Compare two images to find differences using Visual Basic Image Processing code samples

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Compare two images to find differences in each image using Visual Basic .NET This example shows how to compare two images to find differences in VB .NET. When you select two images to compare the program executes the following code. It loads the two image files into Bitmaps. It finds the smaller of the Bitmaps' widths and heights, and makes a new Bitmap of that size. Next the program loops over the pixels in the smaller area, comparing the the images' pixels. If two corresponding pixels are equal, the program colors the result pixel white. If the two pixels are unequal, the program makes the result pixel red. When it has examined all of the pixels, the program displays the result image. The result image highlights differences between the two input images no matter how small the differences are. If a pixel in one image has RGB values 50, 150, 200 and the corresponding pixel in the other image has RGB values 51, 150, 200, the result shows the difference plainly even though you won't be able to tell the difference with your eyes.


First	Second Used Edge Finding	Differance in two images

Imports System.Math
               
Public Function Compare2Images(ByVal firstImage As Image, ByVal secondImage As Image) As Image

' Load the images.
Dim bm1 As Bitmap = firstImage
Dim bm2 As Bitmap = secondImage

'Make a difference image. 
Dim width As Integer = Math.Min(bm1.Width, bm2.Width)
Dim height As Integer = Math.Min(bm1.Height, bm2.Height)
Dim bm3 As New Bitmap(width, height)

'Create the difference image.
Dim are_identical As Boolean = True

Dim eq_color As Color = Color.White
Dim ne_color As Color = Color.Red

For x As Integer = 0 To width - 1
    For y As Integer = 0 To height - 1
        If bm1.GetPixel(x, y).Equals(bm2.GetPixel(x, y)) Then
           bm3.SetPixel(x, y, eq_color)
        Else
           bm3.SetPixel(x, y, ne_color)
           are_identical = False
        End If
    Next y
Next x

'Display the result. 
working_Image = bm3
Return working_Image

If (bm1.Width <> bm2.Width) OrElse (bm1.Height <> bm2.Height) Then
    are_identical = False
        
If are_identical Then
   MessageBox.Show("The images are identical")
   return true
Else : MessageBox.Show("The images are different")
   return False
End If

bm1.Dispose()
bm2.Dispose()

End Function

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Visual basic Code Sample Find the Difference between two images