Research of Digital Image Watermarking Algorithm Based on Wavelet Transform
|School||Central China Normal University|
|Course||Applied Computer Technology|
|Keywords||Discrete wavelet transform (DWT) Human visual system (HVS) Singular value decomposition (SVD) Blind Watermarking Image Scrambling Robustness|
With the rapid development and wide application of multimedia technology and network technology , the transmission and sharing of multimedia data become increasingly common. These data can be easily copied and modified , therefore the copyright protection of the digital product has become a very important issue. As an effective means for copyright protection of digital products , digital watermarking technology came into being . Digital watermarking technology is generally specific watermark information is embedded into the digital products , digital products copyrighted to confirm the case or to ensure true and reliable data . For digital watermarking technology, the general requirements of the embedded watermark information is not visible , and able to resist a variety of attacks, having a certain robustness . Firstly, from the concept of digital watermarking , classification , made ??an overview of the basic model , the watermarking algorithm to study the background of its main application areas of digital watermarking technology . Second, a brief introduction to the definition of the wavelet transform , wavelet transform the nature of the two - dimensional orthogonal wavelet decomposition , Mallat algorithm and wavelet theory in digital watermarking . Subsequently, two digital image watermarking algorithm based on wavelet transform . The first algorithm is based on the characteristics of the human visual system (HVS) image watermarking algorithm . The algorithm will be meaningful binary image watermark instead of a random sequence , then all first watermark Arnold scrambling encryption embedded into the low frequency sub-band coefficient . The algorithm makes use of the human visual system (HVS) characteristics to enhance the robustness of the watermark and guarantee the invisibility of the watermark embedding strength adaptively adjust . The second algorithm is a digital image watermarking algorithm based on discrete wavelet transform (DWT) and singular value decomposition (SVD) combined . The algorithm of the original image for Wavelet decomposition and wavelet decomposition of the low-frequency sub- band block , each a singular value decomposition , select each piece of the largest singular value through quantitative methods embedded after the watermark Arnold scrambling information . The watermark extraction does not require the original image, but is limited by the key , and does not know the key can not be correctly restored digital watermark . The experimental results show that the algorithm has good invisibility , robustness and security .