ABSTRACT
This chapter discusses the strategy of enlarging the watermarking capacity by breaking local spatial similarity in an image to generate more significant coefficients of the transformed image. It describes the reference register (RR) and explains the proposed watermarking algorithm. The frequency-domain watermarking would be robust since the embedded watermarks are spread out all over the spatial extent of an image. W. L. Zhao et al. presented a wavelet-domain watermarking algorithm based on chaotic map. In order to obtain proper coefficients from a transformed image for embedding and extracting watermarks, the concept of RR is developed. The proposed algorithm consists of two procedures: watermark embedding and watermark extracting. The watermark-embedding and extracting procedures are conducted on the discrete Cosine Transform coefficients located by the RR. One solution to achieve data security is the digital watermarking technology that embeds hidden information or secret data in a host image.
