In the above example we have an input matrix of dimension \( 3\times 3 \). In general we call the input for an input volume and it is defined by its width \( H_1 \), height \( H_1 \) and depth \( D_1 \). If we have the standard three color channels \( D_1=3 \).
The above example has \( W_1=H_1=3 \) and \( D_1=1 \).
When we introduce the filter we have the following additional hyperparameters
These parameters are defined by the architecture of the network and are not included in the training.