The Below code is to convert a color image to gray scale image
Public Shared Function MakeGrayscale(ByVal original As Bitmap) As Bitmap
'make an empty bitmap the same size as original
Dim newBitmap As New Bitmap(original.Width, original.Height)
For i As Integer = 0 To original.Width - 1
For j As Integer = 0 To original.Height - 1
'get the pixel from the original image
Dim originalColor As System.Drawing.Color = original.GetPixel(i, j)
'create the grayscale version of the pixel
Dim grayScale As Integer = CInt(Math.Truncate((originalColor.R * 0.3) + (originalColor.G * 0.59) + (originalColor.B * 0.11)))
'create the color object
Dim newColor As System.Drawing.Color = System.Drawing.Color.FromArgb(grayScale, grayScale, grayScale)
'set the new image's pixel to the grayscale version
newBitmap.SetPixel(i, j, newColor)
Next
Next
Return newBitmap
End Function
