Research On The Watermark Method Based On HVME And Contourlet

Due to the better decomposition characteristics of contourlet transform compared with wavelet transform, the research combined human visual system with contourlet transform is a new research hot spot of digital watermarking technology.By analyzing the characteristics of contourlet transform, human visual system and HVME (Human Vision Masking Effection), a new digital watermarking algorithm is proposed which is based on HVME and contourlet transform.Firstly, by means of the features of contourlet transform that every decomposition sub-band is able to reflect the image's contours and edges, combining with HVME, we select the decomposition low-pass sub-band by analyzing image brightness characteristics, texture characteristics and directional characteristics to calculate the amounts of watermark embedding.Secondly, according to the shortage that the reconstructed image would exceed gray range and loss of watermark information if the transform coefficients of boundary been superimposed with watermark, we classify the transform coefficients by superimposing watermark to boundary coefficients by control mode, and superimposing watermark to the other coefficients by additional mode.Finally, experimental results were analyzed and discussed, and the results verify the effectiveness of the proposed algorithm.