I make a screenshot using Selenium, cut it off and want to save it with compression, but it doesn't happen (- what's the catch?

So checked the original:

screenshot2.Save(String.Format(@"C:\SeleniumScreenshots\" + fileName, ImageFormat.Jpeg));

And so I tried to squeeze:

 screenshot2.Save(String.Format(@"C:\SeleniumScreenshots\" + fileName, ImageFormat.Jpeg, new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 25L)));

And every time files of the same size

0