def test_adjust_contrast(self, nb_rand_test=100):
def _adjust_contrast(img, factor):
from PIL.ImageEnhance import Contrast
from PIL import Image
# Image.fromarray defaultly supports RGB, not BGR.
# convert from BGR to RGB
img = Image.fromarray(img[..., ::-1], mode='RGB')
contrasted_img = Contrast(img).enhance(factor)
# convert from RGB to BGR
return np.asarray(contrasted_img)[..., ::-1]
img = np.array([[0, 128, 255], [1, 127, 254], [2, 129, 253]],
dtype=np.uint8)
img = np.stack([img, img, img], axis=-1)
# test case with factor 1.0
assert_array_equal(mmcv.adjust_contrast(img, 1.), img)
# test case with factor 0.0
assert_array_equal(mmcv.adjust_contrast(img, 0.),
_adjust_contrast(img, 0.))
# test adjust_contrast with randomly sampled images and factors.
for _ in range(nb_rand_test):
img = np.clip(
np.random.uniform(0, 1, (1200, 1000, 3)) * 260, 0,
255).astype(np.uint8)
factor = np.random.uniform()
# Note the gap (less_equal 1) between PIL.ImageEnhance.Contrast
# and mmcv.adjust_contrast comes from the gap that converts from
# a color image to gray image using mmcv or PIL.
np.testing.assert_allclose(
mmcv.adjust_contrast(img, factor).astype(np.int32),
_adjust_contrast(img, factor).astype(np.int32),
rtol=0,
atol=1)
def __call__(self, results):
if np.random.rand() > self.prob:
return results
magnitude = random_negative(self.magnitude, self.random_negative_prob)
for key in results.get('img_fields', ['img']):
img = results[key]
img_contrasted = mmcv.adjust_contrast(img, factor=1 + magnitude)
results[key] = img_contrasted.astype(img.dtype)
return results
def __call__(self, results):
for i, modal in enumerate(results['modality']):
if modal == 'rgb':
video = results['video'][i]
bright = np.random.uniform(max(0, 1 - self.brightness),
1 + self.brightness)
contrast = np.random.uniform(max(0, 1 - self.contrast),
1 + self.contrast)
video = mmcv.adjust_brightness(video.astype(np.int32), bright)
num_frames = video.shape[0]
video = video.astype(np.uint8).reshape(-1, video.shape[2], 3)
video = mmcv.adjust_contrast(video, contrast).reshape(
num_frames, -1, video.shape[1], 3)
results['video'][i] = video
return results
def _adjust_contrast_img(self, results, factor=1.0):
"""Adjust the image contrast."""
for key in results.get('img_fields', ['img']):
img = results[key]
results[key] = mmcv.adjust_contrast(img, factor).astype(img.dtype)
