=f"{output_image_script} vs {output_image}",
        )

        actual_min, actual_max = output_image.tolist()
        desired_min, desired_max = 0, output_max

        # see https://github.com/pytorch/vision/pull/2078#issuecomment-641036236 for details
        if input_max >= output_max:
            error_term = 0
        else:
            error_term = 1 - (torch.iinfo(output_dtype).max + 1) // (torch.iinfo(input_dtype).max + 1)

        assert actual_min == desired_min
        assert actual_max == (desired_max + error_term)

    @pytest.mark.parametrize("input_dtype, output_dtype", cycle_over(int_dtypes()))
    def test_int_to_int_consistency(self, input_dtype, output_dtype):
        input_max = torch.iinfo(input_dtype).max
        input_image = torch.tensor((0, input_max), dtype=input_dtype)

        output_max = torch.iinfo(output_dtype).max
        if output_max <= input_max:
            return

        transform = transforms.ConvertImageDtype(output_dtype)
        inverse_transfrom = transforms.ConvertImageDtype(input_dtype)
        output_image = inverse_transfrom(transform(input_image))

        actual_min, actual_max = output_image.tolist()
        desired_min, desired_max = 0, input_max

        assert actual_min == desired_min
        assert actual_max == desired_max


@pytest.mark.skipif(accimage is None, reason="accimage not available")
class TestAccImage:
    def test_accimage_to_tensor(self):
        trans = transforms.PILToTensor()

        expected_output = trans(Image.open(GRACE_HOPPER).convert("RGB"))
        output = trans(accimage.Image(GRACE_HOPPER))

        torch.testing.assert_close(output, expected_output)

    def test_accimage_pil_to_tensor(self):
        trans = transforms.PILToTensor()

        expected_output = trans(Image.open(GRACE_HOPPER).convert("RGB"))
        output = trans(accimage.Image(GRACE_HOPPER))

        assert expected_output.size() == output.size()
        torch.testing.assert_close(output, expected_output)

    def test_accimage_resize(self):
        trans = transforms.Compose(
            [
                transforms.Resize(256, interpolation=Image.LINEAR),
                transforms.PILToTensor(),
                transforms.ConvertImageDtype(dtype=torch.float),
            ]
        )

        # Checking if Compose, Resize and ToTensor can be printed as string
        trans.__repr__()

        expected_output = trans(Image.open(GRACE_HOPPER).convert("RGB"))
        output = trans(accimage.Image(GRACE_HOPPER))

        assert expected_output.size() == output.size()
        assert np.abs((expected_output - output).mean()) < 1e-3
        assert (expected_output - output).var() < 1e-5
        # note the high absolute tolerance
        torch.testing.assert_close(output.numpy(), expected_output.numpy(), rtol=1e-5, atol=5e-2)

    def test_accimage_crop(self):
        trans = transforms.Compose(
            [transforms.CenterCrop(256), transforms.PILToTensor(), transforms.ConvertImageDtype(dtype=torch.float)]
        )

        # Checking if Compose, CenterCrop and ToTensor can be printed as string
        trans.__repr__()

        expected_output = trans(Image.open(GRACE_HOPPER).convert("RGB"))
        output = trans(accimage.Image(GRACE_HOPPER))

        assert expected_output.size() == output.size()
        torch.testing.assert_close(output, expected_output)


class TestToTensor:
    @pytest.mark.parametrize("channels", [1, 3, 4])
    def test_to_tensor(self, channels):
        height, width = 4, 4
        trans = transforms.ToTensor()
        np_rng = np.random.RandomState(0)

        input_data = torch.ByteTensor(channels, height, width).random_(0, 255).float().div_(255)
        img = transforms.ToPILImage()(input_data)
        output = trans(img)
        torch.testing.assert_close(output, input_data)

        ndarray = np_rng.randint(low=0, high=255, size=(height, width, channels)).astype(np.uint8)
        output = trans(ndarray)
        expected_output = ndarray.transpose((2, 0, 1)) / 255.0
        torch.testing.assert_close(output.numpy(), expected_output, check_dtype=False)

        ndarray = np_rng.rand(height, width, channels).astype(np.float32)
        output = trans(ndarray)
        expected_output = ndarray.transpose((2, 0, 1))
        torch.testing.assert_close(output.numpy(), expected_output, check_dtype=False)

        # separate test for mode '1' PIL images
        input_data = torch.ByteTensor(1, height, width).bernoulli_()
        img = transforms.ToPILImage()(input_data.mul(255)).convert("1")
        output = trans(img)
        torch.testing.assert_close(input_data, output, check_dtype=False)

    def test_to_tensor_errors(self):
        height, width = 4, 4
        trans = transforms.ToTensor()
        np_rng = np.random.RandomState(0)

        with pytest.raises(TypeError):
            trans(np_rng.rand(1, height, width).tolist())

        with pytest.raises(ValueError):
            trans(np_rng.rand(height))

        with pytest.raises(ValueError):
            trans(np_rng.rand(1, 1, height, width))

    @pytest.mark.parametrize("dtype", [torch.float16, torch.float, torch.double])
    def test_to_tensor_with_other_default_dtypes(self, dtype):
        np_rng = np.random.RandomState(0)
        current_def_dtype = torch.get_default_dtype()

        t = transforms.ToTensor()
        np_arr = np_rng.randint(0, 255, (32, 32, 3), dtype=np.uint8)
        img = Image.fromarray(np_arr)

        torch.set_default_dtype(dtype)
        res = t(img)
        assert res.dtype == dtype, f"{res.dtype} vs {dtype}"

        torch.set_default_dtype(current_def_dtype)

    @pytest.mark.parametrize("channels", [1, 3, 4])
    def test_pil_to_tensor(self, channels):
        height, width = 4, 4
        trans = transforms.PILToTensor()
        np_rng = np.random.RandomState(0)

        input_data = torch.ByteTensor(channels, height, width).random_(0, 255)
        img = transforms.ToPILImage()(input_data)
        output = trans(img)
        torch.testing.assert_close(input_data, output)

        input_data = np_rng.randint(low=0, high=255, size=(height, width, channels)).astype(np.uint8)
        img = transforms.ToPILImage()(input_data)
        output = trans(img)
        expected_output = input_data.transpose((2, 0, 1))
        torch.testing.assert_close(output.numpy(), expected_output)

        input_data = torch.as_tensor(np_rng.rand(channels, height, width).astype(np.float32))
        img = transforms.ToPILImage()(input_data)  # CHW -> HWC and (* 255).byte()
        output = trans(img)  # HWC -> CHW
        expected_output = (input_data * 255).byte()
        torch.testing.assert_close(output, expected_output)

        # separate test for mode '1' PIL images
        input_data = torch.ByteTensor(1, height, width).bernoulli_()
        img = transforms.ToPILImage()(input_data.mul(255)).convert("1")
        output = trans(img).view(torch.uint8).bool().to(torch.uint8)
        torch.testing.assert_close(input_data, output)

    def test_pil_to_tensor_errors(self):
        height, width = 4, 4
        trans = transforms.PILToTensor()
        np_rng = np.random.RandomState(0)

        with pytest.raises(TypeError):
            trans(np_rng.rand(1, height, width).tolist())

        with pytest.raises(TypeError):
            trans(np_rng.rand(1, height, width))


def test_randomresized_params():
    height = random.randint(24, 32) * 2
    width = random.randint(24, 32) * 2
    img = torch.ones(3, height, width)
    to_pil_image = transforms.ToPILImage()
    img = to_pil_image(img)
    size = 100
    epsilon = 0.05
    min_scale = 0.25
    for _ in range(10):
        scale_min = max(round(random.random(), 2), min_scale)
        scale_range = (scale_min, scale_min + round(random.random(), 2))
        aspect_min = max(round(random.random(), 2), epsilon)
        aspect_ratio_range = (aspect_min, aspect_min + round(random.random(), 2))
        randresizecrop = transforms.RandomResizedCrop(size, scale_range, aspect_ratio_range, antialias=True)
        i, j, h, w = randresizecrop.get_params(img, scale_range, aspect_ratio_range)
        aspect_ratio_obtained = w / h
        assert (
            min(aspect_ratio_range) - epsilon <= aspect_ratio_obtained
            and aspect_ratio_obtained <= max(aspect_ratio_range) + epsilon
        ) or aspect_ratio_obtained == 1.0
        assert isinstance(i, int)
        assert isinstance(j, int)
        assert isinstance(h, int)
        assert isinstance(w, int)


@pytest.mark.parametrize(
    "height, width",
    [
        # height, width
        # square image
        (28, 28),
        (27, 27),
        # rectangular image: h < w
        (28, 34),
        (29, 35),
        # rectangular image: h > w
        (34, 28),
        (35, 29),
    ],
)
@pytest.mark.parametrize(
    "osize",
    [
        # single integer
        22,
        27,
        28,
        36,
        # single integer in tuple/list
        [
            22,
        ],
        (27,),
    ],
)
@pytest.mark.parametrize("max_size", (None, 37, 1000))
def test_resize(height, width, osize, max_size):
    img = Image.new("RGB", size=(width, height), color=127)

    t = transforms.Resize(osize, max_size=max_size, antialias=True)
    result = t(img)

    msg = f"{height}, {width} - {osize} - {max_size}"
    osize = osize[0] if isinstance(osize, (list, tuple)) else osize
    # If size is an int, smaller edge of the image will be matched to this number.
    # i.e, if height > width, then image will be rescaled to (size * height / width, size).
    if height < width:
        exp_w, exp_h = (int(osize * width / height), osize)  # (w, h)
        if max_size is not None and max_size < exp_w:
            exp_w, exp_h = max_size, int(max_size * exp_h / exp_w)
        assert result.size == (exp_w, exp_h), msg
    elif width < height:
        exp_w, exp_h = (osize, int(osize * height / width))  # (w, h)
        if max_size is not None and max_size < exp_h:
            exp_w, exp_h = int(max_size * exp_w / exp_h), max_size
        assert result.size == (exp_w, exp_h), msg
    else:
        exp_w, exp_h = (osize, osize)  # (w, h)
        if max_size is not None and max_size < osize:
            exp_w, exp_h = max_size, max_size
        assert result.size == (exp_w, exp_h), msg


