public void Flip(RotateFlipType flip)
        {
            this.ImageViewer.Flip(flip);

            if (addToHistory)
            {
                History h = new History("Flip");
                h.FunctionParameters.Add(flip);
                opHistory.Add(h);
            }
        }
        public void Rotate(RotateFlipType rotate)
        {
            this.ImageViewer.Rotate(rotate);

            if (addToHistory)
            {
                History h = new History("Rotate");
                h.FunctionParameters.Add(rotate);
                opHistory.Add(h);
            }
        }