diff --git a/docs/source/utils.rst b/docs/source/utils.rst index 527247799f..fef671e1f8 100644 --- a/docs/source/utils.rst +++ b/docs/source/utils.rst @@ -81,3 +81,8 @@ Component store --------------- .. autoclass:: monai.utils.component_store.ComponentStore :members: + +Ordering +-------- +.. automodule:: monai.utils.ordering + :members: diff --git a/monai/utils/ordering.py b/monai/utils/ordering.py new file mode 100644 index 0000000000..1be61f98ab --- /dev/null +++ b/monai/utils/ordering.py @@ -0,0 +1,207 @@ +# Copyright (c) MONAI Consortium +# 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. + +from __future__ import annotations + +import numpy as np + +from monai.utils.enums import OrderingTransformations, OrderingType + + +class Ordering: + """ + Ordering class that projects a 2D or 3D image into a 1D sequence. It also allows the image to be transformed with + one of the following transformations: + Reflection (see np.flip for more details). + Transposition (see np.transpose for more details). + 90-degree rotation (see np.rot90 for more details). + + The transformations are applied in the order specified by the transformation_order parameter. + + Args: + ordering_type: The ordering type. One of the following: + - 'raster_scan': The image is projected into a 1D sequence by scanning the image from left to right and from + top to bottom. Also called a row major ordering. + - 's_curve': The image is projected into a 1D sequence by scanning the image in a circular snake like + pattern from top left towards right gowing in a spiral towards the center. + - random': The image is projected into a 1D sequence by randomly shuffling the image. + spatial_dims: The number of spatial dimensions of the image. + dimensions: The dimensions of the image. + reflected_spatial_dims: A tuple of booleans indicating whether to reflect the image along each spatial dimension. + transpositions_axes: A tuple of tuples indicating the axes to transpose the image along. + rot90_axes: A tuple of tuples indicating the axes to rotate the image along. + transformation_order: The order in which to apply the transformations. + """ + + def __init__( + self, + ordering_type: str, + spatial_dims: int, + dimensions: tuple[int, int, int] | tuple[int, int, int, int], + reflected_spatial_dims: tuple[bool, bool] | None = None, + transpositions_axes: tuple[tuple[int, int], ...] | tuple[tuple[int, int, int], ...] | None = None, + rot90_axes: tuple[tuple[int, int], ...] | None = None, + transformation_order: tuple[str, ...] = ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + ) -> None: + super().__init__() + self.ordering_type = ordering_type + + if self.ordering_type not in list(OrderingType): + raise ValueError( + f"ordering_type must be one of the following {list(OrderingType)}, but got {self.ordering_type}." + ) + + self.spatial_dims = spatial_dims + self.dimensions = dimensions + + if len(dimensions) != self.spatial_dims + 1: + raise ValueError(f"dimensions must be of length {self.spatial_dims + 1}, but got {len(dimensions)}.") + + self.reflected_spatial_dims = reflected_spatial_dims + self.transpositions_axes = transpositions_axes + self.rot90_axes = rot90_axes + if len(set(transformation_order)) != len(transformation_order): + raise ValueError(f"No duplicates are allowed. Received {transformation_order}.") + + for transformation in transformation_order: + if transformation not in list(OrderingTransformations): + raise ValueError( + f"Valid transformations are {list(OrderingTransformations)} but received {transformation}." + ) + self.transformation_order = transformation_order + + self.template = self._create_template() + self._sequence_ordering = self._create_ordering() + self._revert_sequence_ordering = np.argsort(self._sequence_ordering) + + def __call__(self, x: np.ndarray) -> np.ndarray: + x = x[self._sequence_ordering] + + return x + + def get_sequence_ordering(self) -> np.ndarray: + return self._sequence_ordering + + def get_revert_sequence_ordering(self) -> np.ndarray: + return self._revert_sequence_ordering + + def _create_ordering(self) -> np.ndarray: + self.template = self._transform_template() + order = self._order_template(template=self.template) + + return order + + def _create_template(self) -> np.ndarray: + spatial_dimensions = self.dimensions[1:] + template = np.arange(np.prod(spatial_dimensions)).reshape(*spatial_dimensions) + + return template + + def _transform_template(self) -> np.ndarray: + for transformation in self.transformation_order: + if transformation == OrderingTransformations.TRANSPOSE.value: + self.template = self._transpose_template(template=self.template) + elif transformation == OrderingTransformations.ROTATE_90.value: + self.template = self._rot90_template(template=self.template) + elif transformation == OrderingTransformations.REFLECT.value: + self.template = self._flip_template(template=self.template) + + return self.template + + def _transpose_template(self, template: np.ndarray) -> np.ndarray: + if self.transpositions_axes is not None: + for axes in self.transpositions_axes: + template = np.transpose(template, axes=axes) + + return template + + def _flip_template(self, template: np.ndarray) -> np.ndarray: + if self.reflected_spatial_dims is not None: + for axis, to_reflect in enumerate(self.reflected_spatial_dims): + template = np.flip(template, axis=axis) if to_reflect else template + + return template + + def _rot90_template(self, template: np.ndarray) -> np.ndarray: + if self.rot90_axes is not None: + for axes in self.rot90_axes: + template = np.rot90(template, axes=axes) + + return template + + def _order_template(self, template: np.ndarray) -> np.ndarray: + depths = None + if self.spatial_dims == 2: + rows, columns = template.shape[0], template.shape[1] + else: + rows, columns, depths = (template.shape[0], template.shape[1], template.shape[2]) + + sequence = eval(f"self.