[Feature]: Add Part2 of data transform (#1730)

* [Refactor]: New commit of Part2 of data transform

* [Fix]: Fix lint

* [Fix]: Change flip reisze to prefix

* [Refactor]: Delete redundant code in ToTensor

* [Fix]:optional

* [Fix]: Change the discription of RandomFlip

* [Refactor]: Change flip_with_flip_direction to flip_on_direction

Co-authored-by: Your <you@example.com>

mmcv/transforms/__init__.py

@@ -1,10 +1,22 @@
 # Copyright (c) OpenMMLab. All rights reserved.
 from .builder import TRANSFORMS
 from .loading import LoadAnnotation, LoadImageFromFile
-from .processing import Normalize, Pad, Resize
+from .processing import Normalize, Pad, RandomFlip, RandomResize, Resize
 from .wrappers import ApplyToMultiple, Compose, RandomChoice, Remap
 
-__all__ = [
+try:
-    'TRANSFORMS', 'ApplyToMultiple', 'Compose', 'RandomChoice', 'Remap',
+    import torch  # noqa: F401
-    'LoadImageFromFile', 'LoadAnnotation', 'Normalize', 'Resize', 'Pad'
+except ImportError:
-]
+    __all__ = [
+        'TRANSFORMS', 'ApplyToMultiple', 'Compose', 'RandomChoice', 'Remap',
+        'LoadImageFromFile', 'LoadAnnotation', 'Normalize', 'Resize', 'Pad',
+        'RandomFlip', 'RandomResize'
+    ]
+else:
+    from .formatting import ImageToTensor, ToTensor, to_tensor
+
+    __all__ = [
+        'TRANSFORMS', 'ApplyToMultiple', 'Compose', 'RandomChoice', 'Remap',
+        'LoadImageFromFile', 'LoadAnnotation', 'Normalize', 'Resize', 'Pad',
+        'ToTensor', 'to_tensor', 'ImageToTensor', 'RandomFlip', 'RandomResize'
+    ]

mmcv/transforms/formatting.py

@@ -0,0 +1,125 @@
+# Copyright (c) OpenMMLab. All rights reserved.
+from typing import Sequence, Union
+
+import numpy as np
+import torch
+
+import mmcv
+from .base import BaseTransform
+from .builder import TRANSFORMS
+
+
+def to_tensor(
+    data: Union[torch.Tensor, np.ndarray, Sequence, int,
+                float]) -> torch.Tensor:
+    """Convert objects of various python types to :obj:`torch.Tensor`.
+
+    Supported types are: :class:`numpy.ndarray`, :class:`torch.Tensor`,
+    :class:`Sequence`, :class:`int` and :class:`float`.
+    Args:
+        data (torch.Tensor | numpy.ndarray | Sequence | int | float): Data to
+            be converted.
+    Returns:
+        torch.Tensor: the converted data.
+    """
+
+    if isinstance(data, torch.Tensor):
+        return data
+    elif isinstance(data, np.ndarray):
+        return torch.from_numpy(data)
+    elif isinstance(data, Sequence) and not mmcv.is_str(data):
+        return torch.tensor(data)
+    elif isinstance(data, int):
+        return torch.LongTensor([data])
+    elif isinstance(data, float):
+        return torch.FloatTensor([data])
+    else:
+        raise TypeError(f'type {type(data)} cannot be converted to tensor.')
+
+
+@TRANSFORMS.register_module()
+class ToTensor(BaseTransform):
+    """Convert some results to :obj:`torch.Tensor` by given keys.
+
+    Required keys:
+
+    - all these keys in `keys`
+
+    Modified Keys:
+
+    - all these keys in `keys`
+
+    Args:
+        keys (Sequence[str]): Keys that need to be converted to Tensor.
+    """
+
+    def __init__(self, keys: Sequence[str]) -> None:
+        self.keys = keys
+
+    def transform(self, results: dict) -> dict:
+        """Transform function to convert data to `torch.Tensor`.
+
+        Args:
+            results (dict): Result dict from loading pipeline.
+        Returns:
+            dict: `keys` in results will be updated.
+        """
+        for key in self.keys:
+
+            key_list = key.split('.')
+            cur_item = results
+            for i in range(len(key_list)):
+                if key_list[i] not in cur_item:
+                    raise KeyError(f'Can not find key {key}')
+                if i == len(key_list) - 1:
+                    cur_item[key_list[i]] = to_tensor(cur_item[key_list[i]])
+                    break
+                cur_item = cur_item[key_list[i]]
+
+        return results
+
+    def __repr__(self) -> str:
+        return self.__class__.__name__ + f'(keys={self.keys})'
+
+
+@TRANSFORMS.register_module()
+class ImageToTensor(BaseTransform):
+    """Convert image to :obj:`torch.Tensor` by given keys.
+
+    The dimension order of input image is (H, W, C). The pipeline will convert
+    it to (C, H, W). If only 2 dimension (H, W) is given, the output would be
+    (1, H, W).
+
+    Required keys:
+
+    - all these keys in `keys`
+
+    Modified Keys:
+
+    - all these keys in `keys`
+
+    Args:
+        keys (Sequence[str]): Key of images to be converted to Tensor.
+    """
+
+    def __init__(self, keys: dict) -> None:
+        self.keys = keys
+
+    def transform(self, results: dict) -> dict:
+        """Transform function to convert image in results to
+        :obj:`torch.Tensor` and transpose the channel order.
+        Args:
+            results (dict): Result dict contains the image data to convert.
+        Returns:
+            dict: The result dict contains the image converted
+            to :obj:``torch.Tensor`` and transposed to (C, H, W) order.
+        """
+        for key in self.keys:
+            img = results[key]
+            if len(img.shape) < 3:
+                img = np.expand_dims(img, -1)
+            results[key] = (to_tensor(img.transpose(2, 0, 1))).contiguous()
+        return results
+
+    def __repr__(self) -> str:
+        return self.__class__.__name__ + f'(keys={self.keys})'

mmcv/transforms/processing.py

@@ -1,5 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
-from typing import Optional, Sequence, Tuple, Union
+from typing import Iterable, List, Optional, Sequence, Tuple, Union
 
