c#的bitmap轉換為JPG圖片(轉)

public static ImageCodecInfo GetEncoder(ImageFormat format)
{
    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
    foreach (ImageCodecInfo codec in codecs)
    {
        if (codec.FormatID == format.Guid)
            return codec;
    }
    return null;
}
Bitmap im = 這里是原圖片
//轉成jpg
var eps = new EncoderParameters(1);
var ep = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 85L);
eps.Param[0] = ep;
var jpsEncodeer = GetEncoder(ImageFormat.Jpeg);
//保存圖片
imgurl = @"/Content/Upload/" + guid + extension;
im.Save(path + imgurl,jpsEncodeer,eps);
//釋放資源
im.Dispose();
ep.Dispose();
eps.Dispose();