'|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

'Author: Larry Nung

'Date: 2009/6/2

'File: 

'Memo: 

'|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

''' <summary>

''' 

''' </summary>

''' <remarks></remarks>

Public Class Form1

    '***************************************************************************

    'Author: Larry Nung

    'Date: 2009/6/2

    'Purpose: 

    'Memo: 

    '***************************************************************************

    ''' <summary>

    ''' Handles the Click event of the Button1 control.

    ''' </summary>

    ''' <param name="sender">The source of the event.</param>

    ''' <param name="e">The <see cref="System.EventArgs" /> instance containing the event data.</param>

    ''' <remarks></remarks>

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then

            Me.PictureBox1.Image = GetGrayBitmap(OpenFileDialog1.FileName)

        End If

    End Sub  '更多.net源码和教程，来自[乐博网 www.lob.cn]

    '***************************************************************************

    'Author: Larry Nung

    'Date: 2009/6/2

    'Purpose: 

    'Memo: 

    '***************************************************************************

    ''' <summary>

    ''' Gets the gray image.

    ''' </summary>

    ''' <param name="file">The file.</param>

    ''' <returns></returns>

    ''' <remarks></remarks>

    Private Function GetGrayBitmap(ByVal file As String) As Bitmap

        Dim bmp As Bitmap = New Bitmap(file)

        For x As Integer = 0 To bmp.Width - 1

            For y As Integer = 0 To bmp.Height - 1

                Dim color As Color = bmp.GetPixel(x, y)

                Dim gray As Integer = (CInt(color.R) + CInt(color.G) + CInt(color.B)) \ 3

                bmp.SetPixel(x, y, color.FromArgb(gray, gray, gray))

            Next

        Next

        Return bmp

    End Function

End Class

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    //|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

    //Author: Larry Nung

    //Date: 2009/6/2

    //File: 

    //Memo: 

    //|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

    /// <summary>

    /// 

    /// </summary>

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //***************************************************************************

        //Author: Larry Nung

        //Date: 2009/6/2

        //Purpose: 

        //Memo: 

        //***************************************************************************

        /// <summary>

        /// Handles the Click event of the button1 control.

        /// </summary>

        /// <param name="sender">The source of the event.</param>

        /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>

        private void button1_Click(object sender, EventArgs e)

        {

            if (openFileDialog1.ShowDialog() == DialogResult.OK)

            {

                pictureBox1.Image = GetGrayBitmap(openFileDialog1.FileName);

            }

        }  '更多.net源码和教程，来自[乐博网 www.lob.cn]

        //***************************************************************************

        //Author: Larry Nung

        //Date: 2009/6/2

        //Purpose: 

        //Memo: 

        //***************************************************************************

        /// <summary>

        /// Gets the gray bitmap.

        /// </summary>

        /// <param name="file">The file.</param>

        /// <returns></returns>

        private Bitmap GetGrayBitmap(string file)

        {

            Bitmap bmp = new Bitmap(file);

            for (int x=0; x < bmp.Width; x++)

            {

                for (int y=0; y < bmp.Height; y++)

                {

                    Color color = bmp.GetPixel(x, y);

                    int gray = (color.R + color.G + color.B) / 3;

                    bmp.SetPixel(x, y, Color.FromArgb(gray, gray, gray));

                }

            }

            return bmp;

        }

    }

}