A Blind Watermarking Algorithm Using DWT and DCT Techniques for Color Image

作者：Qian Guo; Guang Xue Chen; Jian Luo; Qi Feng Chen

来源：Applied Mechanics and Materials, 2015, 3784(1462): 179-182.

DOI：10.4028/www.scientific.net/AMM.731.179

• Color Image
• Arnold Scrambling
• Discrete Cosine Transform
• Discrete Wavelet Transform
• Mat-Lab Simulated Attacks

In this paper, a robust watermarking technique which combines features of Discrete Wavelet Transformation (DWT) and Discrete Cosine Transformation (DCT) is proposed. Firstly the original color image is converted from RGB space to Lab space. In this technique, DWT is used to decompose the luminance coefficients into various frequency and time scale. The block DCT is applied on DWT coefficients of middle frequency to provide high level of robustness. The encrypted watermark is embedded in it by comparison of the intermediate frequency coefficients. Then the color image is converted from Lab space to RGB space to get the watermarked image. Extracting the watermark does not need the original image and the original watermark, it is a blind watermarking method. Finally, the watermarked image is attacked. Peak signal-to-noise ratio (PSNR) value and the normalized correlation (NC) coefficient value are used to evaluate this technique. Simulation experiments show that the watermark is perceptually invisible, this method can achieve the highest possible robustness without losing the transparency.

• 出版日期2015
• 单位华南理工大学