I am working with GDI+, the image I am working with is a 1bbp image. What i would like to do is draw a rectangle on the image and everything under that rectangle will be inverted (white pixels will become black and black pixels become white).

All of the sample code I have seen is for 8 bit RGB color scale images, and I don't think the techniques they use will work for me.

Here is the code I have so far. This is the parent control, one of the Epl2.IDrawableCommand's will be the command that does the inverting.

protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);
    if (Label != null)
    {
        using (Bitmap drawnLabel = new Bitmap((int)((float)Label.LabelHeight * _ImageScaleFactor), (int)((float)Label.LableLength *(int) _ImageScaleFactor), System.Drawing.Imaging.PixelFormat.Format1bppIndexed))
        {
            using (Graphics drawBuffer = Graphics.FromImage(drawnLabel))
            {
                drawBuffer.ScaleTransform(_ImageScaleFactor, _ImageScaleFactor);
                foreach (Epl2.IDrawableCommand cmd in Label.Collection)
                {
                    cmd.Paint(drawBuffer);
                }
                drawBuffer.ResetTransform();
            }
            drawnLabel.RotateFlip(Rotation);
            pbLabelDrawArea.Size = drawnLabel.Size;
            using (Graphics drawArea = pbLabelDrawArea.CreateGraphics())
            {
                drawArea.Clear(Color.White);
                drawArea.DrawImage(drawnLabel, new Point(0, 0));
            }
        }
    }
}

What should I put in the Paint(Graphic g) for this command?