{self.ordering_type}_idx")(rows, columns, depths) + + ordering = np.array([template[tuple(e)] for e in sequence]) + + return ordering + + @staticmethod + def raster_scan_idx(rows: int, cols: int, depths: int | None = None) -> np.ndarray: + idx: list[tuple] = [] + + for r in range(rows): + for c in range(cols): + if depths is not None: + for d in range(depths): + idx.append((r, c, d)) + else: + idx.append((r, c)) + + idx_np = np.array(idx) + + return idx_np + + @staticmethod + def s_curve_idx(rows: int, cols: int, depths: int | None = None) -> np.ndarray: + idx: list[tuple] = [] + + for r in range(rows): + col_idx = range(cols) if r % 2 == 0 else range(cols - 1, -1, -1) + for c in col_idx: + if depths: + depth_idx = range(depths) if c % 2 == 0 else range(depths - 1, -1, -1) + + for d in depth_idx: + idx.append((r, c, d)) + else: + idx.append((r, c)) + + idx_np = np.array(idx) + + return idx_np + + @staticmethod + def random_idx(rows: int, cols: int, depths: int | None = None) -> np.ndarray: + idx: list[tuple] = [] + + for r in range(rows): + for c in range(cols): + if depths: + for d in range(depths): + idx.append((r, c, d)) + else: + idx.append((r, c)) + + idx_np = np.array(idx) + np.random.shuffle(idx_np) + + return idx_np diff --git a/tests/test_ordering.py b/tests/test_ordering.py new file mode 100644 index 0000000000..0c52dba5e5 --- /dev/null +++ b/tests/test_ordering.py @@ -0,0 +1,318 @@ +# Copyright (c) MONAI Consortium +# 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. + +from __future__ import annotations + +import unittest + +import numpy as np +from parameterized import parameterized + +from monai.utils.enums import OrderingTransformations, OrderingType +from monai.utils.ordering import Ordering + +TEST_2D_NON_RANDOM = [ + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 1, 2, 3], + ], + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 1, 3, 2], + ], + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [2, 3, 0, 1], + ], + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [2, 3, 1, 0], + ], + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": ((1, 0),), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 2, 1, 3], + ], + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": ((1, 0),), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 2, 3, 1], + ], + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": (), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [1, 3, 0, 2], + ], + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": (), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [1, 3, 2, 0], + ], + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": ((1, 0),), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 1, 2, 3], + ], + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": ((1, 0),), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 1, 3, 2], + ], +] + +TEST_2D_RANDOM = [ + [ + { + "ordering_type": OrderingType.RANDOM, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": ((1, 0),), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [[0, 1, 2, 3], [0, 1, 3, 2]], + ] +] + +TEST_3D = [ + [ + { + "ordering_type": OrderingType.RASTER_SCAN, + "spatial_dims": 3, + "dimensions": (1, 2, 2, 2), + "reflected_spatial_dims": (), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + }, + [0, 1, 2, 3, 4, 5, 6, 7], + ] +] + +TEST_ORDERING_TYPE_FAILURE = [ + [ + { + "ordering_type": "hilbert", + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": ((1, 0),), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + } + ] +] + +TEST_ORDERING_TRANSFORMATION_FAILURE = [ + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": ((1, 0),), + "rot90_axes": ((0, 1),), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + "flip", + ), + } + ] +] + +TEST_REVERT = [ + [ + { + "ordering_type": OrderingType.S_CURVE, + "spatial_dims": 2, + "dimensions": (1, 2, 2), + "reflected_spatial_dims": (True, False), + "transpositions_axes": (), + "rot90_axes": (), + "transformation_order": ( + OrderingTransformations.TRANSPOSE.value, + OrderingTransformations.ROTATE_90.value, + OrderingTransformations.REFLECT.value, + ), + } + ] +] + + +class TestOrdering(unittest.TestCase): + @parameterized.expand(TEST_2D_NON_RANDOM + TEST_3D) + def test_ordering(self, input_param, expected_sequence_ordering): + ordering = Ordering(**input_param) + self.assertTrue(np.array_equal(ordering.get_sequence_ordering(), expected_sequence_ordering, equal_nan=True)) + + @parameterized.expand(TEST_ORDERING_TYPE_FAILURE) + def test_ordering_type_failure(self, input_param): + with self.assertRaises(ValueError): + Ordering(**input_param) + + @parameterized.expand(TEST_ORDERING_TRANSFORMATION_FAILURE) + def test_ordering_transformation_failure(self, input_param): + with self.assertRaises(ValueError): + Ordering(**input_param) + + @parameterized.expand(TEST_2D_RANDOM) + def test_random(self, input_param, not_in_expected_sequence_ordering): + ordering = Ordering(**input_param) + + not_in = [ + np.array_equal(sequence, ordering.get_sequence_ordering(), equal_nan=True) + for sequence in not_in_expected_sequence_ordering + ] + + self.assertFalse(np.any(not_in)) + + @parameterized.expand(TEST_REVERT) + def test_revert(self, input_param): + sequence = np.random.randint(0, 100, size=input_param["dimensions"]).flatten() + + ordering = Ordering(**input_param) + + reverted_sequence = sequence[ordering.get_sequence_ordering()] + reverted_sequence = reverted_sequence[ordering.get_revert_sequence_ordering()] + + self.assertTrue(np.array_equal(sequence, reverted_sequence, equal_nan=True)) + + +if __name__ == "__main__": + unittest.main()