Word截图PNG，并压缩图片大小

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 = ; 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();
            }
        }