Public Class Form3
    Private Sub BildanzeigeNeu_MouseClick(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles BildanzeigeNeu.MouseClick
        BildanzeigeNeu.Image = aSetTransparent(BildanzeigeNeu.Image)
    End Sub
 
    Private Sub BildanzeigeNeu_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles BildanzeigeNeu.MouseMove
        Me.XMouse.Text = e.X
        Me.YMouse.Text = e.Y
 
        If Me.XMouse.Text > BildanzeigeNeu.Width Or Me.YMouse.Text > _
          BildanzeigeNeu.Height Then Exit Sub
        If IsNothing(BildanzeigeNeu.Image) Then Exit Sub
 
        Dim myBitmap As New Bitmap(BildanzeigeNeu.Image)
        On Error Resume Next
        Dim pixelColor As Color = myBitmap.GetPixel(Val(Me.XMouse.Text), Val( _
          Me.YMouse.Text))
 
        AktuelleFarbeA.Text = pixelColor.A
        AktuelleFarbeR.Text = pixelColor.R
        AktuelleFarbeG.Text = pixelColor.G
        AktuelleFarbeB.Text = pixelColor.B
 
        Call BildanzeigeNeu.Refresh()
 
    End Sub
 
    Private Sub BildanzeigeNeu_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles BildanzeigeNeu.Paint
 
        ' Fadenkreuz zeichnen
        Dim fk As Graphics = e.Graphics
 
        Dim Ypoints As Point() = {New Point(0, Val(YMouse.Text)), New Point( _
          Me.BildanzeigeNeu.Width, Val(Me.YMouse.Text))}
        fk.DrawLines(Pens.Black, Ypoints)
 
        Dim Xpoints As Point() = {New Point(Val(XMouse.Text), 0), New Point(Val( _
          Me.XMouse.Text), Me.BildanzeigeNeu.Height)}
        fk.DrawLines(Pens.Black, Xpoints)
 
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        OpenFileDialog1.Filter = "JPG|*.jpg|Bitmap|*.bmp"
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            BildanzeigeNeu.Image = Image.FromFile(OpenFileDialog1.FileName)
 
        End If
 
    End Sub
 
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button3.Click
        BildanzeigeNeu.Image = SetTransparent(BildanzeigeNeu.Image)
    End Sub
 
    Private Function SetTransparent(ByVal vectorImage As Bitmap) As Bitmap
        Dim Diff As Integer = Farbabweichung.Text
        Dim A As Integer = AktuelleFarbeA.Text
        Dim R As Integer = AktuelleFarbeR.Text
        Dim G As Integer = AktuelleFarbeG.Text
        Dim B As Integer = AktuelleFarbeB.Text
        Dim RN As Integer
        Dim GN As Integer
        Dim BN As Integer
        Dim z As Integer
 
        For z = Diff * -1 To Diff
            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
            'MsgBox(z & "  RN " & RN & "  GN " & GN & "  BN " & BN)
            vectorImage.MakeTransparent(Color.FromArgb(A, RN, GN, BN))
        Next
        Return vectorImage
    End Function
 
End Class