refactoring and remove some public apis

mmcv/image/__init__.py

 from .io import imread, imwrite, imfrombytes
 from .transforms import (bgr2gray, gray2bgr, bgr2rgb, rgb2bgr, bgr2hsv,
                          hsv2bgr, imflip, imrotate, imcrop, impad,
-                         impad_to_multiple, imnorm, imdenorm, scale_size,
-                         imresize, imresize_like, imrescale, limit_size)
+                         impad_to_multiple, imnormalize, imdenormalize,
+                         imresize, imresize_like, imrescale)
 
 __all__ = [
     'imread', 'imwrite', 'imfrombytes', 'bgr2gray', 'gray2bgr', 'bgr2rgb',
     'rgb2bgr', 'bgr2hsv', 'hsv2bgr', 'imflip', 'imrotate', 'imcrop', 'impad',
-    'impad_to_multiple', 'imnorm', 'imdenorm', 'scale_size', 'imresize',
-    'imresize_like', 'imrescale', 'limit_size'
+    'impad_to_multiple', 'imnormalize', 'imdenormalize', 'imresize',
+    'imresize_like', 'imrescale'
 ]

mmcv/image/transforms/__init__.py

 from .colorspace import bgr2gray, gray2bgr, bgr2rgb, rgb2bgr, bgr2hsv, hsv2bgr
 from .geometry import imflip, imrotate, imcrop, impad, impad_to_multiple
-from .normalize import imnorm, imdenorm
-from .resize import scale_size, imresize, imresize_like, imrescale, limit_size
+from .normalize import imnormalize, imdenormalize
+from .resize import imresize, imresize_like, imrescale
 
 __all__ = [
     'bgr2gray', 'gray2bgr', 'bgr2rgb', 'rgb2bgr', 'bgr2hsv', 'hsv2bgr',
-    'imflip', 'imrotate', 'imcrop', 'impad', 'impad_to_multiple', 'imnorm',
-    'imdenorm', 'scale_size', 'imresize', 'imresize_like', 'imrescale',
-    'limit_size'
+    'imflip', 'imrotate', 'imcrop', 'impad', 'impad_to_multiple',
+    'imnormalize', 'imdenormalize', 'imresize', 'imresize_like', 'imrescale'
 ]

mmcv/image/transforms/normalize.py

@@ -3,14 +3,14 @@ import numpy as np
 from .colorspace import bgr2rgb, rgb2bgr
 
 
-def imnorm(img, mean, std, to_rgb=True):
+def imnormalize(img, mean, std, to_rgb=True):
     img = img.astype(np.float32)
     if to_rgb:
         img = bgr2rgb(img)
     return (img - mean) / std
 
 
-def imdenorm(img, mean, std, to_bgr=True):
+def imdenormalize(img, mean, std, to_bgr=True):
     img = (img * std) + mean
     if to_bgr:
         img = rgb2bgr(img)

mmcv/image/transforms/resize.py

@@ -3,7 +3,7 @@ from __future__ import division
 import cv2
 
 
-def scale_size(size, scale):
+def _scale_size(size, scale):
     """Rescale a size by a ratio.
 
     Args:
@@ -99,37 +99,9 @@ def imrescale(img, scale, return_scale=False, interpolation='bilinear'):
         raise TypeError(
             'Scale must be a number or tuple of int, but got {}'.format(
                 type(scale)))
-    new_size = scale_size((w, h), scale_factor)
+    new_size = _scale_size((w, h), scale_factor)
     rescaled_img = imresize(img, new_size, interpolation=interpolation)
     if return_scale:
         return rescaled_img, scale_factor
     else:
         return rescaled_img
-
-
-def limit_size(img, max_edge, return_scale=False, interpolation='bilinear'):
-    """Limit the size of an image.
-
-    If the long edge of the image is greater than max_edge, resize the image.
-
-    Args:
-        img (ndarray): The input image.
-        max_edge (int): Maximum value of the long edge.
-        return_scale (bool): Whether to return scale besides the resized image.
-        interpolation (str): Same as :func:`resize`.
-
-    Returns:
-        tuple or ndarray: (resized_img, scale_factor) or resized_img.
-    """
-    h, w = img.shape[:2]
-    if max(h, w) > max_edge:
-        scale = float(max_edge) / max(h, w)
-        new_size = scale_size((w, h), scale)
-        resized_img = imresize(img, new_size, interpolation=interpolation)
-    else:
-        scale = 1.0
-        resized_img = img
-    if return_scale:
-        return resized_img, scale
-    else:
-        return resized_img

tests/test_image.py

@@ -110,10 +110,6 @@ class TestImage(object):
                 computed_hsv[i, j, :] = [h, s, v]
         assert_array_almost_equal(out_img, computed_hsv, decimal=2)
 
-    def test_scale_size(self):
-        assert mmcv.scale_size((300, 200), 0.5) == (150, 100)
-        assert mmcv.scale_size((11, 22), 0.7) == (8, 15)
-
     def test_imresize(self):
         resized_img = mmcv.imresize(self.img, (1000, 600))
         assert resized_img.shape == (600, 1000, 3)
@@ -158,26 +154,6 @@ class TestImage(object):
         with pytest.raises(TypeError):
             mmcv.imrescale(self.img, [100, 100])
 
-    def test_limit_size(self):
-        # limit to 800
-        resized_img = mmcv.limit_size(self.img, 800)
-        assert resized_img.shape == (300, 400, 3)
-        resized_img, scale = mmcv.limit_size(self.img, 800, True)
-        assert resized_img.shape == (300, 400, 3) and scale == 1
-
-        # limit to 200
-        resized_img = mmcv.limit_size(self.img, 200)
-        assert resized_img.shape == (150, 200, 3)
-        resized_img, scale = mmcv.limit_size(self.img, 200, True)
-        assert resized_img.shape == (150, 200, 3) and scale == 0.5
-
-        # test with img rather than img path
-        img = mmcv.imread(self.img)
-        resized_img = mmcv.limit_size(img, 200)
-        assert resized_img.shape == (150, 200, 3)
-        resized_img, scale = mmcv.limit_size(img, 200, True)
-        assert resized_img.shape == (150, 200, 3) and scale == 0.5
-
     def test_imflip(self):
         # test horizontal flip (color image)
         img = np.random.rand(80, 60, 3)