pictureBox image load time link to progressbar

I've created a simple image viewer and want to link my load time of the image that is being opened in a pictureBox to a progress bar. Here is what I have:
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;
using System.Threading;
namespace ImageViewer
{
  public partial class Form1 : Form
  {
  ProgressBar pBar = new ProgressBar();
  Label pLabel = new Label();
  BackgroundWorker backgroundWorker1 = new BackgroundWorker();
  ProgressBar progressBar1 = new ProgressBar();
  public Form1()
  {
  InitializeComponent();
  this.WindowState = FormWindowState.Maximized;
  CreateProgressBar();
  CreateLabel();
  Shown += new EventHandler(Form1_Shown);
  backgroundWorker1.WorkerReportsProgress = true;
  backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
  backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
  }
  private void CreateLabel()
  {
  pLabel.Location = new System.Drawing.Point(500, 16);
  pLabel.Text = "Progress";
  Controls.Add(pLabel);
  }
  private void CreateProgressBar()
  {
  pBar.Location = new System.Drawing.Point(550, 13);
  pBar.Name = "progressBar1";
  pBar.Text = "Progress";
  pBar.Width = 300;
  pBar.Height = 20;
  pBar.Minimum = 0;
  pBar.Maximum = 100;
  Controls.Add(pBar);
  }

  private void folderPath_Click(object sender, EventArgs e)
  {
  OpenFileDialog open = new OpenFileDialog();
  open.FileName = "";
  open.Filter = "Image Files(*.tif; *.jpg; *.jpeg; *.gif; *.bmp)|*.tif; *.jpg; *.jpeg; *.gif; *.bmp";
  open.InitialDirectory = @"g:\All Scanned Jobs\";
  if (open.ShowDialog() != DialogResult.Cancel)
  {
  // display image in picture box
  pictureBox1.Image = new Bitmap(open.FileName);
  pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
  pictureBox1.WaitOnLoad = false;
  pictureBox1.LoadAsync(open.FileName);
  }
  }

  void Form1_Shown(object sender, EventArgs e)
  {
  backgroundWorker1.RunWorkerAsync();
  }
  void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
  {
  var num = 0; // I NEED TO STORE THE IMAGE LOAD TIME HERE I THINK
  int time = Convert.ToInt32(num);
  for (int i = time; i <= 100; i++)
  {
  backgroundWorker1.ReportProgress(i);
  }
  }
  void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
  {
  pBar.Value = e.ProgressPercentage;
  }
  private void button1_Click(object sender, EventArgs e)
  {
  pictureBox1.Image.RotateFlip(RotateFlipType.Rotate180FlipNone);
  pictureBox1.Refresh();
  }
  private void button2_Click(object sender, EventArgs e)
  {
  pictureBox1.Image.RotateFlip(RotateFlipType.Rotate90FlipNone);
  pictureBox1.Refresh();
  }
  }
}