After convolving, we would divide by the filter values sum in order to calculate the final pixel value? So for the 3x3 box filter, after convolving, we would divide by $\frac{1}{9}$ in order to come up with the corresponding pixel value?

byi

^I imagine that this would only make sense if you want to maintain the same average intensity in the input/output? (for example, blurring or sharpening)

It seems very reasonable to have filters where this doesn't make sense; a finite difference filter, for example, would have values that sum to 0.

masoudc

How would blurring and sharpening maintain the average intensity of input/output? Would the reduction in d_color not reduce intensity?

After convolving, we would divide by the filter values sum in order to calculate the final pixel value? So for the 3x3 box filter, after convolving, we would divide by $\frac{1}{9}$ in order to come up with the corresponding pixel value?