@pytest.mark.parametrize(
    "height, width",
    [
        # height, width
        # square image
        (28, 28),
        (27, 27),
        # rectangular image: h < w
        (28, 34),
        (29, 35),
        # rectangular image: h > w
        (34, 28),
        (35, 29),
    ],
)
@pytest.mark.parametrize(
    "osize",
    [
        # two integers sequence output
        [22, 22],
        [22, 28],
        [22, 36],
        [27, 22],
        [36, 22],
        [28, 28],
        [28, 37],
        [37, 27],
        [37, 37],
    ],
)
def test_resize_sequence_output(height, width, osize):
    img = Image.new("RGB", size=(width, height), color=127)
    oheight, owidth = osize

    t = transforms.Resize(osize, antialias=True)
    result = t(img)

    assert (owidth, oheight) == result.size


def test_resize_antialias_error():
    osize = [37, 37]
    img = Image.new("RGB", size=(35, 29), color=127)

    with pytest.warns(UserWarning, match=r"Anti-alias option is always applied for PIL Image input"):
        t = transforms.Resize(osize, antialias=False)
        t(img)


def test_resize_antialias_default_warning():

    img = Image.new("RGB", size=(10, 10), color=127)
    # We make sure we don't warn for PIL images since the default behaviour doesn't change
    with warnings.catch_warnings():
        warnings.simplefilter("error")
        transforms.Resize((20, 20))(img)
        transforms.RandomResizedCrop((20, 20))(img)


@pytest.mark.parametrize("height, width", ((32, 64), (64, 32)))
def test_resize_size_equals_small_edge_size(height, width):
    # Non-regression test for https://github.com/pytorch/vision/issues/5405
    # max_size used to be ignored if size == small_edge_size
    max_size = 40
    img = Image.new("RGB", size=(width, height), color=127)

    small_edge = min(height, width)
    t = transforms.Resize(small_edge, max_size=max_size, antialias=True)
    result = t(img)
    assert max(result.size) == max_size


class TestPad:
    @pytest.mark.parametrize("fill", [85, 85.0])
    def test_pad(self, fill):
        height = random.randint(10, 32) * 2
        width = random.randint(10, 32) * 2
        img = torch.ones(3, height, width, dtype=torch.uint8)
        padding = random.randint(1, 20)
        result = transforms.Compose(
            [
                transforms.ToPILImage(),
                transforms.Pad(padding, fill=fill),
                transforms.PILToTensor(),
            ]
        )(img)
        assert result.size(1) == height + 2 * padding
        assert result.size(2) == width + 2 * padding
        # check that all elements in the padded region correspond
        # to the pad value
        h_padded = result[:, :padding, :]
        w_padded = result[:, :, :padding]
        torch.testing.assert_close(h_padded, torch.full_like(h_padded, fill_value=fill), rtol=0.0, atol=0.0)
        torch.testing.assert_close(w_padded, torch.full_like(w_padded, fill_value=fill), rtol=0.0, atol=0.0)
        pytest.raises(ValueError, transforms.Pad(padding, fill=(1, 2)), transforms.ToPILImage()(img))

    def test_pad_with_tuple_of_pad_values(self):
        height = random.randint(10, 32) * 2
        width = random.randint(10, 32) * 2
        img = transforms.ToPILImage()(torch.ones(3, height, width))

        padding = tuple(random.randint(1, 20) for _ in range(2))
        output = transforms.Pad(padding)(img)
        assert output.size == (width + padding[0] * 2, height + padding[1] * 2)

        padding = [random.randint(1, 20) for _ in range(4)]
        output = transforms.Pad(padding)(img)
        assert output.size[0] == width + padding[0] + padding[2]
        assert output.size[1] == height + padding[1] + padding[3]

        # Checking if Padding can be printed as string
        transforms.Pad(padding).__repr__()

    def test_pad_with_non_constant_padding_modes(self):
        """Unit tests for edge, reflect, symmetric padding"""
        img = torch.zeros(3, 27, 27).byte()
        img[:, :, 0] = 1  # Constant value added to leftmost edge
        img = transforms.ToPILImage()(img)
        img = F.pad(img, 1, (200, 200, 200))

        # pad 3 to all sidess
        edge_padded_img = F.pad(img, 3, padding_mode="edge")
        # First 6 elements of leftmost edge in the middle of the image, values are in order:
        # edge_pad, edge_pad, edge_pad, constant_pad, constant value added to leftmost edge, 0
        edge_middle_slice = np.asarray(edge_padded_img).transpose(2, 0, 1)[0][17][:6]
        assert_equal(edge_middle_slice, np.asarray([200, 200, 200, 200, 1, 0], dtype=np.uint8))
        assert transforms.PILToTensor()(edge_padded_img).size() == (3, 35, 35)

        # Pad 3 to left/right, 2 to top/bottom
        reflect_padded_img = F.pad(img, (3, 2), padding_mode="reflect")
        # First 6 elements of leftmost edge in the middle of the image, values are in order:
        # reflect_pad, reflect_pad, reflect_pad, constant_pad, constant value added to leftmost edge, 0
        reflect_middle_slice = np.asarray(reflect_padded_img).transpose(2, 0, 1)[0][17][:6]
        assert_equal(reflect_middle_slice, np.asarray([0, 0, 1, 200, 1, 0], dtype=np.uint8))
        assert transforms.PILToTensor()(reflect_padded_img).size() == (3, 33, 35)

        # Pad 3 to left, 2 to top, 2 to right, 1 to bottom
        symmetric_padded_img = F.pad(img, (3, 2, 2, 1), padding_mode="symmetric")
        # First 6 elements of leftmost edge in the middle of the image, values are in order:
        # sym_pad, sym_pad, sym_pad, constant_pad, constant value added to leftmost edge, 0
        symmetric_middle_slice = np.asarray(symmetric_padded_img).transpose(2, 0, 1)[0][17][:6]
        assert_equal(symmetric_middle_slice, np.asarray([0, 1, 200, 200, 1, 0], dtype=np.uint8))
        assert transforms.PILToTensor()(symmetric_padded_img).size() == (3, 32, 34)

        # Check negative padding explicitly for symmetric case, since it is not
        # implemented for tensor case to compare to
        # Crop 1 to left, pad 2 to top, pad 3 to right, crop 3 to bottom
        symmetric_padded_img_neg = F.pad(img, (-1, 2, 3, -3), padding_mode="symmetric")
        symmetric_neg_middle_left = np.asarray(symmetric_padded_img_neg).transpose(2, 0, 1)[0][17][:3]
        symmetric_neg_middle_right = np.asarray(symmetric_padded_img_neg).transpose(2, 0, 1)[0][17][-4:]
        assert_equal(symmetric_neg_middle_left, np.asarray([1, 0, 0], dtype=np.uint8))
        assert_equal(symmetric_neg_middle_right, np.asarray([200, 200, 0, 0], dtype=np.uint8))
        assert transforms.PILToTensor()(symmetric_padded_img_neg).size() == (3, 28, 31)

    def test_pad_raises_with_invalid_pad_sequence_len(self):
        with pytest.raises(ValueError):
            transforms.Pad(())

        with pytest.raises(ValueError):
            transforms.Pad((1, 2, 3))

        with pytest.raises(ValueError):
            transforms.Pad((1, 2, 3, 4, 5))

    def test_pad_with_mode_F_images(self):
        pad = 2
        transform = transforms.Pad(pad)

        img = Image.new("F", (10, 10))
        padded_img = transform(img)
        assert_equal(padded_img.size, [edge_size + 2 * pad for edge_size in img.size])


@pytest.mark.parametrize(
    "fn, trans, kwargs",
    [
        (F.invert, transforms.RandomInvert, {}),
        (F.posterize, transforms.RandomPosterize, {"bits": 4}),
        (F.solarize, transforms.RandomSolarize, {"threshold": 192}),
        (F.adjust_sharpness, transforms.RandomAdjustSharpness, {"sharpness_factor": 2.0}),
        (F.autocontrast, transforms.RandomAutocontrast, {}),
        (F.equalize, transforms.RandomEqualize, {}),
        (F.vflip, transforms.RandomVerticalFlip, {}),
        (F.hflip, transforms.RandomHorizontalFlip, {}),
        (partial(F.to_grayscale, num_output_channels=3), transforms.RandomGrayscale, {}),
    ],
)
@pytest.mark.parametrize("seed", range(10))
@pytest.mark.parametrize("p", (0, 1))
def test_randomness(fn, trans, kwargs, seed, p):
    torch.manual_seed(seed)
    img = transforms.ToPILImage()(torch.rand(3, 16, 18))

    expected_transformed_img = fn(img, **kwargs)
    randomly_transformed_img = trans(p=p, **kwargs)(img)

    if p == 0:
        assert randomly_transformed_img == img
    elif p == 1:
        assert randomly_transformed_img == expected_transformed_img

    trans(**kwargs).__repr__()


def test_autocontrast_equal_minmax():
    img_tensor = torch.tensor([[[10]], [[128]], [[245]]], dtype=torch.uint8).expand(3, 32, 32)
    img_pil = F.to_pil_image(img_tensor)

    img_tensor = F.autocontrast(img_tensor)
    img_pil = F.autocontrast(img_pil)
    torch.testing.assert_close(img_tensor, F.pil_to_tensor(img_pil))


class TestToPil:
    def _get_1_channel_tensor_various_types():
        img_data_float = torch.Tensor(1, 4, 4).uniform_()
        expected_output = img_data_float.mul(255).int().float().div(255).numpy()
        yield img_data_float, expected_output, "L"

        img_data_byte = torch.ByteTensor(1, 4, 4).random_(0, 255)
        expected_output = img_data_byte.float().div(255.0).numpy()
        yield img_data_byte, expected_output, "L"

        img_data_short = torch.ShortTensor(1, 4, 4).random_()
        expected_output = img_data_short.numpy()
        yield img_data_short, expected_output, "I;16"

        img_data_int = torch.IntTensor(1, 4, 4).random_()
        expected_output = img_data_int.numpy()
        yield img_data_int, expected_output, "I"

    def _get_2d_tensor_various_types():
        img_data_float = torch.Tensor(4, 4).uniform_()
        expected_output = img_data_float.mul(255).int().float().div(255).numpy()
        yield img_data_float, expected_output, "L"

        img_data_byte = torch.ByteTensor(4, 4).random_(0, 255)
        expected_output = img_data_byte.float().div(255.0).numpy()
        yield img_data_byte, expected_output, "L"

        img_data_short = torch.ShortTensor(4, 4).random_()
        expected_output = img_data_short.numpy()
        yield img_data_short, expected_output, "I;16"

        img_data_int = torch.IntTensor(4, 4).random_()
        expected_output = img_data_int.numpy()
        yield img_data_int, expected_output, "I"

