form1.cs

its a gray scle file

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace GrayScale
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.PictureBox pb_color;
		private System.Windows.Forms.Button btn_convert;
		private System.Windows.Forms.Button btn_load;
		private System.Windows.Forms.Button btn_save;
		private System.Windows.Forms.PictureBox pb_grayscale;
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.pb_color = new System.Windows.Forms.PictureBox();
			this.pb_grayscale = new System.Windows.Forms.PictureBox();
			this.btn_convert = new System.Windows.Forms.Button();
			this.btn_load = new System.Windows.Forms.Button();
			this.btn_save = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// pb_color
			// 
			this.pb_color.Location = new System.Drawing.Point(0, 32);
			this.pb_color.Name = "pb_color";
			this.pb_color.Size = new System.Drawing.Size(232, 232);
			this.pb_color.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
			this.pb_color.TabIndex = 0;
			this.pb_color.TabStop = false;
			// 
			// pb_grayscale
			// 
			this.pb_grayscale.Location = new System.Drawing.Point(312, 32);
			this.pb_grayscale.Name = "pb_grayscale";
			this.pb_grayscale.Size = new System.Drawing.Size(248, 232);
			this.pb_grayscale.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
			this.pb_grayscale.TabIndex = 1;
			this.pb_grayscale.TabStop = false;
			// 
			// btn_convert
			// 
			this.btn_convert.ForeColor = System.Drawing.Color.Black;
			this.btn_convert.Location = new System.Drawing.Point(232, 88);
			this.btn_convert.Name = "btn_convert";
			this.btn_convert.Size = new System.Drawing.Size(75, 56);
			this.btn_convert.TabIndex = 2;
			this.btn_convert.Text = "Convert";
			this.btn_convert.Click += new System.EventHandler(this.btn_convert_Click);
			// 
			// btn_load
			// 
			this.btn_load.Location = new System.Drawing.Point(0, 0);
			this.btn_load.Name = "btn_load";
			this.btn_load.Size = new System.Drawing.Size(232, 23);
			this.btn_load.TabIndex = 3;
			this.btn_load.Text = "Load Image";
			this.btn_load.Click += new System.EventHandler(this.btn_load_Click);
			// 
			// btn_save
			// 
			this.btn_save.Location = new System.Drawing.Point(312, 0);
			this.btn_save.Name = "btn_save";
			this.btn_save.Size = new System.Drawing.Size(248, 23);
			this.btn_save.TabIndex = 4;
			this.btn_save.Text = "Save Image";
			this.btn_save.Click += new System.EventHandler(this.btn_save_Click);
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(560, 266);
			this.Controls.Add(this.btn_save);
			this.Controls.Add(this.btn_load);
			this.Controls.Add(this.btn_convert);
			this.Controls.Add(this.pb_grayscale);
			this.Controls.Add(this.pb_color);
			this.Name = "Form1";
			this.Text = "Form1";
			this.Load += new System.EventHandler(this.Form1_Load);
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void btn_load_Click(object sender, System.EventArgs e)
		{
			OpenFileDialog open = new OpenFileDialog();
			open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp";
			if (open.ShowDialog()==DialogResult.OK)
			{
				pb_color.Image = new Bitmap(open.FileName);
				btn_convert.Enabled=true;
			}
		}

		private void Form1_Load(object sender, System.EventArgs e)
		{
			btn_convert.Enabled=false;
			btn_save.Enabled=false;
		}

		private void btn_convert_Click(object sender, System.EventArgs e)
		{
			Bitmap grays = (Bitmap)pb_color.Image;
			int width = grays.Size.Width;
			int height = grays.Size.Height;

			for (int j=0; j<height; j++)
			{
				for (int i=0; i<width; i++)
				{
					Color col;
					col = grays.GetPixel(i, j);
					
					grays.SetPixel(i,j,Color.FromArgb((col.R+col.G+col.B)/3,(col.R+col.G+col.B)/3,(col.R+col.G+col.B)/3 ));
				}
			}

			pb_grayscale.Image = grays;
			btn_save.Enabled=true;
		}

		private void btn_save_Click(object sender, System.EventArgs e)
		{
			Bitmap b = (Bitmap)pb_grayscale.Image;
			SaveFileDialog save = new SaveFileDialog();
			save.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp";
			if (save.ShowDialog()==DialogResult.OK)
			{
				b.Save(save.FileName);
			}

		}
	}
}