Speed up Matrix Addition in C#

Question

I\'d like to optimize this piece of code :

public void PopulatePixelValueMatrices(GenericImage image,int Width, int Height)
{            
        for (int x = 0;         


        

Answer 1

Although it's a micro-optimization and thus may not add much you might want to study what the likelihood is of getting a zero when you do

Byte  pixelValue = image.GetPixel(x, y).B;

Clearly, if pixelValue = 0 then there's no reason to do the summations so your routine might become

public void PopulatePixelValueMatrices(GenericImage image,int Width, int Height)
  {
  for (int x = 0; x < Width; x++)
    {
    for (int y = 0; y < Height; y++)
      {
       Byte  pixelValue = image.GetPixel(x, y).B;

       if(pixelValue != 0)
         {
         this.sumOfPixelValues[x, y] += pixelValue;
         this.sumOfPixelValuesSquared[x, y] += pixelValue * pixelValue;
         }}}}

However, the question is how often you're going to see pixelValue=0, and whether the saving on the compute-and-store will offset the cost of the test.