Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices
 
Public Class Form5
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
 
        OpenFileDialog1.Filter = "JPG (*.JPG)|*.jpg|GIF (*.gif)|*.gif|Alle|*.*"
        OpenFileDialog1.ShowDialog()
        BildAnzeigeNeu.Image = Image.FromFile(OpenFileDialog1.FileName)
 
    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        PictureBox1.Image = BildAnzeigeNeu.Image
 
        PictureBox1.Refresh()
 
    End Sub
 
    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
 
        If IsNothing(BildAnzeigeNeu.Image) Then Exit Sub
 
        Dim Diff As Byte = Farbabweichung.Text
        Dim A As Byte = AktuelleFarbeA.Text
        Dim R As Byte = AktuelleFarbeR.Text
        Dim G As Byte = AktuelleFarbeG.Text
        Dim B As Byte = AktuelleFarbeB.Text
        Dim RN As Byte
        Dim GN As Byte
        Dim BN As Byte
        Dim z As Integer
 
        For z = Diff * -1 To Diff
 
            Dim bmp As Bitmap = New Bitmap(BildAnzeigeNeu.Image)
 
            Dim Graph As Graphics = Graphics.FromImage(bmp)
 
            RN = R + z
            GN = G + z
            BN = B + z
            If RN < 0 Then
                RN = 0
            End If
            If RN > 255 Then
                RN = 255
            End If
 
            If GN < 0 Then
                GN = 0
            End If
            If GN > 255 Then
                GN = 255
            End If
 
            If BN < 0 Then
                BN = 0
            End If
            If BN > 255 Then
                BN = 255
            End If
 
            Dim attr As New ImageAttributes
 
             Dim c As Color = Color.FromArgb(0, RN, GN, BN)
 
            ' Set the transparency color key based on the upper-left pixel 
            ' of the image.
            ' Uncomment the following line to make all black pixels transparent:
            '  attr.SetColorKey(bmp.GetPixel(0, 0), bmp.GetPixel(0, 0))
 
            ' Set the transparency color key based on a specified value.
            ' Uncomment the following line to make all red pixels transparent:
            attr.SetColorKey(c, c)
 
            ' Draw the image using the image attributes.
            PictureBox1.Image = Nothing
            Dim dstRect As New Rectangle(0, 0, bmp.Width, bmp.Height)
            e.Graphics.DrawImage(bmp, dstRect, 0, 0, bmp.Width, bmp.Height, _
              GraphicsUnit.Pixel, attr)
         Next
    End Sub
 
    Private Sub Form5_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        AktuelleFarbeA.Text = 255
        AktuelleFarbeR.Text = 220
        AktuelleFarbeG.Text = 241
        AktuelleFarbeB.Text = 236
        Farbabweichung.Text = 0
        'invert()
    End Sub
end class