 import numpy as np
 
@@ -400,3 +400,408 @@ class Pad(BaseTransform):
         repr_str += f'pad_val={self.pad_val}), '
         repr_str += f'padding_mode={self.padding_mode})'
         return repr_str
+
+
+@TRANSFORMS.register_module()
+class RandomFlip(BaseTransform):
+    """Flip the image & bbox & keypoints & segmentation map.
+
+    There are 3 flip modes:
+
+    - ``prob`` is float, ``direction`` is string
+
+        the image will be flipped on the given direction with probability
+        of ``prob`` . E.g., ``prob=0.5``, ``direction='horizontal'``,
+        then image will be horizontally flipped with probability of 0.5.
+
+    - ``prob`` is float, ``direction`` is list of string
+
+        the image will be flipped on the given direction with probability of
+        ``prob/len(direction)``. E.g., ``prob=0.5``,
+        ``direction=['horizontal', 'vertical']``, then image will be
+        horizontally flipped with probability of 0.25, vertically with
+        probability of 0.25.
+
+    - ``prob`` is list of float, ``direction`` is list of string
+
+        given ``len(prob) == len(direction)``, the image will
+        be ``direction[i]`` ly flipped with probability of ``prob[i]``.
+        E.g., ``prob=[0.3, 0.5]``, ``direction=['horizontal',
+        'vertical']``, then image will be horizontally flipped with
+        probability of 0.3, vertically with probability of 0.5.
+
+    Required Keys:
+
+    - img
+    - gt_bboxes
+    - gt_semantic_seg
+    - gt_keypoints
+
+    Modified Keys:
+
+    - img
+    - gt_bboxes
+    - gt_semantic_seg
+    - gt_keypoints
+
+    Added Keys:
+
+    - flip
+    - flip_direction
+
+    Args:
+         prob (float | list[float], optional): The flipping probability.
+             Defaults to None.
+         direction(str | list[str]): The flipping direction. Options
+             If input is a list, the length must equal ``prob``. Each
+             element in ``prob`` indicates the flip probability of
+             corresponding direction. Defaults to horizontal.
+    """
+
+    def __init__(
+            self,
+            prob: Optional[Union[float, Iterable[float]]] = None,
+            direction: Union[str,
+                             Sequence[Optional[str]]] = 'horizontal') -> None:
+        if isinstance(prob, list):
+            assert mmcv.is_list_of(prob, float)
+            assert 0 <= sum(prob) <= 1
+        elif isinstance(prob, float):
+            assert 0 <= prob <= 1
+        else:
+            raise ValueError(f"probs must be float or list of float, but \
+                              got '{type(prob)}'.")
+        self.prob = prob
+
+        valid_directions = ['horizontal', 'vertical', 'diagonal']
+        if isinstance(direction, str):
+            assert direction in valid_directions
+        elif isinstance(direction, list):
+            assert mmcv.is_list_of(direction, str)
+            assert set(direction).issubset(set(valid_directions))
+        else:
+            raise ValueError(f"direction must be either str or list of str, \
+                               but got '{type(direction)}'.")
+        self.direction = direction
+
+        if isinstance(prob, list):
+            assert len(prob) == len(self.direction)
+
+    def flip_bbox(self, bboxes: np.ndarray, img_shape: Tuple[int, int],
+                  direction: str) -> np.ndarray:
+        """Flip bboxes horizontally.
+
+        Args:
+            bboxes (numpy.ndarray): Bounding boxes, shape (..., 4*k)
+            img_shape (tuple[int]): Image shape (height, width)
+            direction (str): Flip direction. Options are 'horizontal',
+                'vertical'.
+        Returns:
+            numpy.ndarray: Flipped bounding boxes.
+        """
+        assert bboxes.shape[-1] % 4 == 0
+        flipped = bboxes.copy()
+        h, w = img_shape
+        if direction == 'horizontal':
+            flipped[..., 0::4] = w - bboxes[..., 2::4]
+            flipped[..., 2::4] = w - bboxes[..., 0::4]
