public class FastEdgeDetectFilter : BaseFilter
{
   protected override void ApplyFilter()
   {
       // store the bitmap information first
       int width = this.DrawArea.Right;
       int height = this.DrawArea.Bottom
       int startX = this.DrawArea.Left;
       int startY = this.DrawArea.Right;

       // scan each column of the image
       for (int x = startX; x < width; x++)
       {
           // scan each row of the image
           for (int y = startY; y < height; y++)
           {
               if (x + 2 < width && y + 2 < height)
               {
                   Color offset = getPixel(x + 2, y + 2);
                   Color current = getPixel(x, y);

                   // apply the algorithm
                   byte red = (byte)(current.R + (128 - offset.R));
                   byte green = (byte)(current.G + (128 - offset.G));
                   byte blue = (byte)(current.B + (128 - offset.B));

                   Color newColor = Color.FromArgb(red, green, blue);
                   setPixel(x, y, newColor);
               }
           }
       }
   }
}

Imports IC.PhotoController.Filter
Imports System.Drawing
 
Public Class FastEdgeDetectFilter
    Inherits IC.PhotoController.Filter.BaseFilter
 
    Protected Overrides Sub ApplyFilter()
 
        Dim width As Integer = DrawArea.Width
        Dim height As Integer = DrawArea.Height
        Dim startX As Integer = DrawArea.Left
        Dim startY As Integer = DrawArea.Right
 
        Dim x As Integer
        Dim y As Integer
 
        For x = 0 To width
            For y = 0 To height
                If (x + 2 < width And y + 2 < height) Then
                    Dim offset As Color = getPixel(x + 2, y + 2)
                    Dim current As Color = getPixel(x, y)
 
                    Dim red As Byte
                    Dim blue As Byte
                    Dim green As Byte
 
                    red = IntToByte(current.R + (128 - offset.R))
                    green = IntToByte(current.G + (128 - offset.G))
                    blue = IntToByte(current.B + (128 - offset.B))
 
                    Dim newColor As Color = Color.FromArgb(red, green, blue)
                    setPixel(x, y, newColor)
                End If
            Next
        Next
    End Sub
End Class