On Some Properties of a Digital Watermarking Based on Complete Complementary Codes

In spread spectrum communication systems, it is required to use the spread sequences that have good correlation properties. Complete complementary code is a set of spread sequences, and has ideal auto- and cross-correlation properties. Some previous works have shown that it can be applied into wireless communication systems like approximately synchronized CDMA systems. The authors have proposed a digital watermarking scheme based on complete complementary codes and its extension to steganography. It has been shown that the proposed method has superiority to the watermarking scheme based on other spread spectrum sequences such as m-sequences and Gold sequences. In this paper, some other properties of the proposed method are shown through some numerical experiments using still color images. Discussions on the effects of collusion attacks and the extension to a blind watermarking are also included.