+        elif direction == 'vertical':
+            flipped[..., 1::4] = h - bboxes[..., 3::4]
+            flipped[..., 3::4] = h - bboxes[..., 1::4]
+        elif direction == 'diagonal':
+            flipped[..., 0::4] = w - bboxes[..., 2::4]
+            flipped[..., 1::4] = h - bboxes[..., 3::4]
+            flipped[..., 2::4] = w - bboxes[..., 0::4]
+            flipped[..., 3::4] = h - bboxes[..., 1::4]
+        else:
+            raise ValueError(
+                f"Flipping direction must be 'horizontal', 'vertical', \
+                  or 'diagnal', but got '{direction}'")
+        return flipped
+
+    def flip_keypoints(self, keypoints: np.ndarray, img_shape: Tuple[int, int],
+                       direction: str) -> np.ndarray:
+        """Flip keypoints horizontally, vertically or diagnally.
+
+        Args:
+            keypoints (numpy.ndarray): Keypoints, shape (..., 2)
+            img_shape (tuple[int]): Image shape (height, width)
+            direction (str): Flip direction. Options are 'horizontal',
+                'vertical'.
+        Returns:
+            numpy.ndarray: Flipped keypoints.
+        """
+
+        meta_info = keypoints[..., 2:]
+        keypoints = keypoints[..., :2]
+        flipped = keypoints.copy()
+        h, w = img_shape
+        if direction == 'horizontal':
+            flipped[..., 0::2] = w - keypoints[..., 0::2]
+        elif direction == 'vertical':
+            flipped[..., 1::2] = h - keypoints[..., 1::2]
+        elif direction == 'diagonal':
+            flipped[..., 0::2] = w - keypoints[..., 0::2]
+            flipped[..., 1::2] = h - keypoints[..., 1::2]
+        else:
+            raise ValueError(
+                f"Flipping direction must be 'horizontal', 'vertical', \
+                  or 'diagnal', but got '{direction}'")
+        flipped = np.concatenate([keypoints, meta_info], axis=-1)
+        return flipped
+
+    def _choose_direction(self) -> str:
+        """Choose the flip direction according to `prob` and `direction`"""
+        if isinstance(self.direction,
+                      Sequence) and not isinstance(self.direction, str):
+            # None means non-flip
+            direction_list: list = list(self.direction) + [None]
+        elif isinstance(self.direction, str):
+            # None means non-flip
+            direction_list = [self.direction, None]
+
+        if isinstance(self.prob, list):
+            non_prob: float = 1 - sum(self.prob)
+            prob_list = self.prob + [non_prob]
+        elif isinstance(self.prob, float):
+            non_prob = 1. - self.prob
+            # exclude non-flip
+            single_ratio = self.prob / (len(direction_list) - 1)
+            prob_list = [single_ratio] * (len(direction_list) - 1) + [non_prob]
+
+        cur_dir = np.random.choice(direction_list, p=prob_list)
+
+        return cur_dir
+
+    def _flip(self, results: dict) -> None:
+        """Flip images, bounding boxes, semantic segmentation map and
+        keypoints."""
+        # flip image
+        results['img'] = mmcv.imflip(
+            results['img'], direction=results['flip_direction'])
+
+        img_shape = results['img'].shape[:2]
+
+        # flip bboxes
+        if results.get('gt_bboxes', None) is not None:
+            results['gt_bboxes'] = self.flip_bbox(results['gt_bboxes'],
+                                                  img_shape,
+                                                  results['flip_direction'])
+
+        # flip keypoints
+        if results.get('gt_keypoints', None) is not None:
+            results['gt_keypoints'] = self.flip_keypoints(
+                results['gt_keypoints'], img_shape, results['flip_direction'])
+
+        # flip segs
+        if results.get('gt_semantic_seg', None) is not None:
+            results['gt_semantic_seg'] = mmcv.imflip(
+                results['gt_semantic_seg'],
+                direction=results['flip_direction'])
