kornia--kornia/tests/morphology/test_dilation.py

# LICENSE HEADER MANAGED BY add-license-header
#
# Copyright 2018 Kornia Team
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import pytest
import torch

from kornia.morphology import dilation

from testing.base import BaseTester, assert_close
from testing.parametrized_tester import parametrized_test


@parametrized_test(
    smoke_inputs=lambda device, dtype: (
        torch.rand(1, 3, 4, 4, device=device, dtype=dtype),
        torch.ones((3, 3), device=device, dtype=dtype),
    ),
    cardinality_tests=[
        {
            "inputs": lambda device, dtype: (
                torch.ones((1, 3, 4, 4), device=device, dtype=dtype),
                torch.ones((3, 3), device=device, dtype=dtype),
            ),
            "expected_shape": torch.Size([1, 3, 4, 4]),
        },
        {
            "inputs": lambda device, dtype: (
                torch.ones((2, 3, 2, 4), device=device, dtype=dtype),
                torch.ones((3, 3), device=device, dtype=dtype),
            ),
            "expected_shape": torch.Size([2, 3, 2, 4]),
        },
        {
            "inputs": lambda device, dtype: (
                torch.ones((3, 3, 4, 1), device=device, dtype=dtype),
                torch.ones((3, 3), device=device, dtype=dtype),
            ),
            "expected_shape": torch.Size([3, 3, 4, 1]),
        },
        {
            "inputs": lambda device, dtype: (
                torch.ones((3, 2, 5, 5), device=device, dtype=dtype),
                torch.ones((3, 3), device=device, dtype=dtype),
            ),
            "expected_shape": torch.Size([3, 2, 5, 5]),
        },
    ],
    gradcheck_inputs=lambda device: (
        torch.rand(2, 3, 4, 4, requires_grad=True, device=device, dtype=torch.float64),
        torch.rand(3, 3, requires_grad=True, device=device, dtype=torch.float64),
    ),
)
class TestDilate(BaseTester):
    def setup_method(self) -> None:
        self.func = dilation

    def test_kernel(self, device, dtype):
        tensor = torch.tensor([[0.5, 1.0, 0.3], [0.7, 0.3, 0.8], [0.4, 0.9, 0.2]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        kernel = torch.tensor([[0.0, 1.0, 0.0], [1.0, 1.0, 1.0], [0.0, 1.0, 0.0]], device=device, dtype=dtype)
        expected = torch.tensor([[1.0, 1.0, 1.0], [0.7, 1.0, 0.8], [0.9, 0.9, 0.9]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        assert_close(dilation(tensor, kernel, engine="unfold"), expected, atol=1e-4, rtol=1e-4)
        assert_close(dilation(tensor, kernel, engine="convolution"), expected, atol=1e-3, rtol=1e-3)

    def test_structural_element(self, device, dtype):
        tensor = torch.tensor([[0.5, 1.0, 0.3], [0.7, 0.3, 0.8], [0.4, 0.9, 0.2]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        structural_element = torch.tensor(
            [[-1.0, 0.0, -1.0], [0.0, 0.0, 0.0], [-1.0, 0.0, -1.0]], device=device, dtype=dtype
        )
        expected = torch.tensor([[1.0, 1.0, 1.0], [0.7, 1.0, 0.8], [0.9, 0.9, 0.9]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        assert_close(
            dilation(
                tensor, torch.ones_like(structural_element), structuring_element=structural_element, engine="unfold"
            ),
            expected,
            atol=1e-3,
            rtol=1e-3,
        )
        assert_close(
            dilation(
                tensor,
                torch.ones_like(structural_element),
                structuring_element=structural_element,
                engine="convolution",
            ),
            expected,
            atol=1e-3,
            rtol=1e-3,
        )

    def test_flip(self, device, dtype):
        tensor = torch.tensor([[0.5, 1.0, 0.3], [0.7, 0.3, 0.8], [0.4, 0.9, 0.2]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        kernel = torch.tensor([[0.0, 1.0, 1.0], [0.0, 1.0, 1.0], [0.0, 1.0, 1.0]], device=device, dtype=dtype)
        expected = torch.tensor([[0.7, 1.0, 1.0], [0.7, 1.0, 1.0], [0.7, 0.9, 0.9]], device=device, dtype=dtype)[
            None, None, :, :
        ]
        assert_close(dilation(tensor, kernel), expected, atol=1e-3, rtol=1e-3)

    def test_exception(self, device, dtype):
        tensor = torch.ones(1, 1, 3, 4, device=device, dtype=dtype)
        kernel = torch.ones(3, 3, device=device, dtype=dtype)

        with pytest.raises(TypeError):
            assert dilation([0.0], kernel)

        with pytest.raises(TypeError):
            assert dilation(tensor, [0.0])

        with pytest.raises(ValueError):
            test = torch.ones(2, 3, 4, device=device, dtype=dtype)
            assert dilation(test, kernel)

        with pytest.raises(ValueError):
            test = torch.ones(2, 3, 4, device=device, dtype=dtype)
            assert dilation(tensor, test)

        with pytest.raises(NotImplementedError, match="unknown"):
            dilation(tensor, kernel, engine="invalid_engine")

    def test_custom_origin(self, device, dtype):
        # Custom origin shifts the structuring element anchor point
        tensor = torch.zeros(1, 1, 5, 5, device=device, dtype=dtype)
        tensor[0, 0, 2, 2] = 1.0  # single hot pixel in center
        kernel = torch.ones(3, 3, device=device, dtype=dtype)

        # Default origin (center): dilation spreads symmetrically
        out_default = dilation(tensor, kernel)
        # Custom origin (top-left corner): effect shifts
        out_custom = dilation(tensor, kernel, origin=[0, 0])
        # Results should differ when the anchor point changes
        assert not torch.equal(out_default, out_custom)

    @pytest.mark.jit()
    def test_jit(self, device, dtype):
        op = dilation
        op_script = torch.jit.script(op)

        tensor = torch.rand(1, 2, 7, 7, device=device, dtype=dtype)
        kernel = torch.ones(3, 3, device=device, dtype=dtype)

        actual = op_script(tensor, kernel)
        expected = op(tensor, kernel)

        assert_close(actual, expected)