Multiresolution Image Watermarking: Algorithms And Applications

By using advanced signal processing techniques, digital watermarking embeds copyright notices and the signature directly into the multimedia contents to ensure the security of the data. With the success of the Internet, digital watermarking is playing a more and more important role in the modern society. However, there are many urgent problems to be solved before it becomes practical for different purposes, two of which are visible watermarking and invisible watermark detection. In this paper, methods have been proposed to address these problems.Compared with invisible watermarking, visible watermarking has attracted less attention since it was proposed. In the first part of this paper, some pioneer work has been done in this field. The properties and associated requirements of a visible watermark have been presented in detail from the perspective of applications. Furthermore, a novel wavelet domain adaptive visible watermarking algorithm has been proposed, which is distinguished for the following aspects:1. A new multiresolution visible watermarking framework that resembles the human visual system has been proposed. The watermark has been embedded into the host image in a manner of subband by subband.2. Based on human perception, luminance masking is designed to assist in low frequency watermark embedding.3. Each wavelet coefficient has been modeled by a generalized Gaussian distribution. Its standard deviation that well characterizes the activity of the current pixel is used to help high frequency watermark embedding.4. Since it is desirable for a visible watermark to have the degree of marking applied variable with the characteristics of the host image, we can effectively determine scaling factors by using the host features. Thus, we calculate scaling factors according to the characteristics of the host image in the proposed Method one.5. We first find that the watermark image can affect the performance of the...