+
+    def _flip_on_direction(self, results: dict) -> None:
+        """Function to flip images, bounding boxes, semantic segmentation map
+        and keypoints."""
+        cur_dir = self._choose_direction()
+        if cur_dir is None:
+            results['flip'] = False
+            results['flip_direction'] = None
+        else:
+            results['flip'] = True
+            results['flip_direction'] = cur_dir
+            self._flip(results)
+
+    def transform(self, results: dict) -> dict:
+        """Transform function to flip images, bounding boxes, semantic
+        segmentation map and keypoints.
+
+        Args:
+            results (dict): Result dict from loading pipeline.
+        Returns:
+            dict: Flipped results, 'img', 'gt_bboxes', 'gt_semantic_seg',
+            'gt_keypoints', 'flip', and 'flip_direction' keys are
+            updated in result dict.
+        """
+        self._flip_on_direction(results)
+
+        return results
+
+    def __repr__(self) -> str:
+        repr_str = self.__class__.__name__
+        repr_str += f'(scale={self.prob}, '
+        repr_str += f'interpolation={self.direction})'
+
+        return repr_str
+
+
+@TRANSFORMS.register_module()
+class RandomResize(BaseTransform):
+    """Random resize images & bbox & keypoints.
+
+    Added or updated keys: scale, scale_factor, keep_ratio, img, height, width,
+    gt_bboxes, gt_semantic_seg, and gt_keypoints.
+    How to choose the target scale to resize the image will follow the rules
+    below:
+
+    - if `scale` is a list of tuple, the first value of the target scale is
+      sampled from [`scale[0][0]`, `scale[1][0]`] uniformally and the second
+      value of the target scale is sampled from [`scale[0][1]`, `scale[1][1]`]
+      uniformally.
+    - if `scale` is a tuple, the first and second values of the target scale
+      is equal to the first and second values of `scale` multiplied by a value
+      sampled from [`ratio_range[0]`, `ratio_range[1]`] uniformally.
+
+    Required Keys:
+
+    - img
+    - gt_bboxes
+    - gt_semantic_seg
+    - gt_keypoints
+
+    Modified Keys:
+
+    - img
+    - gt_bboxes
+    - gt_semantic_seg
+    - gt_keypoints
+
+    Added Keys:
+
+    - scale
+    - scale_factor
+    - keep_ratio
+
+    Args:
+        scale (tuple or list[tuple], optional): Images scales for resizing.
+            Defaults to None.
+        ratio_range (tuple[float], optional): (min_ratio, max_ratio).
+            Defaults to None.
+        keep_ratio (bool): Whether to keep the aspect ratio when resizing the
+            image. Defaults to True.
+        clip_object_border (bool): Whether to clip the objects
+            outside the border of the image. In some dataset like MOT17, the
+            gt bboxes are allowed to cross the border of images. Therefore,
+            we don't need to clip the gt bboxes in these cases.
+            Defaults to True.
+        backend (str): Image resize backend, choices are 'cv2' and 'pillow'.
+            These two backends generates slightly different results. Defaults
+            to 'cv2'.
+        interpolation (str): How to interpolate the original image when
+            resizing. Defaults to 'bilinear'.
+    """
+
+    def __init__(self,
+                 scale: Union[Tuple[int, int], List[Tuple[int, int]]] = None,
+                 ratio_range: Tuple[float, float] = None,
+                 keep_ratio: bool = True,
+                 clip_object_border: bool = True,
+                 backend: str = 'cv2',
+                 interpolation: str = 'bilinear') -> None:
+
+        assert scale is not None
+
+        self.scale = scale
+        self.ratio_range = ratio_range
+        self.keep_ratio = keep_ratio
+        self.clip_object_border = clip_object_border
+        self.backend = backend
+        self.interpolation = interpolation
+
+        # create a empty Reisize object
+        self.resize = Resize(0)
+        self.resize.keep_ratio = keep_ratio
