/// <summary>
/// Computes the avarange grayscale value of a certain bitmap region.
/// </summary>
/// <param name="grayscaleBitmap">A grayscale bitmap.</param>
/// <param name="rectangle">Defines a region.</param>
/// <returns></returns>
public static int GetAvarageGrayscale(Graphic grayscaleBitmap, System.Drawing.Rectangle rectangle)
{
int average=0;
try
{
for(int y=rectangle.Y; y<rectangle.Bottom; y++)
for(int x=rectangle.X; x<rectangle.Right; x++)
{
average+=grayscaleBitmap.GetPixel(x, y).R;
}
}
catch(System.Exception ex)
{
return 128;
}
return average/(rectangle.Width*rectangle.Height);
}
/////////////////////////////////////////////////////////////////
// noch mehr Bildverarbeitung
/////////////////////////////////////////////////////////////////
public double Compare(Graphic ImageToCompare, uint Threshold)
{
if(ImageToCompare==null) throw new Exception("Image is null");
if(Width!=ImageToCompare.Width) throw new Exception("Image have different sizes");
if(Height!=ImageToCompare.Height) throw new Exception("Image have different sizes");
if(channelFormat!=ImageToCompare.channelFormat) throw new Exception("Image have different formats");
uint divergency=0;
for(uint y=0; y<Width; y++)
{
for(uint x=0; x<Height; x++)
{
Color picA=GetPixel(x, y);
Color picB=ImageToCompare.GetPixel(x, y);
int dif=0;
dif+=System.Math.Abs(picA.R-picB.R);
dif+=System.Math.Abs(picA.G-picB.G);
dif+=System.Math.Abs(picA.B-picB.B);
dif/=3;
if(dif>Threshold) divergency++;
}
}
//Gibt in % zurück wie stark die Bilder von einander abweichen
//0 % == Bilder sind Identisch
return (double)(100*(divergency/(double)(Width*Height)));
}