有開關PCX檔案 放大縮小n倍 還有旋轉圖片 Contrast Stretching即時控制 畫直方圖 Otsu二值化 bit plane gray code 浮水印 Histogram equalitation-PCX files are switch n times zoom Contrast Stretching also rotate the picture painted real-time control histogram Otsu Binarization bit plane