Public Sub markiere()
        Dim prozent_ As Integer = Convert.ToInt32(Mid(zoomfaktor_box.Text, 1, _
          zoomfaktor_box.Text.Length - 1))
        If korx > mainpic.Image.Width Or korx2 > mainpic.Image.Width Then Exit Sub
        If kory > mainpic.Image.Height Or kory2 > mainpic.Image.Height _
          Then Exit Sub
        korx = korx + hbar.Value : korx2 = korx2 + hbar.Value
        kory = kory + vbar.Value : kory2 = kory2 + vbar.Value
        korx = korx / prozent_ * 100 : kory = kory / prozent_ * 100
        korx2 = korx2 / prozent_ * 100 : kory2 = kory2 / prozent_ * 100
        Dim bearbeitung As Bitmap
        If Not bild.PixelFormat = Imaging.PixelFormat.Format1bppIndexed Then
            bearbeitung = bild
        Else
            bearbeitung = New Bitmap(bild.Width, bild.Height, _
              System.Drawing.Imaging.PixelFormat.Format24bppRgb)
            Dim gra As Graphics = Graphics.FromImage(bearbeitung)
            gra.DrawImage(bild, 0, 0, bild.Width, bild.Height)
            gra.Save()
        End If
        Dim i, j As Integer, farbe As Color
        For i = korx To korx2
            For j = kory To kory2
                farbe = bearbeitung.GetPixel(i, j)
                If farbe.R <= 255 And farbe.R > 210 And _
                   farbe.G <= 255 And farbe.G > 210 And _
                   farbe.B <= 255 And farbe.B > 210 Then
                    bearbeitung.SetPixel(i, j, farbe_bt.BackColor)
                End If
            Next
        Next
        bild = bearbeitung
        Dim event_ As New System.Windows.Forms.KeyEventArgs(Keys.Enter)
        zoomfaktor_box_KeyUp(Nothing, event_)
    End Sub

    Private Sub sides_up_ValueChanged(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles sides_up.ValueChanged
        If sides_up.Enabled = False Then Exit Sub
        bild.SelectActiveFrame(System.Drawing.Imaging.FrameDimension.Page, _
          sides_up.Value - 1)
        With mainpic
            .Image = bild
            .Width = bild.Width
            .Height = bild.Height
            .Visible = True
        End With
        zoomed = bild : zoomfaktor_box.Text = "100%" : einpass()
    End Sub