add increasing in solarize and posterize

mmcls/datasets/pipelines/auto_augment.py

@@ -510,18 +510,23 @@ class Solarize(object):
 
     Args:
         thr (int | float): The threshold above which the pixels value will be
-            inverted.
+            inverted when incresing is set to False.
         prob (float): The probability for solarizing therefore should be in
             range [0, 1]. Defaults to 0.5.
+        increasing (bool): When setting to True, the meaning of thr is 
+            8 - actual thr.
     """
 
-    def __init__(self, thr, prob=0.5):
+    def __init__(self, thr, prob=0.5, increasing=False):
         assert isinstance(thr, (int, float)), 'The thr type must '\
             f'be int or float, but got {type(thr)} instead.'
         assert 0 <= prob <= 1.0, 'The prob should be in range [0,1], ' \
             f'got {prob} instead.'
 
-        self.thr = thr
+        if increasing:
+            self.thr = 256 - thr
+        else:
+            self.thr = thr
         self.prob = prob
 
     def __call__(self, results):
@@ -588,18 +593,23 @@ class Posterize(object):
     """Posterize images (reduce the number of bits for each color channel).
 
     Args:
-        bits (int | float): Number of bits for each pixel in the output img,
-            which should be less or equal to 8.
+        bits (int | float): Number of bits for each pixel in the output img 
+            when increasing is False, which should be less or equal to 8.
         prob (float): The probability for posterizing therefore should be in
             range [0, 1]. Defaults to 0.5.
+        increasing (bool): When setting to True, the meaning of bits is 
+            8 - actual number of bits.
     """
 
-    def __init__(self, bits, prob=0.5):
+    def __init__(self, bits, prob=0.5, increasing=False):
         assert bits <= 8, f'The bits must be less than 8, got {bits} instead.'
         assert 0 <= prob <= 1.0, 'The prob should be in range [0,1], ' \
             f'got {prob} instead.'
 
-        self.bits = int(bits)
+        if increasing:
+            self.bits = 8 - int(bits)
+        else:
+            self.bits = int(bits)
         self.prob = prob
 
     def __call__(self, results):

tests/test_pipelines/test_auto_augment.py

@@ -727,6 +727,18 @@ def test_solarize():
     assert (results['img'] == img_solarized).all()
     assert (results['img'] == results['img2']).all()
 
+    # test case when thr=156
+    results = construct_toy_data_photometric()
+    transform = dict(type='Solarize', thr=156, prob=1., increasing=True)
+    pipeline = build_from_cfg(transform, PIPELINES)
+    results = pipeline(results)
+    img_solarized = np.array([[0, 127, 0], [1, 128, 1], [2, 126, 2]],
+                             dtype=np.uint8)
+    img_solarized = np.stack([img_solarized, img_solarized, img_solarized],
+                             axis=-1)
+    assert (results['img'] == img_solarized).all()
+    assert (results['img'] == results['img2']).all()
+
 
 def test_solarize_add():
     # test assertion for invalid type of magnitude
@@ -822,6 +834,18 @@ def test_posterize():
     assert (results['img'] == img_posterized).all()
     assert (results['img'] == results['img2']).all()
 
+    # test case when bits=5, incresing= True
+    results = construct_toy_data_photometric()
+    transform = dict(type='Posterize', bits=5, prob=1., increasing=True)
+    pipeline = build_from_cfg(transform, PIPELINES)
+    results = pipeline(results)
+    img_posterized = np.array([[0, 128, 224], [0, 96, 224], [0, 128, 224]],
+                              dtype=np.uint8)
+    img_posterized = np.stack([img_posterized, img_posterized, img_posterized],
+                              axis=-1)
+    assert (results['img'] == img_posterized).all()
+    assert (results['img'] == results['img2']).all()
+
 
 def test_contrast(nb_rand_test=100):