Adaptive digital watermarking algorithm based on energy analysis of wavelet coefficients block
基于小波系数块能量分析的自适应数字水印算法

To enhance the robustness of watermark, an improved digital watermarking algorithm based on wavelet transform was proposed. The third level detail sub-images decomposed the original image using three levels DWT(Discrete Wavelet Transform) were divided into non-overlap blocks. Then the blocks, which were more adaptable to embed watermark, were selected by block energy analysis. At the end, combining with the properties of human visual system, the watermark was adaptively embedded into the largest coefficients which belonged to the selected blocks. Theoretical analysis and experiment results show that the watermark generated with the proposed algorithm is imperceptible and more robust.