    @pytest.mark.parametrize("with_mode", [False, True])
    @pytest.mark.parametrize("img_data, expected_output, expected_mode", _get_1_channel_tensor_various_types())
    def test_1_channel_tensor_to_pil_image(self, with_mode, img_data, expected_output, expected_mode):
        transform = transforms.ToPILImage(mode=expected_mode) if with_mode else transforms.ToPILImage()
        to_tensor = transforms.ToTensor()

        img = transform(img_data)
        assert img.mode == expected_mode
        torch.testing.assert_close(expected_output, to_tensor(img).numpy())

    def test_1_channel_float_tensor_to_pil_image(self):
        img_data = torch.Tensor(1, 4, 4).uniform_()
        # 'F' mode for torch.FloatTensor
        img_F_mode = transforms.ToPILImage(mode="F")(img_data)
        assert img_F_mode.mode == "F"
        torch.testing.assert_close(
            np.array(Image.fromarray(img_data.squeeze(0).numpy(), mode="F")), np.array(img_F_mode)
        )

    @pytest.mark.parametrize("with_mode", [False, True])
    @pytest.mark.parametrize(
        "img_data, expected_mode",
        [
            (torch.Tensor(4, 4, 1).uniform_().numpy(), "F"),
            (torch.ByteTensor(4, 4, 1).random_(0, 255).numpy(), "L"),
            (torch.ShortTensor(4, 4, 1).random_().numpy(), "I;16"),
            (torch.IntTensor(4, 4, 1).random_().numpy(), "I"),
        ],
    )
    def test_1_channel_ndarray_to_pil_image(self, with_mode, img_data, expected_mode):
        transform = transforms.ToPILImage(mode=expected_mode) if with_mode else transforms.ToPILImage()
        img = transform(img_data)
        assert img.mode == expected_mode
        # note: we explicitly convert img's dtype because pytorch doesn't support uint16
        # and otherwise assert_close wouldn't be able to construct a tensor from the uint16 array
        torch.testing.assert_close(img_data[:, :, 0], np.asarray(img).astype(img_data.dtype))

    @pytest.mark.parametrize("expected_mode", [None, "LA"])
    def test_2_channel_ndarray_to_pil_image(self, expected_mode):
        img_data = torch.ByteTensor(4, 4, 2).random_(0, 255).numpy()

        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "LA"  # default should assume LA
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode
        split = img.split()
        for i in range(2):
            torch.testing.assert_close(img_data[:, :, i], np.asarray(split[i]))

    def test_2_channel_ndarray_to_pil_image_error(self):
        img_data = torch.ByteTensor(4, 4, 2).random_(0, 255).numpy()
        transforms.ToPILImage().__repr__()

        # should raise if we try a mode for 4 or 1 or 3 channel images
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="RGBA")(img_data)
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="RGB")(img_data)

    @pytest.mark.parametrize("expected_mode", [None, "LA"])
    def test_2_channel_tensor_to_pil_image(self, expected_mode):
        img_data = torch.Tensor(2, 4, 4).uniform_()
        expected_output = img_data.mul(255).int().float().div(255)
        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "LA"  # default should assume LA
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode

        split = img.split()
        for i in range(2):
            torch.testing.assert_close(expected_output[i].numpy(), F.to_tensor(split[i]).squeeze(0).numpy())

    def test_2_channel_tensor_to_pil_image_error(self):
        img_data = torch.Tensor(2, 4, 4).uniform_()

        # should raise if we try a mode for 4 or 1 or 3 channel images
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="RGBA")(img_data)
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=r"Only modes \['LA'\] are supported for 2D inputs"):
            transforms.ToPILImage(mode="RGB")(img_data)

    @pytest.mark.parametrize("with_mode", [False, True])
    @pytest.mark.parametrize("img_data, expected_output, expected_mode", _get_2d_tensor_various_types())
    def test_2d_tensor_to_pil_image(self, with_mode, img_data, expected_output, expected_mode):
        transform = transforms.ToPILImage(mode=expected_mode) if with_mode else transforms.ToPILImage()
        to_tensor = transforms.ToTensor()

        img = transform(img_data)
        assert img.mode == expected_mode
        torch.testing.assert_close(expected_output, to_tensor(img).numpy()[0])

    @pytest.mark.parametrize("with_mode", [False, True])
    @pytest.mark.parametrize(
        "img_data, expected_mode",
        [
            (torch.Tensor(4, 4).uniform_().numpy(), "F"),
            (torch.ByteTensor(4, 4).random_(0, 255).numpy(), "L"),
            (torch.ShortTensor(4, 4).random_().numpy(), "I;16"),
            (torch.IntTensor(4, 4).random_().numpy(), "I"),
        ],
    )
    def test_2d_ndarray_to_pil_image(self, with_mode, img_data, expected_mode):
        transform = transforms.ToPILImage(mode=expected_mode) if with_mode else transforms.ToPILImage()
        img = transform(img_data)
        assert img.mode == expected_mode
        np.testing.assert_allclose(img_data, img)

    @pytest.mark.parametrize("expected_mode", [None, "RGB", "HSV", "YCbCr"])
    def test_3_channel_tensor_to_pil_image(self, expected_mode):
        img_data = torch.Tensor(3, 4, 4).uniform_()
        expected_output = img_data.mul(255).int().float().div(255)

        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "RGB"  # default should assume RGB
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode
        split = img.split()
        for i in range(3):
            torch.testing.assert_close(expected_output[i].numpy(), F.to_tensor(split[i]).squeeze(0).numpy())

    def test_3_channel_tensor_to_pil_image_error(self):
        img_data = torch.Tensor(3, 4, 4).uniform_()
        error_message_3d = r"Only modes \['RGB', 'YCbCr', 'HSV'\] are supported for 3D inputs"
        # should raise if we try a mode for 4 or 1 or 2 channel images
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="RGBA")(img_data)
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="LA")(img_data)

        with pytest.raises(ValueError, match=r"pic should be 2/3 dimensional. Got \d+ dimensions."):
            transforms.ToPILImage()(torch.Tensor(1, 3, 4, 4).uniform_())

    @pytest.mark.parametrize("expected_mode", [None, "RGB", "HSV", "YCbCr"])
    def test_3_channel_ndarray_to_pil_image(self, expected_mode):
        img_data = torch.ByteTensor(4, 4, 3).random_(0, 255).numpy()

        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "RGB"  # default should assume RGB
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode
        split = img.split()
        for i in range(3):
            torch.testing.assert_close(img_data[:, :, i], np.asarray(split[i]))

    def test_3_channel_ndarray_to_pil_image_error(self):
        img_data = torch.ByteTensor(4, 4, 3).random_(0, 255).numpy()

        # Checking if ToPILImage can be printed as string
        transforms.ToPILImage().__repr__()

        error_message_3d = r"Only modes \['RGB', 'YCbCr', 'HSV'\] are supported for 3D inputs"
        # should raise if we try a mode for 4 or 1 or 2 channel images
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="RGBA")(img_data)
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=error_message_3d):
            transforms.ToPILImage(mode="LA")(img_data)

    @pytest.mark.parametrize("expected_mode", [None, "RGBA", "CMYK", "RGBX"])
    def test_4_channel_tensor_to_pil_image(self, expected_mode):
        img_data = torch.Tensor(4, 4, 4).uniform_()
        expected_output = img_data.mul(255).int().float().div(255)

        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "RGBA"  # default should assume RGBA
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode

        split = img.split()
        for i in range(4):
            torch.testing.assert_close(expected_output[i].numpy(), F.to_tensor(split[i]).squeeze(0).numpy())

    def test_4_channel_tensor_to_pil_image_error(self):
        img_data = torch.Tensor(4, 4, 4).uniform_()

        error_message_4d = r"Only modes \['RGBA', 'CMYK', 'RGBX'\] are supported for 4D inputs"
        # should raise if we try a mode for 3 or 1 or 2 channel images
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="RGB")(img_data)
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="LA")(img_data)

