I have a fucntion that create histogram of each Bitmap. How can i create another 3 histograms for R.G.B of each Bitmap?
- by Daniel Lip
This is the histogram function im using today and if im not worng it's creating an histogram by Gray color.
What i want is another fucntion that will return me 3 histograms of each Bitmap:
The first histogram will be of the Red color of the bitmap the second for the Green color and the last one for the Blue color.
public static long[] GetHistogram(Bitmap b)
{
long[] myHistogram = new long[256];
BitmapData bmData = null;
try
{
//Lock it fixed with 32bpp
bmData = b.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
int scanline = bmData.Stride;
System.IntPtr Scan0 = bmData.Scan0;
unsafe
{
byte* p = (byte*)(void*)Scan0;
int nWidth = b.Width;
int nHeight = b.Height;
for (int y = 0; y < nHeight; y++)
{
for (int x = 0; x < nWidth; x++)
{
long Temp = 0;
Temp += p[0]; // p[0] - blue, p[1] - green , p[2]-red
Temp += p[1];
Temp += p[2];
Temp = (int)Temp / 3;
myHistogram[Temp]++;
//we do not need to use any offset, we always can increment by pixelsize when
//locking in 32bppArgb - mode
p += 4;
}
}
}
b.UnlockBits(bmData);
}
catch
{
try
{
b.UnlockBits(bmData);
}
catch
{
}
}
return myHistogram;
}
How may i do it ?
