Bitmap bmp = (Bitmap)Image.FromFile("abc.jpg");
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici = null;
foreach (ImageCodecInfo codec in codecs)
{
if (codec.MimeType == "image/jpeg")
ici = codec;
}
EncoderParameters ep = new EncoderParameters();
ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 50);//压缩率为50
bmp.Save(@"C:\abc.jpg", ici, ep);
