MATLAB: Error while transferring weights of a trained CNN network to an empty CNN network

errorMATLAB

Hi,
I am trying to transfer the weights of layer 11 from 'original_net' to layer 11 of 'layers_final'. Both have same structure and 'layer_final' is just the empty, untrained version of 'original net'. i am using the following command:
Layers_final(11).Weights = net_1.Layers(11).Weights
I get the following error while doing so:
Error using nnet.cnn.layer.TransposedConvolution2DLayer/set.Weights (line 204)
Expected input to be of size 4x4x8x1, but it is of size 4x4x8x8.
code for layers_final:
imageLayer_final = imageInputLayer([32,32,1]);
encodingLayers_final = [ ...
    convolution2dLayer(3,16,'Padding','same'), ...
    reluLayer, ...
    maxPooling2dLayer(2,'Padding','same','Stride',2), ...
    convolution2dLayer(3,8,'Padding','same'), ...
    reluLayer, ...
    maxPooling2dLayer(2,'Padding','same','Stride',2), ...
    convolution2dLayer(3,8,'Padding','same'), ...
    reluLayer, ...
    maxPooling2dLayer(2,'Padding','same','Stride',2)];
decodingLayers_final = [ ...
    createUpsampleTransponseConvLayer(2,8), ...
    reluLayer, ...
    createUpsampleTransponseConvLayer(2,8), ...
    reluLayer, ...
    createUpsampleTransponseConvLayer(2,16), ...
    reluLayer, ...
    convolution2dLayer(3,1,'Padding','same'), ...
    clippedReluLayer(1.0), ...
    regressionLayer];
layers_final = [imageLayer,encodingLayers,decodingLayers];
net_original attached with the question.
Thanks

Best Answer

If the function createUpsampleTransponseConvLayer is the helper function from the example Prepare Datastore for Image-to-Image Regression then change the 'NumChannels' Name-Value Pair Argument to 'auto' or don't mention it in the transposedConv2dLayer function. 
% helper function from the example Prepare Datastore for Image-to-Image Regression
function out = createUpsampleTransponseConvLayer(factor,numFilters)
filterSize = 2*factor - mod(factor,2); 
cropping = (factor-mod(factor,2))/2;
numChannels = 1;
out = transposedConv2dLayer(filterSize,numFilters, ... 
    'NumChannels',numChannels,'Stride',factor,'Cropping',cropping);
end
Since the layer is defined with 'NumChannels' (number of channels of the input to this transposedConv2dLayer) as 1 hence it can accept wieghts of size "filterSize x filterSize x numFilters x numChannels" which is 4x4x8x1 in this case.
Change the function as follows:
function out = createUpsampleTransponseConvLayer(factor,numFilters)
filterSize = 2*factor - mod(factor,2); 
cropping = (factor-mod(factor,2))/2;
out = transposedConv2dLayer(filterSize,numFilters, ... 
    'Stride',factor,'Cropping',cropping);
end
and then define the layers.
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