Image steganalysis is the science of analyzing images in order to discover methods of discovering and detecting hidden messages and data within the images. Statistical digital signal processing is often used in order to detect data within images.
It is important to detect hidden messages within the images. On the steganography side, this is important in order to find methods in order to improve the algorithm implementing steganography. By exposing the flaws to the algorithm, the user can further improve the algorithm in order to make it more difficult to detect whether or not data is hidden in the images.
Steganalysis is also especially important in the security aspect, namely monitoring a user’s communication with the outside world. In the age of Internet, images are sent via email or by posting on websites. Detecting whether or not data is hidden in the images will allow the monitor to further analyze the suspicious images in order find what the hidden message is.