    @pytest.mark.parametrize("expected_mode", [None, "RGBA", "CMYK", "RGBX"])
    def test_4_channel_ndarray_to_pil_image(self, expected_mode):
        img_data = torch.ByteTensor(4, 4, 4).random_(0, 255).numpy()

        if expected_mode is None:
            img = transforms.ToPILImage()(img_data)
            assert img.mode == "RGBA"  # default should assume RGBA
        else:
            img = transforms.ToPILImage(mode=expected_mode)(img_data)
            assert img.mode == expected_mode
        split = img.split()
        for i in range(4):
            torch.testing.assert_close(img_data[:, :, i], np.asarray(split[i]))

    def test_4_channel_ndarray_to_pil_image_error(self):
        img_data = torch.ByteTensor(4, 4, 4).random_(0, 255).numpy()

        error_message_4d = r"Only modes \['RGBA', 'CMYK', 'RGBX'\] are supported for 4D inputs"
        # should raise if we try a mode for 3 or 1 or 2 channel images
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="RGB")(img_data)
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="P")(img_data)
        with pytest.raises(ValueError, match=error_message_4d):
            transforms.ToPILImage(mode="LA")(img_data)

    def test_ndarray_bad_types_to_pil_image(self):
        trans = transforms.ToPILImage()
        reg_msg = r"Input type \w+ is not supported"
        with pytest.raises(TypeError, match=reg_msg):
            trans(np.ones([4, 4, 1], np.int64))
        with pytest.raises(TypeError, match=reg_msg):
            trans(np.ones([4, 4, 1], np.uint16))
        with pytest.raises(TypeError, match=reg_msg):
            trans(np.ones([4, 4, 1], np.uint32))
        with pytest.raises(TypeError, match=reg_msg):
            trans(np.ones([4, 4, 1], np.float64))

        with pytest.raises(ValueError, match=r"pic should be 2/3 dimensional. Got \d+ dimensions."):
            transforms.ToPILImage()(np.ones([1, 4, 4, 3]))
        with pytest.raises(ValueError, match=r"pic should not have > 4 channels. Got \d+ channels."):
            transforms.ToPILImage()(np.ones([4, 4, 6]))

    def test_tensor_bad_types_to_pil_image(self):
        with pytest.raises(ValueError, match=r"pic should be 2/3 dimensional. Got \d+ dimensions."):
            transforms.ToPILImage()(torch.ones(1, 3, 4, 4))
        with pytest.raises(ValueError, match=r"pic should not have > 4 channels. Got \d+ channels."):
            transforms.ToPILImage()(torch.ones(6, 4, 4))


def test_adjust_brightness():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    # test 0
    y_pil = F.adjust_brightness(x_pil, 1)
    y_np = np.array(y_pil)
    torch.testing.assert_close(y_np, x_np)

    # test 1
    y_pil = F.adjust_brightness(x_pil, 0.5)
    y_np = np.array(y_pil)
    y_ans = [0, 2, 6, 27, 67, 113, 18, 4, 117, 45, 127, 0]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_brightness(x_pil, 2)
    y_np = np.array(y_pil)
    y_ans = [0, 10, 26, 108, 255, 255, 74, 16, 255, 180, 255, 2]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)


def test_adjust_contrast():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    # test 0
    y_pil = F.adjust_contrast(x_pil, 1)
    y_np = np.array(y_pil)
    torch.testing.assert_close(y_np, x_np)

    # test 1
    y_pil = F.adjust_contrast(x_pil, 0.5)
    y_np = np.array(y_pil)
    y_ans = [43, 45, 49, 70, 110, 156, 61, 47, 160, 88, 170, 43]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_contrast(x_pil, 2)
    y_np = np.array(y_pil)
    y_ans = [0, 0, 0, 22, 184, 255, 0, 0, 255, 94, 255, 0]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)


@pytest.mark.skipif(Image.__version__ >= "7", reason="Temporarily disabled")
def test_adjust_saturation():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    # test 0
    y_pil = F.adjust_saturation(x_pil, 1)
    y_np = np.array(y_pil)
    torch.testing.assert_close(y_np, x_np)

    # test 1
    y_pil = F.adjust_saturation(x_pil, 0.5)
    y_np = np.array(y_pil)
    y_ans = [2, 4, 8, 87, 128, 173, 39, 25, 138, 133, 215, 88]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_saturation(x_pil, 2)
    y_np = np.array(y_pil)
    y_ans = [0, 6, 22, 0, 149, 255, 32, 0, 255, 4, 255, 0]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)


def test_adjust_hue():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    with pytest.raises(ValueError):
        F.adjust_hue(x_pil, -0.7)
        F.adjust_hue(x_pil, 1)

    # test 0: almost same as x_data but not exact.
    # probably because hsv <-> rgb floating point ops
    y_pil = F.adjust_hue(x_pil, 0)
    y_np = np.array(y_pil)
    y_ans = [0, 5, 13, 54, 139, 226, 35, 8, 234, 91, 255, 1]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 1
    y_pil = F.adjust_hue(x_pil, 0.25)
    y_np = np.array(y_pil)
    y_ans = [13, 0, 12, 224, 54, 226, 234, 8, 99, 1, 222, 255]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_hue(x_pil, -0.25)
    y_np = np.array(y_pil)
    y_ans = [0, 13, 2, 54, 226, 58, 8, 234, 152, 255, 43, 1]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)


def test_adjust_sharpness():
    x_shape = [4, 4, 3]
    x_data = [
        75,
        121,
        114,
        105,
        97,
        107,
        105,
        32,
        66,
        111,
        117,
        114,
        99,
        104,
        97,
        0,
        0,
        65,
        108,
        101,
        120,
        97,
        110,
        100,
        101,
        114,
        32,
        86,
        114,
        121,
        110,
        105,
        111,
        116,
        105,
        115,
        0,
        0,
        73,
        32,
        108,
        111,
        118,
        101,
        32,
        121,
        111,
        117,
    ]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    # test 0
    y_pil = F.adjust_sharpness(x_pil, 1)
    y_np = np.array(y_pil)
    torch.testing.assert_close(y_np, x_np)

    # test 1
    y_pil = F.adjust_sharpness(x_pil, 0.5)
    y_np = np.array(y_pil)
    y_ans = [
        75,
        121,
        114,
        105,
        97,
        107,
        105,
        32,
        66,
        111,
        117,
        114,
        99,
        104,
        97,
        30,
        30,
        74,
        103,
        96,
        114,
        97,
        110,
        100,
        101,
        114,
        32,
        81,
        103,
        108,
        102,
        101,
        107,
        116,
        105,
        115,
        0,
        0,
        73,
        32,
        108,
        111,
        118,
        101,
        32,
        121,
        111,
        117,
    ]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_sharpness(x_pil, 2)
    y_np = np.array(y_pil)
    y_ans = [
        75,
        121,
        114,
        105,
        97,
        107,
        105,
        32,
        66,
        111,
        117,
        114,
        99,
        104,
        97,
        0,
        0,
        46,
        118,
        111,
        132,
        97,
        110,
        100,
        101,
        114,
        32,
        95,
        135,
        146,
        126,
        112,
        119,
        116,
        105,
        115,
        0,
        0,
        73,
        32,
        108,
        111,
        118,
        101,
        32,
        121,
        111,
        117,
    ]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 3
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")
    x_th = torch.tensor(x_np.transpose(2, 0, 1))
    y_pil = F.adjust_sharpness(x_pil, 2)
    y_np = np.array(y_pil).transpose(2, 0, 1)
    y_th = F.adjust_sharpness(x_th, 2)
    torch.testing.assert_close(y_np, y_th.numpy())


def test_adjust_gamma():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")

    # test 0
    y_pil = F.adjust_gamma(x_pil, 1)
    y_np = np.array(y_pil)
    torch.testing.assert_close(y_np, x_np)

    # test 1
    y_pil = F.adjust_gamma(x_pil, 0.5)
    y_np = np.array(y_pil)
    y_ans = [0, 35, 57, 117, 186, 241, 97, 45, 245, 152, 255, 16]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)

    # test 2
    y_pil = F.adjust_gamma(x_pil, 2)
    y_np = np.array(y_pil)
    y_ans = [0, 0, 0, 11, 71, 201, 5, 0, 215, 31, 255, 0]
    y_ans = np.array(y_ans, dtype=np.uint8).reshape(x_shape)
    torch.testing.assert_close(y_np, y_ans)


def test_adjusts_L_mode():
    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_rgb = Image.fromarray(x_np, mode="RGB")

    x_l = x_rgb.convert("L")
    assert F.adjust_brightness(x_l, 2).mode == "L"
    assert F.adjust_saturation(x_l, 2).mode == "L"
    assert F.adjust_contrast(x_l, 2).mode == "L"
    assert F.adjust_hue(x_l, 0.4).mode == "L"
    assert F.adjust_sharpness(x_l, 2).mode == "L"
    assert F.adjust_gamma(x_l, 0.5).mode == "L"


def test_rotate():
    x = np.zeros((100, 100, 3), dtype=np.uint8)
    x[40, 40] = [255, 255, 255]

    with pytest.raises(TypeError, match=r"img should be PIL Image"):
        F.rotate(x, 10)

    img = F.to_pil_image(x)

    result = F.rotate(img, 45)
    assert result.size == (100, 100)
    r, c, ch = np.where(result)
    assert all(x in r for x in [49, 50])
    assert all(x in c for x in [36])
    assert all(x in ch for x in [0, 1, 2])

    result = F.rotate(img, 45, expand=True)
    assert result.size == (142, 142)
    r, c, ch = np.where(result)
    assert all(x in r for x in [70, 71])
    assert all(x in c for x in [57])
    assert all(x in ch for x in [0, 1, 2])

    result = F.rotate(img, 45, center=(40, 40))
    assert result.size == (100, 100)
    r, c, ch = np.where(result)
    assert all(x in r for x in [40])
    assert all(x in c for x in [40])
    assert all(x in ch for x in [0, 1, 2])

    result_a = F.rotate(img, 90)
    result_b = F.rotate(img, -270)

    assert_equal(np.array(result_a), np.array(result_b))


