Used to help visualize a 2D filter. Marks local image maxima with a green '+' and minima with a red '+'. Also shows the fft response of the filter. Can optionally also plot a scanline through either center row+2 or center column+2. INPUTS F - filter to visualize plotline - if 1, then draw line through center row+2, if 2 then througt center col+2. else no line. optional. DATESTAMP 29-Sep-2005 2:00pm