C# ile siyah beyaz resmin x,y, kordinatlarını çıkartıp yazdırma

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace sb
{

	public partial class MainForm : Form
	{
		static List<Point> koordinatlar = new List< Point >();
		public static List<Point> SiyahBeyazKoordinatAl( Bitmap bitmap)
		{
			unsafe
			{
				koordinatlar.Clear();
				BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);

				var bytesPerPixel = Image.GetPixelFormatSize(bitmap.PixelFormat) / 8;
				var heightInPixels = bitmapData.Height;
				var widthInBytes = bitmapData.Width * bytesPerPixel;
				var PtrFirstPixel = (byte*)bitmapData.Scan0;

				for (int y = 0; y < heightInPixels; y++)
				{
					byte* currentLine = PtrFirstPixel + (y * bitmapData.Stride);
					for (int x = 0; x < widthInBytes; x += bytesPerPixel)
					{
						int oldBlue = currentLine[x];
						int oldGreen = currentLine[x + 1];
						int oldRed = currentLine[x + 2];
						
						if (oldBlue==0 && oldGreen==0 && oldRed==0) {
							koordinatlar.Add(new Point(x/4, y));
						}
						
					}
				}
				bitmap.UnlockBits(bitmapData);
			}
			return koordinatlar;
		}
		
		
		public MainForm()
		{
	
			InitializeComponent();
	
		}
		void Button1Click(object sender, EventArgs e)
		{
			listBox1.DataSource = null;
			listBox1.DataSource = SiyahBeyazKoordinatAl(new Bitmap(pictureBox1.Image));

		}
		void Button2Click(object sender, EventArgs e)
		{
			if (openFileDialog1.ShowDialog()==DialogResult.OK) {
				pictureBox1.Image = new Bitmap(openFileDialog1.FileName);
			}

		}
	}
}