/// <summary>
/// Get the color data in the region of rectangle
/// </summary>
/// <param name="bitmap">The picture you wang to get color from</param>
/// <param name="rect">The region that will be calculated</param>
/// <returns></returns>
private imgdata getData(Bitmap bitmap, Rectangle rect)
{
BitmapData data = bitmap.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int nbyte = data.Width * data.Height;
imgdata d = new imgdata(nbyte);
int index = 0;
int offset = data.Stride - bitmap.Width * 3 + rect.Left * 3 + rect.Right * 3;
unsafe
{
byte *ptr = (byte *)(void *)data.Scan0;
for (int i = 0; i < data.Height; i++)
{
for (int j = 0; j < data.Width; j++)
{
d.b[index] = *ptr;
ptr++;
d.g[index] = *ptr;
ptr++;
d.r[index] = *ptr;
ptr++;
index++;
}
ptr += offset;
}
}
bitmap.UnlockBits(data);
return(d);
}
/// <summary>
/// Get the average color in the region of rectangle
/// </summary>
/// <param name="bitmap">The picture you wang to get color from</param>
/// <param name="rect">The region that will be calculated</param>
/// <returns></returns>
public Color getAverage(Bitmap bitmap, Rectangle r)
{
imgdata d = getData(bitmap, r);
int bs = 0, gs = 0, rs = 0;
for (int i = 0; i < d.index; i++)
{
bs += d.b[i];
gs += d.g[i];
rs += d.r[i];
}
return(Color.FromArgb(rs / d.index, gs / d.index, rs / d.index));
}