+        self.resize.clip_object_border = clip_object_border
+        self.resize.backend = backend
+        self.resize.interpolation = interpolation
+
+    @staticmethod
+    def _random_sample(scales: Sequence[Tuple[int, int]]) -> Tuple[int, int]:
+        """Private function to randomly sample a scale from a list of tuples.
+
+        Args:
+            scales (list[tuple]): Images scale range for sampling.
+                There must be two tuples in scales, which specify the lower
+                and upper bound of image scales.
+        Returns:
+            tuple: Returns the target scale.
+        """
+
+        assert mmcv.is_list_of(scales, tuple) and len(scales) == 2
+        scale_long = [max(s) for s in scales]
+        scale_short = [min(s) for s in scales]
+        long_edge = np.random.randint(min(scale_long), max(scale_long) + 1)
+        short_edge = np.random.randint(min(scale_short), max(scale_short) + 1)
+        scale = (long_edge, short_edge)
+        return scale
+
+    @staticmethod
+    def _random_sample_ratio(
+            scale: tuple, ratio_range: Tuple[float, float]) -> Tuple[int, int]:
+        """Private function to randomly sample a scale from a tuple.
+
+        A ratio will be randomly sampled from the range specified by
+        ``ratio_range``. Then it would be multiplied with ``scale`` to
+        generate sampled scale.
+        Args:
+            scale (tuple): Images scale base to multiply with ratio.
+            ratio_range (tuple[float]): The minimum and maximum ratio to scale
+                the ``scale``.
+        Returns:
+            tuple: Returns the target scale.
+        """
+
+        assert isinstance(scale, tuple) and len(scale) == 2
+        min_ratio, max_ratio = ratio_range
+        assert min_ratio <= max_ratio
+        ratio = np.random.random_sample() * (max_ratio - min_ratio) + min_ratio
+        scale = int(scale[0] * ratio), int(scale[1] * ratio)
+        return scale
+
+    def _random_scale(self, results: dict) -> None:
+        """Private function to randomly sample an scale according to the type
+        of `scale`.
+
+        Args:
+            results (dict): Result dict from :obj:`dataset`.
+        Returns:
+            dict: One new key 'scale`is added into ``results``,
+            which would be used by subsequent pipelines.
+        """
+
+        if isinstance(self.scale, tuple):
+            assert self.ratio_range is not None and len(self.ratio_range) == 2
+            scale: Tuple[int, int] = self._random_sample_ratio(
+                self.scale, self.ratio_range)
+        elif mmcv.is_list_of(self.scale, tuple):
+            scale = self._random_sample(self.scale)
+        else:
+            raise NotImplementedError(f"Do not support sampling function \
+                                        for '{self.scale}'")
+
+        results['scale'] = scale
+
+    def transform(self, results: dict) -> dict:
+        """Transform function to resize images, bounding boxes, semantic
+        segmentation map.
+
+        Args:
+            results (dict): Result dict from loading pipeline.
+        Returns:
+            dict: Resized results, 'img', 'gt_bboxes', 'gt_semantic_seg',
+            'gt_keypoints', 'scale', 'scale_factor', 'height', 'width',
+            and 'keep_ratio' keys are updated in result dict.
+        """
+        self._random_scale(results)
+        self.resize.scale = results['scale']
+        results = self.resize.transform(results)
+        return results
+
+    def __repr__(self) -> str:
+        repr_str = self.__class__.__name__
+        repr_str += f'(scale={self.scale}, '
+        repr_str += f'ratio_range={self.ratio_range}, '
+        repr_str += f'keep_ratio={self.keep_ratio}, '
+        repr_str += f'bbox_clip_border={self.clip_object_border}, '
+        repr_str += f'backend={self.backend}, '
+        repr_str += f'interpolation={self.interpolation})'
+        return repr_str

