Update prepro.py

Author: yzwxx

tensorlayer/prepro.py

@@ -1746,7 +1746,7 @@ def illumination(x, gamma = 1, contrast=1, saturation=1, is_random=False):
             gamma = np.random.uniform(1.0, 5.0)
         else:
             gamma = 1
-        im_ = tl.prepro.brightness(x, gamma=gamma, gain=1, is_random=False)
+        im_ = brightness(x, gamma=gamma, gain=1, is_random=False)
 
         # print("using contrast and saturation")
         image = Image.fromarray(im_) # array -> PIL
@@ -1757,7 +1757,7 @@ def illumination(x, gamma = 1, contrast=1, saturation=1, is_random=False):
         image = saturation_adjust.enhance(np.random.uniform(0.7,1.0))
         im_ = np.array(image) # PIL -> array
     else:
-        im_ = tl.prepro.brightness(im_, gamma=gamma, gain=1, is_random=False)
+        im_ = brightness(im_, gamma=gamma, gain=1, is_random=False)
         image = Image.fromarray(im_) # array -> PIL
         contrast_adjust = ImageEnhance.Contrast(image)
         image = contrast_adjust.enhance(contrast)