digital image processing question

In the lecture today (slide 44), given the filter mask on the left (the matrix with 1, 2, 1, 2, 4, 2, 1, 2, 1) and the image region on the right (the matix with 2, 3, 3, 3, 5, 5, 4, 4, 6) Q1: If we use 2D filter, count the number of addition and multiplication that we need to filter this image. \begin{tabular}{|l|l|l|} \hline 2 & 3 & 3 \\ \hline 3 & 5 & 5 \\ \hline 4 & 4 & 6 \\ \hline \end{tabular} =2+6+3=11=6+20+10=6536=4+8+6=618 Since this filter is a separable one, it can be decomposed into two filters (one column filter and one row filter) Q2: use the row filter to the image first (i.e., row-wise), and then filter the resulting image with the column filter, and count the number of addition and multiplication Q3: On slide 45, go through the complexity analysis and count the number of addition and multiplication required to filter an M-by-N image with a P-by-Q filter (kernel). That is, explain how each step in detail. For a separable filter, why is the complexity O(MN(P+Q)) by explaining 1. it requires MNP multiples and adds for the first step 2. it requires MNQ multiples and adds for the second step