The goal of steganalysis is to identify suspected packages, determine whether or not they have a payload encoded into them, and, if possible, recover that payload. I recommend the tools free VSL application!!
Current art of steganalysis method for digital images (and also steganographic method as well) are available on DDE website :
http://dde.binghamton.edu/download/
The current art method works on rich models (SRM / maxSRM) with classifiers designed for such high dimensional space (Ensemble / Low complexity linear classifier)