Update pooling shape attribute before reaching pooling node.

Source/CNTKv2LibraryDll/Function.cpp

@@ -782,6 +782,8 @@ namespace CNTK
                 NDShape outputMapCount = { 1 };
                 std::vector<bool> sharing = { true };
                 outputShape = ConvolutionOpOutputShape(op, inputs[0].Shape(), poolingWindowsShape, outputMapCount, strides, sharing, autoPadding, lowerPad, upperPad, false, inferDimensions);
+
+                functionConfig[PrimitiveFunction::AttributeNamePoolingWindowShape] = poolingWindowsShape;
                 break;
             }
             case PrimitiveOpType::SumAll:

Source/ComputationNetworkLib/ConvolutionalNodes.h

@@ -783,10 +783,6 @@ public:
 
         const auto& inputShape = GetInputSampleLayout(0);
 
-        // In case of pooling if the kernel shape is unknown, then treat it as global pooling.
-        if (m_kernelShape == NDShape::Unknown)
-            m_kernelShape = inputShape.SubShape(0, inputShape.Rank()-1);
-
         // infer reduction dimensions if not given
         InferReductionDims(inputShape, TensorShape());
 

bindings/python/cntk/layers.py

@@ -171,11 +171,12 @@ def Convolution(filter_shape,        # e.g. (3,3)
     apply_x = apply_x >> activation
     return Block(apply_x, 'Convolution', Record(W=W, b=b))
 
-# MaxPooling, AveragePooling -- create a max- or average-pooling layer
-# TODO: do we need MaxPooling and AveragePooling?
-# TODO: This is not really a layer as it does not hold learnable parameters. So:
-#  - keep it in layer format, since users may think about it this way?
-#  - turn it into a function (lower-case)? Then how would it work inside Sequential() (we'd need partial application)?
+# Create a Pooling layer with one of following types:
+#
+#   MaxPooling and GlobalMaxPooling
+#   AveragePooling and GlobalAveragePooling
+#
+# Setting the filter_shape to None, mean global pooling.
 from cntk.cntk_py import PoolingType_Max, PoolingType_Average
 def Pooling(op,      # PoolingType_Max or _Average
             filter_shape,  # e.g. (3,3)
@@ -192,21 +193,25 @@ def Pooling(op,      # PoolingType_Max or _Average
         raise ValueError('Pooling: op must be PoolingType_Max or PoolingType_average')
     return Block(apply_x, op_name)
 
+# MaxPooling
 def MaxPooling(filter_shape,  # e.g. (3,3)
                strides=1,
                pad=False):
     return Pooling(PoolingType_Max, filter_shape, strides=strides, pad=pad)
 
+# AveragePooling
 def AveragePooling(filter_shape,  # e.g. (3,3)
                    strides=1,
                    pad=False):
     return Pooling(PoolingType_Average, filter_shape, strides=strides, pad=pad)
 
+# GlobalMaxPooling
 def GlobalMaxPooling():
-    return Pooling(PoolingType_Max, None)
+    return Pooling(PoolingType_Max, None, pad=False)
 
+# GlobalAveragePooling
 def GlobalAveragePooling():
-    return Pooling(PoolingType_Average, None)
+    return Pooling(PoolingType_Average, None, pad=False)
 
 # Recurrence() -- run a block recurrently over a time sequence
 def Recurrence(over, go_backwards=False, initial_state=initial_state_default_or_None):

bindings/python/examples/CifarResNet/CifarResNet.py

@@ -9,7 +9,7 @@ import math
 import numpy as np
 
 from cntk.blocks import default_options
-from cntk.layers import Convolution, GlobalAveragePooling, Dropout, BatchNormalization, Dense
+from cntk.layers import Convolution, AveragePooling, GlobalAveragePooling, Dropout, BatchNormalization, Dense
 from cntk.models import Sequential, LayerStack
 from cntk.utils import *
 from cntk.io import MinibatchSource, ImageDeserializer, StreamDef, StreamDefs