/// <summary>
/// 图片黑白处理
/// </summary>
/// <param name="bmp"></param>
/// <param name="type"></param>
/// <returns></returns>
public static Bitmap GrayImage(Bitmap bmp, int type)
{
int height = bmp.Height;
int width = bmp.Width;
Bitmap newbmp = new Bitmap(width, height);
LockBitmap lbmp = new LockBitmap(bmp);
LockBitmap newlbmp = new LockBitmap(newbmp);
lbmp.LockBits();
newlbmp.LockBits();
Color pixel;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
pixel = lbmp.GetPixel(x, y);
int r, g, b, Result = 0;
r = pixel.R;
g = pixel.G;
b = pixel.B;
switch (type)
{
case 0: //平均值法
Result = ((r + g + b) / 3);
break;
case 1: //最大值法
Result = r > g ? r : g;
Result = Result > b ? Result : b;
break;
case 2: //加权平均值法
Result = ((int)(0.3 * r) + (int)(0.59 * g) + (int)(0.11 * b));
break;
}
newlbmp.SetPixel(x, y, Color.FromArgb(Result, Result, Result));
}
}
lbmp.UnlockBits();
newlbmp.UnlockBits();
return(newbmp);
}
