Using DCT coefficients flipping for information hiding in still images

The paper deals with information hiding in general and special focus is given to information content hiding in still images. A solution of information hiding of protected part of an image within the image itself is also presented. Three approaches are proposed - digital watermarking, DCT coefficients flipping and cryptography. The main focus of this paper is oriented to information hiding based on DCT coefficients flipping. In this case the information content protection is based on pixelisation and mosaic approach. Some experimental results are shown and advantages and drawbacks are also discussed.