哪位高人给我看看我这段生成缩微图的代码是不是有问题，导致应用程序池资源耗尽？？


/// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="originalImagePath">源图路径（物理路径）</param>
        /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
        /// <param name="width">缩略图宽度</param>
        /// <param name="height">缩略图高度</param>
        /// <param name="mode">生成缩略图的方式:HW W H Cut </param>    
        /// <param name="interpolMode">插值算法</param>
        /// <param name="smoothingMode">平滑处理</param>
        public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode, InterpolationMode interpolMode, SmoothingMode smoothingMode)
        {
            Image originalImage = Image.FromFile(originalImagePath);            int towidth = width;
            int toheight = height;            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）                
                    break;
                case "W"://指定宽，高按比例                    
                    toheight = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）                
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }            //新建一个bmp图片
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight, PixelFormat.Format24bppRgb);            //新建一个画板
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);            //设置高质量插值法
            g.InterpolationMode = interpolMode;            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = smoothingMode;            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);            try
            {
                //以jpg格式保存缩略图
                //bitmap.Save(thumbnailPath);直接保存忒太了
                EncoderParameters parameters = new EncoderParameters(1);
                parameters.Param[0] = new EncoderParameter(Encoder.Quality, ((long)80));
                bitmap.Save(thumbnailPath, ImageHelper.GetCodecInfo("image/" + ImageHelper.GetFormat(thumbnailPath).ToString().ToLower()), parameters);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }
        }        /// <summary>
        /// 得到图片格式
        /// </summary>
        /// <param name="name">文件名称</param>
        /// <returns></returns>
        public static ImageFormat GetFormat(string name)
        {
            string ext = name.Substring(name.LastIndexOf(".") + 1);
            switch (ext.ToLower())
            {
                case "jpg":
                case "jpeg":
                    return ImageFormat.Jpeg;
                case "bmp":
                    return ImageFormat.Bmp;
                case "png":
                    return ImageFormat.Png;
                case "gif":
                    return ImageFormat.Gif;
                default:
                    return ImageFormat.Jpeg;
            }
        }        /// <summary>
        /// 获取图像编码解码器的所有相关信息
        /// </summary>
        /// <param name="mimeType">包含编码解码器的多用途网际邮件扩充协议 (MIME) 类型的字符串</param>
        /// <returns>返回图像编码解码器的所有相关信息</returns>
        public static ImageCodecInfo GetCodecInfo(string mimeType)
        {
            ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
            foreach (ImageCodecInfo ici in CodecInfo)
            {
                if (ici.MimeType == mimeType) return ici;
            }
            return null;
        }
我上传30来张1M的图片，都调用这个生成缩微图 每个缩微图就50来k，就无法访问该页面了 重启应用程序池就正常了  郁闷~
是不是程序有问题喃？