tests/test_transforms/test_transforms_formatting.py

@@ -0,0 +1,101 @@
+# Copyright (c) OpenMMLab. All rights reserved.
+try:
+    import torch
+except ModuleNotFoundError:
+    torch = None
+else:
+    from mmcv.transforms import ToTensor, to_tensor, ImageToTensor
+
+import copy
+
+import numpy as np
+import pytest
+
+
+@pytest.mark.skipif(condition=torch is None, reason='No torch in current env')
+def test_to_tensor():
+
+    # The type of the input object is torch.Tensor
+    data_tensor = torch.tensor([1, 2, 3])
+    tensor_from_tensor = to_tensor(data_tensor)
+    assert isinstance(tensor_from_tensor, torch.Tensor)
+
+    # The type of the input object is numpy.ndarray
+    data_numpy = np.array([1, 2, 3])
+    tensor_from_numpy = to_tensor(data_numpy)
+    assert isinstance(tensor_from_numpy, torch.Tensor)
+
+    # The type of the input object is list
+    data_list = [1, 2, 3]
+    tensor_from_list = to_tensor(data_list)
+    assert isinstance(tensor_from_list, torch.Tensor)
+
+    # The type of the input object is int
+    data_int = 1
+    tensor_from_int = to_tensor(data_int)
+    assert isinstance(tensor_from_int, torch.Tensor)
+
+    # The type of the input object is float
+    data_float = 1.0
+    tensor_from_float = to_tensor(data_float)
+    assert isinstance(tensor_from_float, torch.Tensor)
+
+    # The type of the input object is invalid
+    with pytest.raises(TypeError):
+        data_str = '123'
+        _ = to_tensor(data_str)
+
+
+@pytest.mark.skipif(condition=torch is None, reason='No torch in current env')
+class TestToTensor:
+
+    def test_init(self):
+        TRANSFORM = ToTensor(keys=['img_label'])
+        assert TRANSFORM.keys == ['img_label']
+
+    def test_transform(self):
+        TRANSFORMS = ToTensor(['instances.bbox', 'img_label'])
+
+        # Test multi-level key and single-level key (multi-level key is
+        # not in results)
+        with pytest.raises(KeyError):
+            results = {'instances': {'label': [1]}, 'img_label': [1]}
+            results_tensor = TRANSFORMS.transform(copy.deepcopy(results))
+            assert isinstance(results_tensor['instances']['label'], list)
+            assert isinstance(results_tensor['img_label'], torch.Tensor)
+
+        # Test multi-level key (multi-level key is in results)
+        results = {'instances': {'bbox': [[0, 0, 10, 10]]}, 'img_label': [1]}
+        results_tensor = TRANSFORMS.transform(copy.deepcopy(results))
+        assert isinstance(results_tensor['instances']['bbox'], torch.Tensor)
+
+    def test_repr(self):
+        TRANSFORMS = ToTensor(['instances.bbox', 'img_label'])
+        TRANSFORMS_str = str(TRANSFORMS)
+        isinstance(TRANSFORMS_str, str)
+
+
+@pytest.mark.skipif(condition=torch is None, reason='No torch in current env')
+class TestImageToTensor:
+
+    def test_init(self):
+        TRANSFORMS = ImageToTensor(['img'])
+        assert TRANSFORMS.keys == ['img']
+
+    def test_transform(self):
+        TRANSFORMS = ImageToTensor(['img'])
+
+        # image only has one channel
+        results = {'img': np.zeros((224, 224))}
+        results = TRANSFORMS.transform(results)
+        assert results['img'].shape == (1, 224, 224)
+
+        # image has three channels
+        results = {'img': np.zeros((224, 224, 3))}
+        results = TRANSFORMS.transform(results)
+        assert results['img'].shape == (3, 224, 224)
+
+    def test_repr(self):
+        TRANSFORMS = ImageToTensor(['img'])
+        TRANSFORMS_str = str(TRANSFORMS)
+        assert isinstance(TRANSFORMS_str, str)

