This thesis deals with digital steganography and steganalysis. It explains the significance of both disciplines and gives a brief overview of the history in the given fields. The paper separates existing steganographic and steganalytic methods and describes the attributes of various branches of steganography. With respect to the chosen field of steganography (the image steganography), the paper narrows down the set of suitable steganographic and steganalytic methods, whose features are then described in detail. The results of the thesis inlcude experiments that verify the features of chosen steganographic methods and evaluation of steganalytic methods and their success in detection of steganography.