image = MakeSincImage(freq,i0,j0,nRowPixels,[nColPixels])
Computes a two-dimensional sinc function image.
The sinc function has cut-off frequency freq
(in cycles/image) and is positioned at (i0,j0).
The image has dimensions nRowPixels by nColPixels.
If nColPixels is omitted, a square image is returned.
8/15/94 dhb Added optional column pixels argument.
10/28/98 dhb Change to call Matlab sinc rather than my Sinc.