Image Comparison using C#

I am proud to present you our unique image comparison application in C#.Net. C# .Net provides a good support for processing on the image, and the purpose of this article is not to give you a lot of insight into the image processing, rather it is written to help you start your image processing career using C#.

Lets create a project and compare two images using this application. to do this follows the given steps:

Step 1: In Visual studio 2005. click on file menu -> New -> Project then the following dialogbox will appear.

Figure 1:

Step 2: Now drag and drop the following tools on the Form from toolbox.

Two LinkLable
One Button
Two OpenFileDialog
ProgressBar
PictureBox

Figure 2:

Step 3: Go to properties window and design the form as you want.

Figure 3:

Step 4: Double click on form and write the following line on the form_load.

private void Form1_Load(object sender, EventArgs e)
{
    progressBar1.Visible = false;
    pictureBox1.Visible = false;
}

Step 5: Add using System.IO; the namespace.

Step 6: Write the following line on the linkLabel1_LinkClicked event

private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
    openFileDialog1.FileName = "";
    openFileDialog1.Title = "Images"; 
    openFileDialog1.Filter = "All Images|*.jpg; *.bmp; *.png"; 
    openFileDialog1.ShowDialog(); 
    if (openFileDialog1.FileName.ToString() != "")
    {
        fname1 = openFileDialog1.FileName.ToString();
    }
}

Step 7: Write the following line on the linkLabel2_LinkClicked event

private void linkLabel2_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
    openFileDialog2.FileName = "";
    openFileDialog2.Title = "Images"; 
    openFileDialog2.Filter = "All Images|*.jpg; *.bmp; *.png"; 
    openFileDialog2.ShowDialog(); 
    if (openFileDialog2.FileName.ToString() != "")
    {
        fname2 = openFileDialog2.FileName.ToString();
    }
}

Step 8: Finally write the follwoing code in the button click event.

private void button1_Click(object sender, EventArgs e)
{
    progressBar1.Visible = true;
    string img1_ref, img2_ref;
    img1 = new Bitmap(fname1);
    img2 = new Bitmap(fname2);
    progressBar1.Maximum = img1.Width;
    if (img1.Width == img2.Width && img1.Height == img2.Height)
    {
        for (int i = 0; i < img1.Width; i++)
        {
            for (int j = 0; j < img1.Height; j++)
            {
                img1_ref = img1.GetPixel(i, j).ToString();
                img2_ref = img2.GetPixel(i, j).ToString();
                if (img1_ref != img2_ref)
                {
                    count2++;
                    flag = false;
                    break;
                }
                count1++;
            }
            progressBar1.Value++;
        }
        if (flag == false)
        MessageBox.Show("Sorry, Images are not same , " + count2 + " wrong pixels found");
        else
        MessageBox.Show(" Images are same , " + count1 + " same pixels found and " + count2 + " wrong pixels found");
    }
    else
    MessageBox.Show("can not compare this images");
    this.Dispose();
}

Step 9: Now debug the application. When you compare same images like as follows:

Img 1:

Img 2:

Then the following output will occur.

Figure 4:

Step 10: When you compare different images like as follows:

Img 3_Different:

Then the following output will occur.

Figure 5: