How do I gaussian blur an image without using any in-built gaussian functions?

Question

I want to blur my image using the native Gaussian blur formula. I read the Wikipedia article, but I am not sure how to implement this.

How do I use the formula to de

Answer 1

Here's the pseudo-code for the code I used in C# to calculate the kernel. I do not dare say that I treat the end-conditions correctly, though:

double[] kernel = new double[radius * 2 + 1];
double twoRadiusSquaredRecip = 1.0 / (2.0 * radius * radius);
double sqrtTwoPiTimesRadiusRecip = 1.0 / (sqrt(2.0 * Math.PI) * radius);
double radiusModifier = 1.0;

int r = -radius;
for (int i = 0; i < kernel.Length; i++)
{
    double x = r * radiusModifier;
    x *= x;
    kernel[i] = sqrtTwoPiTimesRadiusRecip * Exp(-x * twoRadiusSquaredRecip);
    r++;
}

double div = Sum(kernel);
for (int i = 0; i < kernel.Length; i++)
{
    kernel[i] /= div;
}

Hope this helps.