asp.net 圖片質量壓縮(不改變尺寸)

PRivate static ImageCodecInfo GetEncoderInfo(String mimeType) { int j; ImageCodecInfo[] encoders; encoders = ImageCodecInfo.GetImageEncoders(); for (j = 0; j < encoders.Length; ++j) { if (encoders[j].MimeType == mimeType) return encoders[j]; } return null; }

/// <summary> /// 圖片壓縮(降低質量以減小文件的大小) /// </summary> /// <param name="srcBitmap">傳入的Bitmap對象</param> /// <param name="destStream">壓縮后的Stream對象</param> /// <param name="level">壓縮等級，0到100，0 最差質量，100 最佳</param> public static void Compress(Bitmap srcBitmap, Stream destStream, long level) { ImageCodecInfo myImageCodecInfo; Encoder myEncoder; EncoderParameter myEncoderParameter; EncoderParameters myEncoderParameters;

// Get an ImageCodecInfo object that represents the JPEG codec. myImageCodecInfo = GetEncoderInfo("image/jpeg");

// Create an Encoder object based on the GUID

// for the Quality parameter category. myEncoder = Encoder.Quality;

// Create an EncoderParameters object. // An EncoderParameters object has an array of EncoderParameter // objects. In this case, there is only one

// EncoderParameter object in the array. myEncoderParameters = new EncoderParameters(1);

// Save the bitmap as a JPEG file with 給定的 quality level myEncoderParameter = new EncoderParameter(myEncoder, level); myEncoderParameters.Param[0] = myEncoderParameter; srcBitmap.Save(destStream, myImageCodecInfo, myEncoderParameters); }

/// <summary> /// 圖片壓縮(降低質量以減小文件的大小) /// </summary> /// <param name="srcBitMap">傳入的Bitmap對象</param> /// <param name="destFile">壓縮后的圖片保存路徑</param> /// <param name="level">壓縮等級，0到100，0 最差質量，100 最佳</param> public static void Compress(Bitmap srcBitMap, string destFile, long level) { Stream s = new FileStream(destFile, FileMode.Create); Compress(srcBitMap, s, level); s.Close(); }