using System;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;

namespace CobaLoadGambar
{
    public partial class Form1 : Form
    {
        private System.Drawing.Bitmap m_Bitmap;
        //private double Zoom = 1.0;

        public Form1()
        {
            InitializeComponent();
            m_Bitmap = new Bitmap(2, 2);
        }
        protected override void  OnPaint(PaintEventArgs e)
        {
 	        //Graphics g = e.Graphics;
            //g.DrawImage(m_Bitmap, new Rectangle(this.AutoScrollPosition.X, this.AutoScrollPosition.Y, (int)(m_Bitmap.Width * Zoom), (int)(m_Bitmap.Height * Zoom)));
}
        }
        private void loadimage_Click(object sender, EventArgs e) {
            OpenFileDialog openFileDialog = new OpenFileDialog();

            openFileDialog.InitialDirectory = "E:\\";
            openFileDialog.Filter = "Bitmap files (*.bmp)|*.bmp|Jpeg files(*.jpg)|*.jpg|All valid files (*.bmp/*.jpg)|*.bmp/*.jpg";
            openFileDialog.FilterIndex = 2;
            openFileDialog.RestoreDirectory = true;

            if (DialogResult.OK == openFileDialog.ShowDialog())
            {
                m_Bitmap = (Bitmap)Bitmap.FromFile(openFileDialog.FileName, false);
                //utk ganti ukuran formnya sesuai gambar
                //this.AutoScroll = true;
                //this.AutoScrollMinSize = new Size((int)(m_Bitmap.Width * Zoom),(int)(m_Bitmap.Height * Zoom));
                //this.Invalidate();
                pictureBox1.Image = m_Bitmap;
            }
        }
    private void Form1_Load(object sender, EventArgs e){}
    private void button1_Click(object sender, EventArgs e){
        Bitmap b = (Bitmap)pictureBox1.Image;
        BitmapData bmData = b.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);

        int stride = bmData.Stride;
        System.IntPtr Scan0 = bmData.Scan0;

        unsafe
        {
           byte* p = (byte*)(void*)Scan0;
           int nOffset = stride - b.Width * 3;
           byte red, green, blue;

           for (int y = 0; y < b.Height; ++y)
            {
             for (int x = 0; x < b.Widht; ++x)
            {
            blue = p[0];
            green = p[1];
            red = p[2];

            p[0] = p[1] = p[2] = (byte)(.299*red + .587*green +.114*blue);
            p += 3;
            }
             p += nOffset;
            }
        }
        b.UnlockBits(bmData);
        pictureBox2.Image = b;
        }
    }
}