Watermarking Algorithm In The Image

This thesis is concerned with one of the most popular research topics in the field of information hiding, the digital watermarking technology, with emphasis placed on its applications in digital images. Firstly, it introduces the basic concepts of digital watermarking and the main characteristics of its algorithms, implements some typical algorithms, and then makes assessment and evaluations by virtue of the corresponding experiment results; Secondly, it discusses in a systematic way the scrambling-based preprocessing methods for digital watermarking, analyzes the levels of image scrambling, introduces a new concept of "scrambling degree" together with its measuring formulas. Then, both the K-sampling theory and the HVS (human visual system) theory are applied to digital watermarking embedment, resulting in two new strategies and the relevant algorithms as well as their implementations. The experimental results demonstrate that the present algorithms are of robustness and good imperceptibility. Finally, an associated digital image watermarking software system is developed.