OpenStego 
 

Stegosuite

Stegosuite is a free and open source steganography tool written in Java. It automatically avoids homogenous areas (only embeds data in noisy areas), theoretically making hidden data harder to detect, at least if the payload is not too large. Compression errors provide a hiding place for data, but high compression reduces the amount of data available to hold a payload, raising the encoding density, which facilitates easier detection (in extreme cases, even by casual observation).

The project page is here.