Got confused after I extracted weights from Trained caffenet

问题

So basically this are the dimensions of the weights from trained caffenet:

conv1: (96,3,11,11) conv2: (256,48,5,5) conv3:(384,256,3,3) conv4: (384,192,3,3) conv5:(256, 192, 3 , 3)

I am confused that although conv1 gives 96 channels as output why does conv2 only considers 48 while convolution? Am I missing something?

回答1:

Yes, you missed the parameter 'group'. The convolution_param defined in the conv2 layer is given below.You can find out that parameter group is set to 2 as grouping the convolution layer can save gpu memory.

 convolution_param {
 num_output: 256
 pad: 2
 kernel_size: 5
 group: 2
 weight_filler {
  type: "gaussian"
  std: 0.01
 }
 bias_filler {
  type: "constant"
  value: 1
 }

来源：https://stackoverflow.com/questions/49056430/got-confused-after-i-extracted-weights-from-trained-caffenet