Intel has a C/C++ JPEG library that works with Visual C++ under Win32. It would appear that their motivation is to distribute code that is optimized for the MMX extensions in their processor. License agreement has a few points that should be examined, but essentially it appears to be free. Please correct me if I’m wrong.

One reviewer of this site had this to say: I tried out the IJL library. It was slower than the Independent JPEG Group code. I was using IJL 1.5.

Vlandimire says: I use this library, v. 1.51 works very well.

http://developer.intel.com/software/products/perflib/ijl/index.htm