@pytest.mark.parametrize("mode", ["L", "RGB", "F"])
def test_rotate_fill(mode):
    img = F.to_pil_image(np.ones((100, 100, 3), dtype=np.uint8) * 255, "RGB")

    num_bands = len(mode)
    wrong_num_bands = num_bands + 1
    fill = 127

    img_conv = img.convert(mode)
    img_rot = F.rotate(img_conv, 45.0, fill=fill)
    pixel = img_rot.getpixel((0, 0))

    if not isinstance(pixel, tuple):
        pixel = (pixel,)
    assert pixel == tuple([fill] * num_bands)

    with pytest.raises(ValueError):
        F.rotate(img_conv, 45.0, fill=tuple([fill] * wrong_num_bands))


def test_gaussian_blur_asserts():
    np_img = np.ones((100, 100, 3), dtype=np.uint8) * 255
    img = F.to_pil_image(np_img, "RGB")

    with pytest.raises(ValueError, match=r"If kernel_size is a sequence its length should be 2"):
        F.gaussian_blur(img, [3])
    with pytest.raises(ValueError, match=r"If kernel_size is a sequence its length should be 2"):
        F.gaussian_blur(img, [3, 3, 3])
    with pytest.raises(ValueError, match=r"Kernel size should be a tuple/list of two integers"):
        transforms.GaussianBlur([3, 3, 3])

    with pytest.raises(ValueError, match=r"kernel_size should have odd and positive integers"):
        F.gaussian_blur(img, [4, 4])
    with pytest.raises(ValueError, match=r"Kernel size value should be an odd and positive number"):
        transforms.GaussianBlur([4, 4])

    with pytest.raises(ValueError, match=r"kernel_size should have odd and positive integers"):
        F.gaussian_blur(img, [-3, -3])
    with pytest.raises(ValueError, match=r"Kernel size value should be an odd and positive number"):
        transforms.GaussianBlur([-3, -3])

    with pytest.raises(ValueError, match=r"If sigma is a sequence, its length should be 2"):
        F.gaussian_blur(img, 3, [1, 1, 1])
    with pytest.raises(ValueError, match=r"sigma should be a single number or a list/tuple with length 2"):
        transforms.GaussianBlur(3, [1, 1, 1])

    with pytest.raises(ValueError, match=r"sigma should have positive values"):
        F.gaussian_blur(img, 3, -1.0)
    with pytest.raises(ValueError, match=r"If sigma is a single number, it must be positive"):
        transforms.GaussianBlur(3, -1.0)

    with pytest.raises(TypeError, match=r"kernel_size should be int or a sequence of integers"):
        F.gaussian_blur(img, "kernel_size_string")
    with pytest.raises(ValueError, match=r"Kernel size should be a tuple/list of two integers"):
        transforms.GaussianBlur("kernel_size_string")

    with pytest.raises(TypeError, match=r"sigma should be either float or sequence of floats"):
        F.gaussian_blur(img, 3, "sigma_string")
    with pytest.raises(ValueError, match=r"sigma should be a single number or a list/tuple with length 2"):
        transforms.GaussianBlur(3, "sigma_string")


def test_lambda():
    trans = transforms.Lambda(lambda x: x.add(10))
    x = torch.randn(10)
    y = trans(x)
    assert_equal(y, torch.add(x, 10))

    trans = transforms.Lambda(lambda x: x.add_(10))
    x = torch.randn(10)
    y = trans(x)
    assert_equal(y, x)

    # Checking if Lambda can be printed as string
    trans.__repr__()


def test_to_grayscale():
    """Unit tests for grayscale transform"""

    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")
    x_pil_2 = x_pil.convert("L")
    gray_np = np.array(x_pil_2)

    # Test Set: Grayscale an image with desired number of output channels
    # Case 1: RGB -> 1 channel grayscale
    trans1 = transforms.Grayscale(num_output_channels=1)
    gray_pil_1 = trans1(x_pil)
    gray_np_1 = np.array(gray_pil_1)
    assert gray_pil_1.mode == "L", "mode should be L"
    assert gray_np_1.shape == tuple(x_shape[0:2]), "should be 1 channel"
    assert_equal(gray_np, gray_np_1)

    # Case 2: RGB -> 3 channel grayscale
    trans2 = transforms.Grayscale(num_output_channels=3)
    gray_pil_2 = trans2(x_pil)
    gray_np_2 = np.array(gray_pil_2)
    assert gray_pil_2.mode == "RGB", "mode should be RGB"
    assert gray_np_2.shape == tuple(x_shape), "should be 3 channel"
    assert_equal(gray_np_2[:, :, 0], gray_np_2[:, :, 1])
    assert_equal(gray_np_2[:, :, 1], gray_np_2[:, :, 2])
    assert_equal(gray_np, gray_np_2[:, :, 0])

    # Case 3: 1 channel grayscale -> 1 channel grayscale
    trans3 = transforms.Grayscale(num_output_channels=1)
    gray_pil_3 = trans3(x_pil_2)
    gray_np_3 = np.array(gray_pil_3)
    assert gray_pil_3.mode == "L", "mode should be L"
    assert gray_np_3.shape == tuple(x_shape[0:2]), "should be 1 channel"
    assert_equal(gray_np, gray_np_3)

    # Case 4: 1 channel grayscale -> 3 channel grayscale
    trans4 = transforms.Grayscale(num_output_channels=3)
    gray_pil_4 = trans4(x_pil_2)
    gray_np_4 = np.array(gray_pil_4)
    assert gray_pil_4.mode == "RGB", "mode should be RGB"
    assert gray_np_4.shape == tuple(x_shape), "should be 3 channel"
    assert_equal(gray_np_4[:, :, 0], gray_np_4[:, :, 1])
    assert_equal(gray_np_4[:, :, 1], gray_np_4[:, :, 2])
    assert_equal(gray_np, gray_np_4[:, :, 0])

    # Checking if Grayscale can be printed as string
    trans4.__repr__()


@pytest.mark.parametrize("seed", range(10))
@pytest.mark.parametrize("p", (0, 1))
def test_random_apply(p, seed):
    torch.manual_seed(seed)
    random_apply_transform = transforms.RandomApply([transforms.RandomRotation((45, 50))], p=p)
    img = transforms.ToPILImage()(torch.rand(3, 30, 40))
    out = random_apply_transform(img)
    if p == 0:
        assert out == img
    elif p == 1:
        assert out != img

    # Checking if RandomApply can be printed as string
    random_apply_transform.__repr__()


@pytest.mark.parametrize("seed", range(10))
@pytest.mark.parametrize("proba_passthrough", (0, 1))
def test_random_choice(proba_passthrough, seed):
    random.seed(seed)  # RandomChoice relies on python builtin random.choice, not pytorch

    random_choice_transform = transforms.RandomChoice(
        [
            lambda x: x,  # passthrough
            transforms.RandomRotation((45, 50)),
        ],
        p=[proba_passthrough, 1 - proba_passthrough],
    )

    img = transforms.ToPILImage()(torch.rand(3, 30, 40))
    out = random_choice_transform(img)
    if proba_passthrough == 1:
        assert out == img
    elif proba_passthrough == 0:
        assert out != img

    # Checking if RandomChoice can be printed as string
    random_choice_transform.__repr__()


@pytest.mark.skipif(stats is None, reason="scipy.stats not available")
def test_random_order():
    random_state = random.getstate()
    random.seed(42)
    random_order_transform = transforms.RandomOrder([transforms.Resize(20, antialias=True), transforms.CenterCrop(10)])
    img = transforms.ToPILImage()(torch.rand(3, 25, 25))
    num_samples = 250
    num_normal_order = 0
    resize_crop_out = transforms.CenterCrop(10)(transforms.Resize(20, antialias=True)(img))
    for _ in range(num_samples):
        out = random_order_transform(img)
        if out == resize_crop_out:
            num_normal_order += 1

    p_value = stats.binom_test(num_normal_order, num_samples, p=0.5)
    random.setstate(random_state)
    assert p_value > 0.0001

    # Checking if RandomOrder can be printed as string
    random_order_transform.__repr__()


def test_linear_transformation():
    num_samples = 1000
    x = torch.randn(num_samples, 3, 10, 10)
    flat_x = x.view(x.size(0), x.size(1) * x.size(2) * x.size(3))
    # compute principal components
    sigma = torch.mm(flat_x.t(), flat_x) / flat_x.size(0)
    u, s, _ = np.linalg.svd(sigma.numpy())
    zca_epsilon = 1e-10  # avoid division by 0
    d = torch.Tensor(np.diag(1.0 / np.sqrt(s + zca_epsilon)))
    u = torch.Tensor(u)
    principal_components = torch.mm(torch.mm(u, d), u.t())
    mean_vector = torch.sum(flat_x, dim=0) / flat_x.size(0)
    # initialize whitening matrix
    whitening = transforms.LinearTransformation(principal_components, mean_vector)
    # estimate covariance and mean using weak law of large number
    num_features = flat_x.size(1)
    cov = 0.0
    mean = 0.0
    for i in x:
        xwhite = whitening(i)
        xwhite = xwhite.view(1, -1).numpy()
        cov += np.dot(xwhite, xwhite.T) / num_features
        mean += np.sum(xwhite) / num_features
    # if rtol for std = 1e-3 then rtol for cov = 2e-3 as std**2 = cov
    torch.testing.assert_close(
        cov / num_samples, np.identity(1), rtol=2e-3, atol=1e-8, check_dtype=False, msg="cov not close to 1"
    )
    torch.testing.assert_close(
        mean / num_samples, 0, rtol=1e-3, atol=1e-8, check_dtype=False, msg="mean not close to 0"
    )

    # Checking if LinearTransformation can be printed as string
    whitening.__repr__()


@pytest.mark.parametrize("dtype", int_dtypes())
def test_max_value(dtype):

    assert F_t._max_value(dtype) == torch.iinfo(dtype).max
    # remove float testing as it can lead to errors such as
    # runtime error: 5.7896e+76 is outside the range of representable values of type 'float'
    # for dtype in float_dtypes():
    # self.assertGreater(F_t._max_value(dtype), torch.finfo(dtype).max)


@pytest.mark.xfail(
    reason="torch.iinfo() is not supported by torchscript. See https://github.com/pytorch/pytorch/issues/41492."
)
def test_max_value_iinfo():
    @torch.jit.script
    def max_value(image: torch.Tensor) -> int:
        return 1 if image.is_floating_point() else torch.iinfo(image.dtype).max


