internal static extern bool FillBackground(FIBITMAP dib, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options);
internal static extern FIBITMAP EnlargeCanvas(FIBITMAP dib, int left, int top, int right, int bottom, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options);
internal static extern FIBITMAP AllocateExT(FREE_IMAGE_TYPE type, int width, int height, int bpp, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options, RGBQUAD[] palette, uint red_mask, uint green_mask, uint blue_mask);
private static extern bool FillBackgroundWindows(FIBITMAP dib, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options);
private static extern FIBITMAP EnlargeCanvasWindows(FIBITMAP dib, int left, int top, int right, int bottom, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options);
private static extern FIBITMAP AllocateExTWindows(FREE_IMAGE_TYPE type, int width, int height, int bpp, IntPtr color, FREE_IMAGE_COLOR_OPTIONS options, RGBQUAD[] palette, uint red_mask, uint green_mask, uint blue_mask);