Asp.net(C#)-彩色图片转化为黑白

    ///

    /// 彩色图片转化为黑白
    ///

    ///
    ///
    public static Bitmap ConvertToGrayscale(Bitmap bitmap)
    {
        Bitmap bm = new Bitmap(bitmap.Width, bitmap.Height);
        for (int y = 0; y < bm.Height; y++)
        {
            for (int x = 0; x < bm.Width; x++)
            {
                Color c = bitmap.GetPixel(x, y);
                int rgb = (int)(c.R * 0.3 + c.G * 0.59 + c.B * 0.11);
                bm.SetPixel(x, y, Color.FromArgb(rgb, rgb, rgb));
            }
        }
        return bm;
    }