> I'm old enough to know better, but I cannot get my head round this and it's
Looks like you're only working in one channel which is why your resulting image is coming out red as opposed to
greyscale - Remember that in high/true colour, pixels are stored as Red, Green, Blue [, Alpha] so you have either 3 or 4
channels to operate on per pixel.
Have a look at the "Edge detection / Edge snap / Filter kernel" demo on my site, which provides code for running a
simple 3*3 filter kernel over an image. It should be a fairly trivial task to add this to support your 9*9 Gaussian
kernel rather than rolling your own from scratch. Also remember that a Gaussian Kernel is separable and commutative so
two passes of 1*9 and 9*1 will yield the same result as one 9*9 kernel, but with a lot less processing.
Hope this helps,
- Microsoft Visual Basic MVP -