static void Main(string[] args)        {            var iso = new ImageSaveOptions(SaveFormat.Png);            iso.PrettyFormat = true;            iso.UseHighQualityRendering = true;            iso.ImageColorMode=ImageColorMode.None;            //不能使用这个代码，因为会造成图片快速增大            //iso.UseAntiAliasing = true;            var doc = new Document(@"c:/doc/母亲的心.doc");            for (int i = 0; i < doc.PageCount; i++)            {                iso.PageIndex = i;                Stream stream = new MemoryStream();                doc.Save(stream, iso);                Bitmap image = new Bitmap(stream);                image.MakeTransparent(Color.White);                image.Save("C:/test" + i + ".png",ImageFormat.Png);                image.Dispose();                stream.Dispose();            }        }