#region 图片压缩，转换为JPG格式
        /// <summary>
        /// 获取指定mimeType的ImageCodecInfo
        /// </summary>
        private static ImageCodecInfo GetImageCodecInfo(string mimeType)
        {
            ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
            foreach(ImageCodecInfo ici in CodecInfo)
            {
                if(ici.MimeType == mimeType)
                    return ici;
            }
            return null;
        }


        /// <summary>
        ///  获取inputStream中的Bitmap对象
        /// </summary>
        public static Bitmap GetBitmapFromStream(Stream inputStream)
        {
            Bitmap bitmap = new Bitmap(inputStream);
            return bitmap;
        }

        /// <summary>
        /// 将Bitmap对象压缩为JPG图片类型
        /// </summary>
        /// <param name="bmp">源bitmap对象</param>
        /// <param name="saveFilePath">目标图片的存储地址</param>
        /// <param name="quality">压缩质量，越大照片越清晰，推荐80</param>
        public static void CompressAsJPG(Bitmap bmp, string saveFilePath, int quality)
        {
            EncoderParameter p = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
            ;
            EncoderParameters ps = new EncoderParameters(1);
            ps.Param[0] = p;
            bmp.Save(saveFilePath, GetImageCodecInfo("image/jpeg"), ps);
            bmp.Dispose();
        }

        /// <summary>
        /// 将inputStream中的对象压缩为JPG图片类型
        /// </summary>
        /// <param name="inputStream">源Stream对象</param>
        /// <param name="saveFilePath">目标图片的存储地址</param>
        /// <param name="quality">压缩质量，越大照片越清晰，推荐80</param>
        public static void CompressAsJPG(Stream inputStream, string saveFilePath, int quality)
        {
            Bitmap bmp = GetBitmapFromStream(inputStream);
            CompressAsJPG(bmp, saveFilePath, quality);
        }
        #endregion