Question

I have very large images (jpg) and i want to write a csharp program to loop through the files and reduce the size of each image by 75%.

I tried this:

Image thumbNail = image.GetThumbnailImage(800, 600, null, new IntPtr()); 

but the file size is still very large.

Is there anyway to create thumbnails and have the filesize be much smaller?

Answer 1

private void CompressAndSaveImage(Image img, string fileName,          long quality) {     EncoderParameters parameters = new EncoderParameters(1);     parameters.Param[0] = new EncoderParameter(Encoder.Quality, quality);     img.Save(fileName, GetCodecInfo('image/jpeg'), parameters); }  private static ImageCodecInfo GetCodecInfo(string mimeType) {     foreach (ImageCodecInfo encoder in ImageCodecInfo.GetImageEncoders())         if (encoder.MimeType == mimeType)             return encoder;     throw new ArgumentOutOfRangeException(         string.Format(''{0}' not supported', mimeType)); } 

Usage:

Image myImg = Image.FromFile(@'C:\Test.jpg'); CompressAndSaveImage(myImg, @'C:\Test2.jpg', 10); 

That will compress Test.jpg with a quality of 10 and save it as Test2.jpg.

EDIT: Might be better as an extension method:

private static void SaveCompressed(this Image img, string fileName,          long quality) {     EncoderParameters parameters = new EncoderParameters(1);     parameters.Param[0] = new EncoderParameter(Encoder.Quality, quality);     img.Save(fileName, GetCodecInfo('image/jpeg'), parameters); } 

Usage:

Image myImg = Image.FromFile(@'C:\Test.jpg'); myImg.SaveCompressed(@'C:\Test2.jpg', 10);