Inception Network Motivation - computation error

Hi,
In week 2, Inception Network Motivation, Prof. Andrew does the calculations below for the second layer which I’ve highlighted it:


However, if we look at the computations before that (fore the prev layer) we can see that the multlipication might have to change to this:
(28*28*16)*(5*5*32)
because we have 32 filters not 16

But I’m not sure. Please help. Thanks a lot

Well, multiplication is commutative and associative, right? So the answer will be the same in either case. BTW you wrote 18 there, but must have meant 16.

But the real issue here is that the notation he’s using is just a bit confusing. Notice where the commas are under the heading CONV between the boxes. So in the first one, what he’s saying is that the filters are 1 x 1 comma and there are 16 of them. And each of those 16 filters has the shape 1 x 1 x 192. Then in the second case, he’s saying that the filters are 5 x 5 comma and there are 32 of them, and each of them is shape 5 x 5 x 16.

But as commented at the beginning, the answer is the same in either case …

Thanks for the correction about 16.
And yes I dont’t know why I did’t pay enought heed to it :)))
Thanks a lot