@pytest.mark.parametrize("should_vflip", [True, False])
@pytest.mark.parametrize("single_dim", [True, False])
def test_ten_crop(should_vflip, single_dim):
    to_pil_image = transforms.ToPILImage()
    h = random.randint(5, 25)
    w = random.randint(5, 25)
    crop_h = random.randint(1, h)
    crop_w = random.randint(1, w)
    if single_dim:
        crop_h = min(crop_h, crop_w)
        crop_w = crop_h
        transform = transforms.TenCrop(crop_h, vertical_flip=should_vflip)
        five_crop = transforms.FiveCrop(crop_h)
    else:
        transform = transforms.TenCrop((crop_h, crop_w), vertical_flip=should_vflip)
        five_crop = transforms.FiveCrop((crop_h, crop_w))

    img = to_pil_image(torch.FloatTensor(3, h, w).uniform_())
    results = transform(img)
    expected_output = five_crop(img)

    # Checking if FiveCrop and TenCrop can be printed as string
    transform.__repr__()
    five_crop.__repr__()

    if should_vflip:
        vflipped_img = img.transpose(Image.FLIP_TOP_BOTTOM)
        expected_output += five_crop(vflipped_img)
    else:
        hflipped_img = img.transpose(Image.FLIP_LEFT_RIGHT)
        expected_output += five_crop(hflipped_img)

    assert len(results) == 10
    assert results == expected_output


@pytest.mark.parametrize("single_dim", [True, False])
def test_five_crop(single_dim):
    to_pil_image = transforms.ToPILImage()
    h = random.randint(5, 25)
    w = random.randint(5, 25)
    crop_h = random.randint(1, h)
    crop_w = random.randint(1, w)
    if single_dim:
        crop_h = min(crop_h, crop_w)
        crop_w = crop_h
        transform = transforms.FiveCrop(crop_h)
    else:
        transform = transforms.FiveCrop((crop_h, crop_w))

    img = torch.FloatTensor(3, h, w).uniform_()

    results = transform(to_pil_image(img))

    assert len(results) == 5
    for crop in results:
        assert crop.size == (crop_w, crop_h)

    to_pil_image = transforms.ToPILImage()
    tl = to_pil_image(img[:, 0:crop_h, 0:crop_w])
    tr = to_pil_image(img[:, 0:crop_h, w - crop_w :])
    bl = to_pil_image(img[:, h - crop_h :, 0:crop_w])
    br = to_pil_image(img[:, h - crop_h :, w - crop_w :])
    center = transforms.CenterCrop((crop_h, crop_w))(to_pil_image(img))
    expected_output = (tl, tr, bl, br, center)
    assert results == expected_output


@pytest.mark.parametrize("policy", transforms.AutoAugmentPolicy)
@pytest.mark.parametrize("fill", [None, 85, (128, 128, 128)])
@pytest.mark.parametrize("grayscale", [True, False])
def test_autoaugment(policy, fill, grayscale):
    random.seed(42)
    img = Image.open(GRACE_HOPPER)
    if grayscale:
        img, fill = _get_grayscale_test_image(img, fill)
    transform = transforms.AutoAugment(policy=policy, fill=fill)
    for _ in range(100):
        img = transform(img)
    transform.__repr__()


@pytest.mark.parametrize("num_ops", [1, 2, 3])
@pytest.mark.parametrize("magnitude", [7, 9, 11])
@pytest.mark.parametrize("fill", [None, 85, (128, 128, 128)])
@pytest.mark.parametrize("grayscale", [True, False])
def test_randaugment(num_ops, magnitude, fill, grayscale):
    random.seed(42)
    img = Image.open(GRACE_HOPPER)
    if grayscale:
        img, fill = _get_grayscale_test_image(img, fill)
    transform = transforms.RandAugment(num_ops=num_ops, magnitude=magnitude, fill=fill)
    for _ in range(100):
        img = transform(img)
    transform.__repr__()


@pytest.mark.parametrize("fill", [None, 85, (128, 128, 128)])
@pytest.mark.parametrize("num_magnitude_bins", [10, 13, 30])
@pytest.mark.parametrize("grayscale", [True, False])
def test_trivialaugmentwide(fill, num_magnitude_bins, grayscale):
    random.seed(42)
    img = Image.open(GRACE_HOPPER)
    if grayscale:
        img, fill = _get_grayscale_test_image(img, fill)
    transform = transforms.TrivialAugmentWide(fill=fill, num_magnitude_bins=num_magnitude_bins)
    for _ in range(100):
        img = transform(img)
    transform.__repr__()


@pytest.mark.parametrize("fill", [None, 85, (128, 128, 128)])
@pytest.mark.parametrize("severity", [1, 10])
@pytest.mark.parametrize("mixture_width", [1, 2])
@pytest.mark.parametrize("chain_depth", [-1, 2])
@pytest.mark.parametrize("all_ops", [True, False])
@pytest.mark.parametrize("grayscale", [True, False])
def test_augmix(fill, severity, mixture_width, chain_depth, all_ops, grayscale):
    random.seed(42)
    img = Image.open(GRACE_HOPPER)
    if grayscale:
        img, fill = _get_grayscale_test_image(img, fill)
    transform = transforms.AugMix(
        fill=fill, severity=severity, mixture_width=mixture_width, chain_depth=chain_depth, all_ops=all_ops
    )
    for _ in range(100):
        img = transform(img)
    transform.__repr__()


def test_random_crop():
    height = random.randint(10, 32) * 2
    width = random.randint(10, 32) * 2
    oheight = random.randint(5, (height - 2) / 2) * 2
    owidth = random.randint(5, (width - 2) / 2) * 2
    img = torch.ones(3, height, width, dtype=torch.uint8)
    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.RandomCrop((oheight, owidth)),
            transforms.PILToTensor(),
        ]
    )(img)
    assert result.size(1) == oheight
    assert result.size(2) == owidth

    padding = random.randint(1, 20)
    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.RandomCrop((oheight, owidth), padding=padding),
            transforms.PILToTensor(),
        ]
    )(img)
    assert result.size(1) == oheight
    assert result.size(2) == owidth

    result = transforms.Compose(
        [transforms.ToPILImage(), transforms.RandomCrop((height, width)), transforms.PILToTensor()]
    )(img)
    assert result.size(1) == height
    assert result.size(2) == width
    torch.testing.assert_close(result, img)

    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.RandomCrop((height + 1, width + 1), pad_if_needed=True),
            transforms.PILToTensor(),
        ]
    )(img)
    assert result.size(1) == height + 1
    assert result.size(2) == width + 1

    t = transforms.RandomCrop(33)
    img = torch.ones(3, 32, 32)
    with pytest.raises(ValueError, match=r"Required crop size .+ is larger than input image size .+"):
        t(img)


def test_center_crop():
    height = random.randint(10, 32) * 2
    width = random.randint(10, 32) * 2
    oheight = random.randint(5, (height - 2) / 2) * 2
    owidth = random.randint(5, (width - 2) / 2) * 2

    img = torch.ones(3, height, width, dtype=torch.uint8)
    oh1 = (height - oheight) // 2
    ow1 = (width - owidth) // 2
    imgnarrow = img[:, oh1 : oh1 + oheight, ow1 : ow1 + owidth]
    imgnarrow.fill_(0)
    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.CenterCrop((oheight, owidth)),
            transforms.PILToTensor(),
        ]
    )(img)
    assert result.sum() == 0
    oheight += 1
    owidth += 1
    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.CenterCrop((oheight, owidth)),
            transforms.PILToTensor(),
        ]
    )(img)
    sum1 = result.sum()
    assert sum1 > 1
    oheight += 1
    owidth += 1
    result = transforms.Compose(
        [
            transforms.ToPILImage(),
            transforms.CenterCrop((oheight, owidth)),
            transforms.PILToTensor(),
        ]
    )(img)
    sum2 = result.sum()
    assert sum2 > 0
    assert sum2 > sum1


@pytest.mark.parametrize("odd_image_size", (True, False))
@pytest.mark.parametrize("delta", (1, 3, 5))
@pytest.mark.parametrize("delta_width", (-2, -1, 0, 1, 2))
@pytest.mark.parametrize("delta_height", (-2, -1, 0, 1, 2))
def test_center_crop_2(odd_image_size, delta, delta_width, delta_height):
    """Tests when center crop size is larger than image size, along any dimension"""

    # Since height is independent of width, we can ignore images with odd height and even width and vice-versa.
    input_image_size = (random.randint(10, 32) * 2, random.randint(10, 32) * 2)
    if odd_image_size:
        input_image_size = (input_image_size[0] + 1, input_image_size[1] + 1)

    delta_height *= delta
    delta_width *= delta

    img = torch.ones(3, *input_image_size, dtype=torch.uint8)
    crop_size = (input_image_size[0] + delta_height, input_image_size[1] + delta_width)

    # Test both transforms, one with PIL input and one with tensor
    output_pil = transforms.Compose(
        [transforms.ToPILImage(), transforms.CenterCrop(crop_size), transforms.PILToTensor()],
    )(img)
    assert output_pil.size()[1:3] == crop_size

    output_tensor = transforms.CenterCrop(crop_size)(img)
    assert output_tensor.size()[1:3] == crop_size

    # Ensure output for PIL and Tensor are equal
    assert_equal(
        output_tensor,
        output_pil,
        msg=f"image_size: {input_image_size} crop_size: {crop_size}",
    )

