Library for further (lossless) Jpeg-compression

Question

I\'m looking for a library specialized at compressing Jpegs even further without changing the image. I\'ve found PackJpeg but it doesn\'t provide any source code and you\'re

Answer 1

In researching this same problem, I ran across JPEGmini, which is available as an online service. The claim:

JPEGmini is capable of reducing the file size of standard JPEG photos by up to 80% (5X), while the resulting photos are visually identical to the original photos.

I took the jpg/jpeg lossless image compression test A10 image down from 823KB to 171KB.