CSharp 彩色图像转为灰度图像

using  System;
using  System.Collections;
using  System.Drawing;
using  System.Drawing.Imaging;

public   class  MyClass
... {
    public static void Main()
    ...{
        System.Drawing.Bitmap bm = new System.Drawing.Bitmap("F:/1寸.jpg");    
        System.Drawing.Imaging.ImageAttributes ia = new  System.Drawing.Imaging.ImageAttributes();
        float[][] grayMatrix = new float[][]...{
                                                new float[]...{0.299f,  0.299f,  0.299f,  0, 0},
                                                new float[]...{0.587f, 0.587f, 0.587f, 0, 0},
                                                new float[]...{0.114f, 0.114f, 0.114f, 0, 0},
                                                new float[]...{0, 0, 0, 1, 0},
                                                new float[]...{0, 0, 0, 0, 1}
                                            };
                                            
                                            
        ColorMatrix cm = new ColorMatrix(grayMatrix);

        ia.SetColorMatrix(cm);
        
        Bitmap Target = new Bitmap(bm.Width,bm.Height);
        
        WL("开始转换!");
        
        using (Graphics grap = Graphics.FromImage(Target)) ...{
            grap.DrawImage(bm, new Rectangle(0, 0, bm.Width, bm.Height),
                0, 0, bm.Width, bm.Height,
                GraphicsUnit.Pixel, ia);
        }
        
        WL("装换完毕!");
        Target.Save("F:/黑白一寸.jpg",ImageFormat.Jpeg);
        RL();
    }
    
    Helper methods#region Helper methods

    private static void WL(object text, params object[] args)
    ...{
        Console.WriteLine(text.ToString(), args);    
    }
    
    private static void RL()
    ...{
        Console.ReadLine();    
    }
    
    private static void Break() 
    ...{
        System.Diagnostics.Debugger.Break();
    }

    #endregion
}