New models of visual saliency: Contourlet transform based model and hybrid model

Author(s):  
Ilyass Abouelaziz ◽  
Mohammed El Hassouni
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jinhua Liu ◽  
Jiawen Huang ◽  
Yuanyuan Huang

We have proposed an image adaptive watermarking method by using contourlet transform. Firstly, we have selected high-energy image blocks as the watermark embedding space through segmenting the original image into nonoverlapping blocks and designed a watermark embedded strength factor by taking advantage of the human visual saliency model. To achieve dynamic adjustability of the multiplicative watermark embedding parameter, the relationship between watermark embedded strength factor and watermarked image quality is developed through experiments with the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM), respectively. Secondly, to detect the watermark information, the generalized Gaussian distribution (GGD) has been utilized to model the contourlet coefficients. Furthermore, positions of the blocks selected, watermark embedding factor, and watermark size have been used as side information for watermark decoding. Finally, several experiments have been conducted on eight images, and the results prove the effectiveness of the proposed watermarking approach. Concretely, our watermarking method has good imperceptibility and strong robustness when against Gaussian noise, JPEG compression, scaling, rotation, median filtering, and Gaussian filtering attack.


1975 ◽  
Vol 20 (5) ◽  
pp. 431-432
Author(s):  
ANTHONY G. GREENWALD

1969 ◽  
Vol 14 (8) ◽  
pp. 421-423 ◽  
Author(s):  
W. ROBERT DIXON

2016 ◽  
pp. 5-33 ◽  
Author(s):  
V. Mau

The paper deals with 2015 trends and challenges for social and economic policy in the nearest future. The analysis of global crisis includes: uneven developments in the leading advanced and emerging economies; new models of economic growth which look differently in different countries; prospects of globalization and challenges of ‘regional globalization’; currency configurations of the future; energy prices dynamics and its influence on political and economic prospects of particular states. Current challenges are discussed in the context of previous 30 years. Among the main topics on Russia, there are approaches to a new growth model, structural transformation (including import substitution issues), economic dynamics, budget and monetary outlines, social issues. The priorities of economic policy are also considered.


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