    # Check if content in center of both image and cropped output is same.
    center_size = (min(crop_size[0], input_image_size[0]), min(crop_size[1], input_image_size[1]))
    crop_center_tl, input_center_tl = [0, 0], [0, 0]
    for index in range(2):
        if crop_size[index] > input_image_size[index]:
            crop_center_tl[index] = (crop_size[index] - input_image_size[index]) // 2
        else:
            input_center_tl[index] = (input_image_size[index] - crop_size[index]) // 2

    output_center = output_pil[
        :,
        crop_center_tl[0] : crop_center_tl[0] + center_size[0],
        crop_center_tl[1] : crop_center_tl[1] + center_size[1],
    ]

    img_center = img[
        :,
        input_center_tl[0] : input_center_tl[0] + center_size[0],
        input_center_tl[1] : input_center_tl[1] + center_size[1],
    ]

    assert_equal(output_center, img_center)


def test_color_jitter():
    color_jitter = transforms.ColorJitter(2, 2, 2, 0.1)

    x_shape = [2, 2, 3]
    x_data = [0, 5, 13, 54, 135, 226, 37, 8, 234, 90, 255, 1]
    x_np = np.array(x_data, dtype=np.uint8).reshape(x_shape)
    x_pil = Image.fromarray(x_np, mode="RGB")
    x_pil_2 = x_pil.convert("L")

    for _ in range(10):
        y_pil = color_jitter(x_pil)
        assert y_pil.mode == x_pil.mode

        y_pil_2 = color_jitter(x_pil_2)
        assert y_pil_2.mode == x_pil_2.mode

    # Checking if ColorJitter can be printed as string
    color_jitter.__repr__()


@pytest.mark.parametrize("hue", [1, (-1, 1)])
def test_color_jitter_hue_out_of_bounds(hue):
    with pytest.raises(ValueError, match=re.escape("hue values should be between (-0.5, 0.5)")):
        transforms.ColorJitter(hue=hue)


@pytest.mark.parametrize("seed", range(10))
@pytest.mark.skipif(stats is None, reason="scipy.stats not available")
def test_random_erasing(seed):
    torch.random.manual_seed(seed)
    img = torch.ones(3, 128, 128)

    t = transforms.RandomErasing(scale=(0.1, 0.1), ratio=(1 / 3, 3.0))
    y, x, h, w, v = t.get_params(
        img,
        t.scale,
        t.ratio,
        [
            t.value,
        ],
    )
    aspect_ratio = h / w
    # Add some tolerance due to the rounding and int conversion used in the transform
    tol = 0.05
    assert 1 / 3 - tol <= aspect_ratio <= 3 + tol

    # Make sure that h > w and h < w are equally likely (log-scale sampling)
    aspect_ratios = []
    random.seed(42)
    trial = 1000
    for _ in range(trial):
        y, x, h, w, v = t.get_params(
            img,
            t.scale,
            t.ratio,
            [
                t.value,
            ],
        )
        aspect_ratios.append(h / w)

    count_bigger_then_ones = len([1 for aspect_ratio in aspect_ratios if aspect_ratio > 1])
    p_value = stats.binom_test(count_bigger_then_ones, trial, p=0.5)
    assert p_value > 0.0001

    # Checking if RandomErasing can be printed as string
    t.__repr__()


def test_random_rotation():

    with pytest.raises(ValueError):
        transforms.RandomRotation(-0.7)

    with pytest.raises(ValueError):
        transforms.RandomRotation([-0.7])

    with pytest.raises(ValueError):
        transforms.RandomRotation([-0.7, 0, 0.7])

    t = transforms.RandomRotation(0, fill=None)
    assert t.fill == 0

    t = transforms.RandomRotation(10)
    angle = t.get_params(t.degrees)
    assert angle > -10 and angle < 10

    t = transforms.RandomRotation((-10, 10))
    angle = t.get_params(t.degrees)
    assert -10 < angle < 10

    # Checking if RandomRotation can be printed as string
    t.__repr__()

    t = transforms.RandomRotation((-10, 10), interpolation=Image.BILINEAR)
    assert t.interpolation == transforms.InterpolationMode.BILINEAR


def test_random_rotation_error():
    # assert fill being either a Sequence or a Number
    with pytest.raises(TypeError):
        transforms.RandomRotation(0, fill={})


def test_randomperspective():
    for _ in range(10):
        height = random.randint(24, 32) * 2
        width = random.randint(24, 32) * 2
        img = torch.ones(3, height, width)
        to_pil_image = transforms.ToPILImage()
        img = to_pil_image(img)
        perp = transforms.RandomPerspective()
        startpoints, endpoints = perp.get_params(width, height, 0.5)
        tr_img = F.perspective(img, startpoints, endpoints)
        tr_img2 = F.convert_image_dtype(F.pil_to_tensor(F.perspective(tr_img, endpoints, startpoints)))
        tr_img = F.convert_image_dtype(F.pil_to_tensor(tr_img))
        assert img.size[0] == width
        assert img.size[1] == height
        assert torch.nn.functional.mse_loss(
            tr_img, F.convert_image_dtype(F.pil_to_tensor(img))
        ) + 0.3 > torch.nn.functional.mse_loss(tr_img2, F.convert_image_dtype(F.pil_to_tensor(img)))


@pytest.mark.parametrize("seed", range(10))
@pytest.mark.parametrize("mode", ["L", "RGB", "F"])
def test_randomperspective_fill(mode, seed):
    torch.random.manual_seed(seed)

    # assert fill being either a Sequence or a Number
    with pytest.raises(TypeError):
        transforms.RandomPerspective(fill={})

    t = transforms.RandomPerspective(fill=None)
    assert t.fill == 0

    height = 100
    width = 100
    img = torch.ones(3, height, width)
    to_pil_image = transforms.ToPILImage()
    img = to_pil_image(img)
    fill = 127
    num_bands = len(mode)

    img_conv = img.convert(mode)
    perspective = transforms.RandomPerspective(p=1, fill=fill)
    tr_img = perspective(img_conv)
    pixel = tr_img.getpixel((0, 0))

    if not isinstance(pixel, tuple):
        pixel = (pixel,)
    assert pixel == tuple([fill] * num_bands)

    startpoints, endpoints = transforms.RandomPerspective.get_params(width, height, 0.5)
    tr_img = F.perspective(img_conv, startpoints, endpoints, fill=fill)
    pixel = tr_img.getpixel((0, 0))

    if not isinstance(pixel, tuple):
        pixel = (pixel,)
    assert pixel == tuple([fill] * num_bands)

    wrong_num_bands = num_bands + 1
    with pytest.raises(ValueError):
        F.perspective(img_conv, startpoints, endpoints, fill=tuple([fill] * wrong_num_bands))


@pytest.mark.skipif(stats is None, reason="scipy.stats not available")
def test_normalize():
    def samples_from_standard_normal(tensor):
        p_value = stats.kstest(list(tensor.view(-1)), "norm", args=(0, 1)).pvalue
        return p_value > 0.0001

    random_state = random.getstate()
    random.seed(42)
    for channels in [1, 3]:
        img = torch.rand(channels, 10, 10)
        mean = [img[c].mean() for c in range(channels)]
        std = [img[c].std() for c in range(channels)]
        normalized = transforms.Normalize(mean, std)(img)
        assert samples_from_standard_normal(normalized)
    random.setstate(random_state)

    # Checking if Normalize can be printed as string
    transforms.Normalize(mean, std).__repr__()

    # Checking the optional in-place behaviour
    tensor = torch.rand((1, 16, 16))
    tensor_inplace = transforms.Normalize((0.5,), (0.5,), inplace=True)(tensor)
    assert_equal(tensor, tensor_inplace)


@pytest.mark.parametrize("dtype1", [torch.float32, torch.float64])
@pytest.mark.parametrize("dtype2", [torch.int64, torch.float32, torch.float64])
def test_normalize_different_dtype(dtype1, dtype2):
    img = torch.rand(3, 10, 10, dtype=dtype1)
    mean = torch.tensor([1, 2, 3], dtype=dtype2)
    std = torch.tensor([1, 2, 1], dtype=dtype2)
    # checks that it doesn't crash
    transforms.functional.normalize(img, mean, std)


def test_normalize_3d_tensor():
    torch.manual_seed(28)
    n_channels = 3
    img_size = 10
    mean = torch.rand(n_channels)
    std = torch.rand(n_channels)
    img = torch.rand(n_channels, img_size, img_size)
    target = F.normalize(img, mean, std)

    mean_unsqueezed = mean.view(-1, 1, 1)
    std_unsqueezed = std.view(-1, 1, 1)
    result1 = F.normalize(img, mean_unsqueezed, std_unsqueezed)
    result2 = F.normalize(
        img, mean_unsqueezed.repeat(1, img_size, img_size), std_unsqueezed.repeat(1, img_size, img_size)
    )
    torch.testing.assert_close(target, result1)
    torch.testing.assert_close(target, result2)


class TestAffine:
    @pytest.fixture(scope="class")
    def input_img(self):
        input_img = np.zeros((40, 40, 3), dtype=np.uint8)
        for pt in [(16, 16), (20, 16), (20, 20)]:
            for i in range(-5, 5):
                for j in range(-5, 5):
                    input_img[pt[0] + i, pt[1] + j, :] = [255, 155, 55]
        return input_img

    def test_affine_translate_seq(self, input_img):
        with pytest.raises(TypeError, match=r"Argument translate should be a sequence"):
            F.affine(input_img, 10, translate=0, scale=1, shear=1)

    @pytest.fixture(scope="class")
    def pil_image(self, input_img):
        return F.to_pil_image(input_img)

    def _to_3x3_inv(self, inv_result_matrix):
        result_matrix = np.zeros((3, 3))
        result_matrix[:2, :] = np.array(inv_result_matrix).reshape((2, 3))
        result_matrix[2, 2] = 1
        return np.linalg.inv(result_matrix)

    def _test_transformation(self, angle, translate, scale, shear, pil_image, input_img, center=None):

        a_rad = math.radians(angle)
        s_rad = [math.radians(sh_) for sh_ in shear]
        cnt = [20, 20] if center is None else center
        cx, cy = cnt
        tx, ty = translate
        sx, sy = s_rad
        rot = a_rad

        # 1) Check transformation matrix:
        C = np.array([[1, 0, cx], [0, 1, cy], [0, 0, 1]])
        T = np.array([[1, 0, tx], [0, 1, ty], [0, 0, 1]])
        Cinv = np.linalg.inv(C)

