Real data performance evaluation of CAISS watermarking scheme

Abstract

In this paper we present real data bit error rate (BER) performance evaluation of the recently proposed correlation-and-bit-aware improved spread spectrum (CAISS) watermarking scheme (Valizadeh and Wang, IEEE Trans Inf Forensics Secur 6(2):267–282, 2011). Our tests were performed in discrete cosine transform (DCT) domain. The results show significant improvement as compared with traditional spread spectrum technique. Tests performed under medium JPEG compression and fixed peak signal-to-noise ratio (PSNR) indicate that appropriate choice of CAISS parameters allows for over a three orders of magnitude smaller BER compared to spread spectrum technique without side information about correlation. CAISS also significantly outperforms traditional spread spectrum when watermarked images are subjected to additive Gaussian noise or downscaled before watermark decoding. We also compared CAISS with the improved spread spectrum (ISS) scheme and found that CAISS can perform significantly better than ISS (in terms of BER) after medium JPEG compression but gives almost the same results in presence of additive Gaussian noise and image scaling.