doc for prefetch. brightnessadd -> brightness

examples/ResNet/cifar10_resnet.py

@@ -131,7 +131,7 @@ def get_data(train_or_test):
             imgaug.CenterPaste((40, 40)),
             imgaug.RandomCrop((32, 32)),
             imgaug.Flip(horiz=True),
-            #imgaug.BrightnessAdd(20),
+            #imgaug.Brightness(20),
             #imgaug.Contrast((0.6,1.4)),
             imgaug.MapImage(lambda x: x - pp_mean),
         ]

examples/ResNet/svhn_resnet.py

@@ -134,7 +134,7 @@ def get_data(train_or_test):
             imgaug.CenterPaste((40, 40)),
             imgaug.RandomCrop((32, 32)),
             #imgaug.Flip(horiz=True),
-            imgaug.BrightnessAdd(10),
+            imgaug.Brightness(10),
             imgaug.Contrast((0.8,1.2)),
             imgaug.GaussianDeform(  # this is slow
                 [(0.2, 0.2), (0.2, 0.8), (0.8,0.8), (0.8,0.2)],

examples/cifar10_convnet.py

@@ -82,7 +82,7 @@ def get_data(train_or_test):
         augmentors = [
             imgaug.RandomCrop((30, 30)),
             imgaug.Flip(horiz=True),
-            imgaug.BrightnessAdd(63),
+            imgaug.Brightness(63),
             imgaug.Contrast((0.2,1.8)),
             imgaug.GaussianDeform(
                 [(0.2, 0.2), (0.2, 0.8), (0.8,0.8), (0.8,0.2)],

examples/svhn_digit_convnet.py

@@ -76,7 +76,7 @@ def get_config():
 
     augmentors = [
         imgaug.Resize((40, 40)),
-        imgaug.BrightnessAdd(30),
+        imgaug.Brightness(30),
         imgaug.Contrast((0.5,1.5)),
         imgaug.GaussianDeform(  # this is slow
             [(0.2, 0.2), (0.2, 0.8), (0.8,0.8), (0.8,0.2)],

tensorpack/dataflow/base.py

@@ -26,7 +26,10 @@ class DataFlow(object):
 
     def reset_state(self):
         """
-        Reset state of the dataflow (usually the random seed)
+        Reset state of the dataflow,
+        for example, RNG **HAS** to be reset here if used in the DataFlow.
+        Otherwise it may not work well with prefetching, because different
+        processes will have the same RNG state.
         """
         pass
 

tensorpack/dataflow/imgaug/imgproc.py

@@ -5,9 +5,9 @@
 from .base import ImageAugmentor
 import numpy as np
 
-__all__ = ['BrightnessAdd', 'Contrast', 'MeanVarianceNormalize']
+__all__ = ['Brightness', 'Contrast', 'MeanVarianceNormalize']
 
-class BrightnessAdd(ImageAugmentor):
+class Brightness(ImageAugmentor):
     """
     Random adjust brightness.
     """

tensorpack/dataflow/prefetch.py

@@ -20,6 +20,7 @@ class PrefetchProcess(multiprocessing.Process):
         self.queue = queue
 
     def run(self):
+        # reset RNG of ds so each process will produce different data
         self.ds.reset_state()
         while True:
             for dp in self.ds.get_data():