how to decompress an image in wpf?

void compress(Image img,string path){
            EncoderParameter qualityParam =
                new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 60);
            ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
            EncoderParameters encoderParams = new EncoderParameters(1);
            encoderParams.Param[0] = qualityParam;
            
            img.Save("check1.jpg", jpegCodec, encoderParams);
        }
        private static ImageCodecInfo GetEncoderInfo(string mimeType)
        {
            // Get image codecs for all image formats 
            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
 
            // Find the correct image codec 
            for (int i = 0; i < codecs.Length; i++)
                if (codecs[i].MimeType == mimeType)
                    return codecs[i];
            return null;
        }