Does a maxpooling layer reduce the number of parameters in a network?












0















I have a simple network defined:



model = Sequential()
model.add(Conv1D(5, 3, activation='relu', input_shape=(10, 1),name="conv1",padding="same"))
model.add(MaxPooling1D())
model.add(Conv1D(5, 3, activation='relu',name="conv2",padding="same"))
model.add(MaxPooling1D())
model.add(Dense(1, activation='relu',name="dense1"))
model.compile(loss='mse', optimizer='rmsprop')


The shape of the layers is as follows:



conv1-(None, 10, 5)

max1-(None, 5, 5)

conv2-(None,5,5)

max2-(None,2,5)

dense1-(None,2,1)


The model has a total of 106 parameters, however if I remove max pooling layer then the model summary looks as follows:



conv1-(None, 10, 5) 

conv2-(None,10,5)

dense1-(None,10,1)


In both the cases total parameters remain 106, but why is it commonly written that the max-pooling layer reduces the number of parameters?










share|improve this question





























    0















    I have a simple network defined:



    model = Sequential()
    model.add(Conv1D(5, 3, activation='relu', input_shape=(10, 1),name="conv1",padding="same"))
    model.add(MaxPooling1D())
    model.add(Conv1D(5, 3, activation='relu',name="conv2",padding="same"))
    model.add(MaxPooling1D())
    model.add(Dense(1, activation='relu',name="dense1"))
    model.compile(loss='mse', optimizer='rmsprop')


    The shape of the layers is as follows:



    conv1-(None, 10, 5)

    max1-(None, 5, 5)

    conv2-(None,5,5)

    max2-(None,2,5)

    dense1-(None,2,1)


    The model has a total of 106 parameters, however if I remove max pooling layer then the model summary looks as follows:



    conv1-(None, 10, 5) 

    conv2-(None,10,5)

    dense1-(None,10,1)


    In both the cases total parameters remain 106, but why is it commonly written that the max-pooling layer reduces the number of parameters?










    share|improve this question



























      0












      0








      0








      I have a simple network defined:



      model = Sequential()
      model.add(Conv1D(5, 3, activation='relu', input_shape=(10, 1),name="conv1",padding="same"))
      model.add(MaxPooling1D())
      model.add(Conv1D(5, 3, activation='relu',name="conv2",padding="same"))
      model.add(MaxPooling1D())
      model.add(Dense(1, activation='relu',name="dense1"))
      model.compile(loss='mse', optimizer='rmsprop')


      The shape of the layers is as follows:



      conv1-(None, 10, 5)

      max1-(None, 5, 5)

      conv2-(None,5,5)

      max2-(None,2,5)

      dense1-(None,2,1)


      The model has a total of 106 parameters, however if I remove max pooling layer then the model summary looks as follows:



      conv1-(None, 10, 5) 

      conv2-(None,10,5)

      dense1-(None,10,1)


      In both the cases total parameters remain 106, but why is it commonly written that the max-pooling layer reduces the number of parameters?










      share|improve this question
















      I have a simple network defined:



      model = Sequential()
      model.add(Conv1D(5, 3, activation='relu', input_shape=(10, 1),name="conv1",padding="same"))
      model.add(MaxPooling1D())
      model.add(Conv1D(5, 3, activation='relu',name="conv2",padding="same"))
      model.add(MaxPooling1D())
      model.add(Dense(1, activation='relu',name="dense1"))
      model.compile(loss='mse', optimizer='rmsprop')


      The shape of the layers is as follows:



      conv1-(None, 10, 5)

      max1-(None, 5, 5)

      conv2-(None,5,5)

      max2-(None,2,5)

      dense1-(None,2,1)


      The model has a total of 106 parameters, however if I remove max pooling layer then the model summary looks as follows:



      conv1-(None, 10, 5) 

      conv2-(None,10,5)

      dense1-(None,10,1)


      In both the cases total parameters remain 106, but why is it commonly written that the max-pooling layer reduces the number of parameters?







      keras conv-neural-network max-pooling






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 26 '18 at 17:21









      Daniel Möller

      35.7k667104




      35.7k667104










      asked Nov 26 '18 at 17:14









      vampiretapvampiretap

      565




      565
























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          Which kind of network? It's all up to you.




