# Choosing layer hyper-parameters of a CNN

Context: I'm building a CNN on MATLAB to classify wallpaper groups.

I'm using the following network type.

CONV -> ReLU -> POOL -> CONV -> ReLU -> POOL -> FC -> DROPOUT -> FC -> SOFTMAX

Should the parameters for the first CONV or POOL layers be the same as the second (or later) CONV or POOL layers succeeding it? If not, is there a meaningful way to choose parameters for the repeated succeeding layers?

For example, for the first CONV layer you may pick a 5x5 filter. Perhaps for the second CONV layer it's more meaningful to pick a certain different size filter?

Finding an appropriate architecture is somehow practical. Those hyper-parameters you are talking may be different. Try to use a base architecture and then train your model. If it does not learn your model try to change the hyper parameters. It is an iterative operation to find a good model. There are a lot of debates, but there is not exactly consensus for making good models in CNNs. You can think of if your model does not learn your data, it needs more features to be learned by the CNN. The behavior of the layers are somehow as follows: