PERFORMANCE ANALYSIS OF A 2-D MULTIPULSE AMPLITUDE-MODULATION SCHEME FOR DATA HIDING AND WATERMARKING OF STILL IMAGES

In this paper a watermarking scheme for copyright protection of still images is modeled and analyzed. In this scheme a signal following a ke y-dependent two-directional multipulse modulation is added to the imag e for ownership enforcement purposes. The mains contribution of this p aper is the introduction of an analytical point of view to the estimat ion of performance measurements, two topics are covered ire the analys is: the ownership verification process, also called watermark detectio n Best, and the data-hiding process. In the first case, bounds and app roximations to the receiver operating characteristic are derived. Thes e results can be used to determine the threshold associated to a requi red probability of false alarm and the corresponding probability of de tection. The data-hiding process is modeled as a communications system and approximations for the bit error rate are derived. Finally, analy tical expressions are contrasted with experimental results.