tests/test_transforms/test_transforms_processing.py

@@ -6,7 +6,7 @@ import numpy as np
 import pytest
 
 import mmcv
-from mmcv.transforms import Normalize, Pad, Resize
+from mmcv.transforms import Normalize, Pad, RandomFlip, RandomResize, Resize
 
 
 class TestNormalize:
@@ -183,3 +183,154 @@ class TestPad:
         assert repr(trans) == (
             'Pad(size=None, size_divisor=11, pad_to_square=True, '
             "pad_val={'img': 0, 'seg': 255}), padding_mode=edge)")
+
+
+class TestRandomFlip:
+
+    def test_init(self):
+
+        # prob is float
+        TRANSFORMS = RandomFlip(0.1)
+        assert TRANSFORMS.prob == 0.1
+
+        # prob is None
+        with pytest.raises(ValueError):
+            TRANSFORMS = RandomFlip(None)
+            assert TRANSFORMS.prob is None
+
+        # prob is a list
+        TRANSFORMS = RandomFlip([0.1, 0.2], ['horizontal', 'vertical'])
+        assert len(TRANSFORMS.prob) == 2
+        assert len(TRANSFORMS.direction) == 2
+
+        # direction is an invalid type
+        with pytest.raises(ValueError):
+            TRANSFORMS = RandomFlip(0.1, 1)
+
+        # prob is an invalid type
+        with pytest.raises(ValueError):
+            TRANSFORMS = RandomFlip('0.1')
+
+    def test_transform(self):
+
+        results = {
+            'img': np.random.random((224, 224, 3)),
+            'gt_bboxes': np.array([[0, 1, 100, 101]]),
+            'gt_keypoints': np.array([[[100, 100, 1.0]]]),
+            'gt_semantic_seg': np.random.random((224, 224, 3))
+        }
+
+        # horizontal flip
+        TRANSFORMS = RandomFlip([1.0], ['horizontal'])
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert (results_update['gt_bboxes'] == np.array([[124, 1, 224,
+                                                          101]])).all()
+
+        # diagnal flip
+        TRANSFORMS = RandomFlip([1.0], ['diagonal'])
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert (results_update['gt_bboxes'] == np.array([[124, 123, 224,
+                                                          223]])).all()
+
+        # vertical flip
+        TRANSFORMS = RandomFlip([1.0], ['vertical'])
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert (results_update['gt_bboxes'] == np.array([[0, 123, 100,
+                                                          223]])).all()
+
+        # horizontal flip when direction is None
+        TRANSFORMS = RandomFlip(1.0)
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert (results_update['gt_bboxes'] == np.array([[124, 1, 224,
+                                                          101]])).all()
+
+        TRANSFORMS = RandomFlip(0.0)
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert (results_update['gt_bboxes'] == np.array([[0, 1, 100,
+                                                          101]])).all()
+
+        # flip direction is invalid in bbox flip
+        with pytest.raises(ValueError):
+            TRANSFORMS = RandomFlip(1.0)
+            results_update = TRANSFORMS.flip_bbox(results['gt_bboxes'],
+                                                  (224, 224), 'invalid')
+
+        # flip direction is invalid in keypoints flip
+        with pytest.raises(ValueError):
+            TRANSFORMS = RandomFlip(1.0)
+            results_update = TRANSFORMS.flip_keypoints(results['gt_keypoints'],
+                                                       (224, 224), 'invalid')
+
+    def test_repr(self):
+        TRANSFORMS = RandomFlip(0.1)
+        TRANSFORMS_str = str(TRANSFORMS)
+        assert isinstance(TRANSFORMS_str, str)
+
+
+class TestRandomResize:
+
+    def test_init(self):
+        TRANSFORMS = RandomResize(
+            (224, 224),
+            (1.0, 2.0),
+        )
+        assert TRANSFORMS.scale == (224, 224)
+
+    def test_repr(self):
+        TRANSFORMS = RandomResize(
+            (224, 224),
+            (1.0, 2.0),
+        )
+        TRANSFORMS_str = str(TRANSFORMS)
+        assert isinstance(TRANSFORMS_str, str)
+
+    def test_transform(self):
+
+        # choose target scale from init when override is True
+        results = {}
+        TRANSFORMS = RandomResize((224, 224), (1.0, 2.0))
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert results_update['scale'][0] >= 224 and results_update['scale'][
+            0] <= 448
+        assert results_update['scale'][1] >= 224 and results_update['scale'][
+            1] <= 448
+
+        # keep ratio is True
+        results = {
+            'img': np.random.random((224, 224, 3)),
+            'gt_semantic_seg': np.random.random((224, 224, 3)),
+            'gt_bboxes': np.array([[0, 0, 112, 112]]),
+            'gt_keypoints': np.array([[[112, 112]]])
+        }
+        # import pdb
+        # pdb.set_trace()
+        TRANSFORMS = RandomResize((224, 224), (1.0, 2.0), keep_ratio=True)
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert 224 <= results_update['height']
+        assert 448 >= results_update['height']
+        assert 224 <= results_update['width']
+        assert 448 >= results_update['width']
+        assert results_update['keep_ratio']
+        assert results['gt_bboxes'][0][2] >= 112
+        assert results['gt_bboxes'][0][2] <= 112
+
+        # keep ratio is False
+        TRANSFORMS = RandomResize((224, 224), (1.0, 2.0), keep_ratio=False)
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+
+        # choose target scale from init when override is False and scale is a
+        # list of tuples
+        results = {}
+        TRANSFORMS = RandomResize([(224, 448), (112, 224)], keep_ratio=True)
+        results_update = TRANSFORMS.transform(copy.deepcopy(results))
+        assert results_update['scale'][0] >= 224 and results_update['scale'][
+            0] <= 448
+        assert results_update['scale'][1] >= 112 and results_update['scale'][
+            1] <= 224
+
+        # the type of scale is invalid in init
+        with pytest.raises(NotImplementedError):
+            results = {}
+            TRANSFORMS = RandomResize([(224, 448), [112, 224]],
+                                      keep_ratio=True)
+            results_update = TRANSFORMS.transform(copy.deepcopy(results))