The screenshot is from the 1st assignment of Course 4… Just a bit confused about the dimension of W (filter)…
Hi Wz111,
The convolutions are over volume using filters. To convolve over the input volume the volume of a filter is filter size x filter size x depth of input volume. This is fxfxn__C_prev. Now the depth of the output volume is determined by the number of filters. So n_C indicates the number of filters used, which is equal to the depth of the output volume.
I hope this clarifies things.