Sharpen on a Bitmap using C#

Question

I want to put a sharpen filter on an image. I have found a web with short tutorial. I tried to do it in C# so here is my code. Anyway, I tried to find out why it is not work

Answer 1

This will create a softer sharpening effect. You can expand the filter array if you need to, or change the 16 to something larger, but I found this isn't as harsh as the one you have.

const int filterWidth = 5;
const int filterHeight = 5;

double[,] filter = new double[filterWidth,filterHeight] {
    { -1, -1, -1, -1, -1 },
    { -1,  2,  2,  2, -1 },
    { -1,  2,  16,  2, -1 },
    { -1,  2,  2,  2, -1 },
    { -1, -1, -1, -1, -1 }
};

double factor = 1.0 / 16.0;