        RS = np.array(
            [
                [scale * math.cos(rot), -scale * math.sin(rot), 0],
                [scale * math.sin(rot), scale * math.cos(rot), 0],
                [0, 0, 1],
            ]
        )

        SHx = np.array([[1, -math.tan(sx), 0], [0, 1, 0], [0, 0, 1]])

        SHy = np.array([[1, 0, 0], [-math.tan(sy), 1, 0], [0, 0, 1]])

        RSS = np.matmul(RS, np.matmul(SHy, SHx))

        true_matrix = np.matmul(T, np.matmul(C, np.matmul(RSS, Cinv)))

        result_matrix = self._to_3x3_inv(
            F._get_inverse_affine_matrix(center=cnt, angle=angle, translate=translate, scale=scale, shear=shear)
        )
        assert np.sum(np.abs(true_matrix - result_matrix)) < 1e-10
        # 2) Perform inverse mapping:
        true_result = np.zeros((40, 40, 3), dtype=np.uint8)
        inv_true_matrix = np.linalg.inv(true_matrix)
        for y in range(true_result.shape[0]):
            for x in range(true_result.shape[1]):
                # Same as for PIL:
                # https://github.com/python-pillow/Pillow/blob/71f8ec6a0cfc1008076a023c0756542539d057ab/
                # src/libImaging/Geometry.c#L1060
                input_pt = np.array([x + 0.5, y + 0.5, 1.0])
                res = np.floor(np.dot(inv_true_matrix, input_pt)).astype(int)
                _x, _y = res[:2]
                if 0 <= _x < input_img.shape[1] and 0 <= _y < input_img.shape[0]:
                    true_result[y, x, :] = input_img[_y, _x, :]

        result = F.affine(pil_image, angle=angle, translate=translate, scale=scale, shear=shear, center=center)
        assert result.size == pil_image.size
        # Compute number of different pixels:
        np_result = np.array(result)
        n_diff_pixels = np.sum(np_result != true_result) / 3
        # Accept 3 wrong pixels
        error_msg = (
            f"angle={angle}, translate={translate}, scale={scale}, shear={shear}\nn diff pixels={n_diff_pixels}\n"
        )
        assert n_diff_pixels < 3, error_msg

    def test_transformation_discrete(self, pil_image, input_img):
        # Test rotation
        angle = 45
        self._test_transformation(
            angle=angle, translate=(0, 0), scale=1.0, shear=(0.0, 0.0), pil_image=pil_image, input_img=input_img
        )

        # Test rotation
        angle = 45
        self._test_transformation(
            angle=angle,
            translate=(0, 0),
            scale=1.0,
            shear=(0.0, 0.0),
            pil_image=pil_image,
            input_img=input_img,
            center=[0, 0],
        )

        # Test translation
        translate = [10, 15]
        self._test_transformation(
            angle=0.0, translate=translate, scale=1.0, shear=(0.0, 0.0), pil_image=pil_image, input_img=input_img
        )

        # Test scale
        scale = 1.2
        self._test_transformation(
            angle=0.0, translate=(0.0, 0.0), scale=scale, shear=(0.0, 0.0), pil_image=pil_image, input_img=input_img
        )

        # Test shear
        shear = [45.0, 25.0]
        self._test_transformation(
            angle=0.0, translate=(0.0, 0.0), scale=1.0, shear=shear, pil_image=pil_image, input_img=input_img
        )

        # Test shear with top-left as center
        shear = [45.0, 25.0]
        self._test_transformation(
            angle=0.0,
            translate=(0.0, 0.0),
            scale=1.0,
            shear=shear,
            pil_image=pil_image,
            input_img=input_img,
            center=[0, 0],
        )

    @pytest.mark.parametrize("angle", range(-90, 90, 36))
    @pytest.mark.parametrize("translate", range(-10, 10, 5))
    @pytest.mark.parametrize("scale", [0.77, 1.0, 1.27])
    @pytest.mark.parametrize("shear", range(-15, 15, 5))
    def test_transformation_range(self, angle, translate, scale, shear, pil_image, input_img):
        self._test_transformation(
            angle=angle,
            translate=(translate, translate),
            scale=scale,
            shear=(shear, shear),
            pil_image=pil_image,
            input_img=input_img,
        )


def test_random_affine():

    with pytest.raises(ValueError):
        transforms.RandomAffine(-0.7)
    with pytest.raises(ValueError):
        transforms.RandomAffine([-0.7])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-0.7, 0, 0.7])
    with pytest.raises(TypeError):
        transforms.RandomAffine([-90, 90], translate=2.0)
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[-1.0, 1.0])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[-1.0, 0.0, 1.0])

    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.0])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[-1.0, 1.0])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, -0.5])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, 3.0, -0.5])

    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, 0.5], shear=-7)
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, 0.5], shear=[-10])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, 0.5], shear=[-10, 0, 10])
    with pytest.raises(ValueError):
        transforms.RandomAffine([-90, 90], translate=[0.2, 0.2], scale=[0.5, 0.5], shear=[-10, 0, 10, 0, 10])

    # assert fill being either a Sequence or a Number
    with pytest.raises(TypeError):
        transforms.RandomAffine(0, fill={})

    t = transforms.RandomAffine(0, fill=None)
    assert t.fill == 0

    x = np.zeros((100, 100, 3), dtype=np.uint8)
    img = F.to_pil_image(x)

    t = transforms.RandomAffine(10, translate=[0.5, 0.3], scale=[0.7, 1.3], shear=[-10, 10, 20, 40])
    for _ in range(100):
        angle, translations, scale, shear = t.get_params(t.degrees, t.translate, t.scale, t.shear, img_size=img.size)
        assert -10 < angle < 10
        assert -img.size[0] * 0.5 <= translations[0] <= img.size[0] * 0.5
        assert -img.size[1] * 0.5 <= translations[1] <= img.size[1] * 0.5
        assert 0.7 < scale < 1.3
        assert -10 < shear[0] < 10
        assert -20 < shear[1] < 40

    # Checking if RandomAffine can be printed as string
    t.__repr__()

    t = transforms.RandomAffine(10, interpolation=transforms.InterpolationMode.BILINEAR)
    assert "bilinear" in t.__repr__()

    t = transforms.RandomAffine(10, interpolation=Image.BILINEAR)
    assert t.interpolation == transforms.InterpolationMode.BILINEAR


def test_elastic_transformation():
    with pytest.raises(TypeError, match=r"alpha should be float or a sequence of floats"):
        transforms.ElasticTransform(alpha=True, sigma=2.0)
    with pytest.raises(TypeError, match=r"alpha should be a sequence of floats"):
        transforms.ElasticTransform(alpha=[1.0, True], sigma=2.0)
    with pytest.raises(ValueError, match=r"alpha is a sequence its length should be 2"):
        transforms.ElasticTransform(alpha=[1.0, 0.0, 1.0], sigma=2.0)

    with pytest.raises(TypeError, match=r"sigma should be float or a sequence of floats"):
        transforms.ElasticTransform(alpha=2.0, sigma=True)
    with pytest.raises(TypeError, match=r"sigma should be a sequence of floats"):
        transforms.ElasticTransform(alpha=2.0, sigma=[1.0, True])
    with pytest.raises(ValueError, match=r"sigma is a sequence its length should be 2"):
        transforms.ElasticTransform(alpha=2.0, sigma=[1.0, 0.0, 1.0])

    t = transforms.transforms.ElasticTransform(alpha=2.0, sigma=2.0, interpolation=Image.BILINEAR)
    assert t.interpolation == transforms.InterpolationMode.BILINEAR

    with pytest.raises(TypeError, match=r"fill should be int or float"):
        transforms.ElasticTransform(alpha=1.0, sigma=1.0, fill={})

    x = torch.randint(0, 256, (3, 32, 32), dtype=torch.uint8)
    img = F.to_pil_image(x)
    t = transforms.ElasticTransform(alpha=0.0, sigma=0.0)
    transformed_img = t(img)
    assert transformed_img == img

    # Smoke test on PIL images
    t = transforms.ElasticTransform(alpha=0.5, sigma=0.23)
    transformed_img = t(img)
    assert isinstance(transformed_img, Image.Image)

    # Checking if ElasticTransform can be printed as string
    t.__repr__()


def test_random_grayscale_with_grayscale_input():
    transform = transforms.RandomGrayscale(p=1.0)

    image_tensor = torch.randint(0, 256, (1, 16, 16), dtype=torch.uint8)
    output_tensor = transform(image_tensor)
    torch.testing.assert_close(output_tensor, image_tensor)

    image_pil = F.to_pil_image(image_tensor)
    output_pil = transform(image_pil)
    torch.testing.assert_close(F.pil_to_tensor(output_pil), image_tensor)


# TODO: remove in 0.17 when we can delete functional_pil.py and functional_tensor.py
@pytest.mark.parametrize(
    "import_statement",
    (
        "from torchvision.transforms import functional_pil",
        "from torchvision.transforms import functional_tensor",
        "from torchvision.transforms.functional_tensor import resize",
        "from torchvision.transforms.functional_pil import resize",
    ),
)
@pytest.mark.parametrize("from_private", (True, False))
@pytest.mark.skipif(
    sys.platform in ("win32", "cygwin"),
    reason="assert_run_python_script is broken on Windows. Possible fix in https://github.com/pytorch/vision/pull/7346",
)
def test_functional_deprecation_warning(import_statement, from_private):
    if from_private:
        import_statement = import_statement.replace("functional", "_functional")
        source = f"""
        import warnings

        with warnings.catch_warnings():
            warnings.simplefilter("error")
            {import_statement}
        """
    else:
        source = f"""
        import pytest
        with pytest.warns(UserWarning, match="removed in 0.17"):
            {import_statement}
        """
    assert_run_python_script(textwrap.dedent(source))


if __name__ == "__main__":
    pytest.main([__file__])