          • Conv layers: no

          • Dense layers:


            • Directly after Conv or Pooling:


              • With "channels_last": no

              • With "channels_first": yes



            • After Flatten layers: yes

            • After GlobalPooling layers: no




          Your network: no.



          Explanations




          • Poolings and GlobalPoolings change the image sizes, but don't change the number of channels

          • Conv layers are fixed size filters that stride along the images.The filter size is independent of the image size, thus there is no change. Filters depend on kernel size and channels

          • Dense layers work on the last dimension only.


            • If the last dimension is channels, the pooling layers don't affect it

            • If the last dimension is an image side, it's affected



          • Flatten layers transform the image sizes and channels into a single dimension.






          share|improve this answer























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            1 Answer
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            active

            oldest

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            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            0














            Which kind of network? It's all up to you.




            • Conv layers: no

            • Dense layers:


              • Directly after Conv or Pooling:


                • With "channels_last": no

                • With "channels_first": yes



              • After Flatten layers: yes

              • After GlobalPooling layers: no




            Your network: no.



            Explanations




            • Poolings and GlobalPoolings change the image sizes, but don't change the number of channels

            • Conv layers are fixed size filters that stride along the images.The filter size is independent of the image size, thus there is no change. Filters depend on kernel size and channels

            • Dense layers work on the last dimension only.


              • If the last dimension is channels, the pooling layers don't affect it

              • If the last dimension is an image side, it's affected



            • Flatten layers transform the image sizes and channels into a single dimension.






            share|improve this answer




























              0














              Which kind of network? It's all up to you.




              • Conv layers: no

              • Dense layers:


                • Directly after Conv or Pooling:


                  • With "channels_last": no

                  • With "channels_first": yes



                • After Flatten layers: yes

                • After GlobalPooling layers: no




              Your network: no.



              Explanations




              • Poolings and GlobalPoolings change the image sizes, but don't change the number of channels

              • Conv layers are fixed size filters that stride along the images.The filter size is independent of the image size, thus there is no change. Filters depend on kernel size and channels

              • Dense layers work on the last dimension only.


                • If the last dimension is channels, the pooling layers don't affect it

                • If the last dimension is an image side, it's affected



              • Flatten layers transform the image sizes and channels into a single dimension.






              share|improve this answer


























                0












                0








                0







                Which kind of network? It's all up to you.




                • Conv layers: no

                • Dense layers:


                  • Directly after Conv or Pooling:


                    • With "channels_last": no

                    • With "channels_first": yes



                  • After Flatten layers: yes

                  • After GlobalPooling layers: no




                Your network: no.



                Explanations




                • Poolings and GlobalPoolings change the image sizes, but don't change the number of channels

                • Conv layers are fixed size filters that stride along the images.The filter size is independent of the image size, thus there is no change. Filters depend on kernel size and channels

                • Dense layers work on the last dimension only.


                  • If the last dimension is channels, the pooling layers don't affect it

                  • If the last dimension is an image side, it's affected



                • Flatten layers transform the image sizes and channels into a single dimension.






                share|improve this answer













                Which kind of network? It's all up to you.




                • Conv layers: no

                • Dense layers:


                  • Directly after Conv or Pooling:


                    • With "channels_last": no

                    • With "channels_first": yes



                  • After Flatten layers: yes

                  • After GlobalPooling layers: no




                Your network: no.



                Explanations




                • Poolings and GlobalPoolings change the image sizes, but don't change the number of channels

                • Conv layers are fixed size filters that stride along the images.The filter size is independent of the image size, thus there is no change. Filters depend on kernel size and channels

                • Dense layers work on the last dimension only.


                  • If the last dimension is channels, the pooling layers don't affect it

                  • If the last dimension is an image side, it's affected



                • Flatten layers transform the image sizes and channels into a single dimension.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 26 '18 at 17:20









                Daniel MöllerDaniel Möller

                35.7k667104




                35.7k667104
































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