The past few years have seen an increasing interest in using images as cover media for steganographic communication. There have been a multitude of public-domain tools available for image-based steganography. Given this fact, detection of covert communications that utilize images has become an important issue. There have been several techniques for detecting stegoimages developed in the past few years. In this chapter, we review some fundamental notions related to steganography using image media, including security and capacity. We also describe in detail two steganalysis techniques that are representative of the different approaches that have been taken.