代码如下：

using System;using System.Collections;using System.Configuration;using System.Data;using System.Linq;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Xml.Linq;using System.Drawing;using System.Drawing.Imaging;/* 何问起 hovertree.com */namespace WebApplication2{    public partial class _Default : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            Bitmap b = new Bitmap(Server.MapPath("01.jpg"));            for (int x = 0; x < b.Width; x++)            {                for (int y = 0; y < b.Height; y++)                {                    Color pixel = b.GetPixel(x, y);                    int val = (pixel.R + pixel.G + pixel.B) / 3;                    b.SetPixel(x, y, Color.FromArgb(val, val, val));                }            }            b.Save(Server.MapPath("1.jpg"));        }    }}

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