ABSTRACT
This chapter introduces a multidimensional watermark scenario. The mutual independent watermarks, which are spread spectrum, are embedded in the low band to midband in the discrete cosine transform (DCT) domain in parallel, exploiting the properties of the human visual system. Without the original image, the watermark can be detected based on the joint probability distribution theory. The chapter presents the process of multidimensional watermark embedding, and introduces the watermark detection, hypothesis testing, and joint probability distribution. It also discusses how to detect the watermark without an initial image. In binary spread spectrum communication, there are two types of modulation: direct sequence and frequency hopped. Multidimensional watermarking in the low to mid-band of DCT coefficients improves the watermark robustness. In order to increase the compression ratio, one must take advantage of the redundancy in most image and video signals, including spatial redundancy and temporal redundancy.
