Applicability of No-Reference Visual Quality Indices for Visual Security Assessment

Author(s):  
Heinz Hofbauer ◽  
Andreas Uhl
2010 ◽  
Vol 53 (1) ◽  
pp. 75-95 ◽  
Author(s):  
Jing Sun ◽  
Zhengquan Xu ◽  
Jin Liu ◽  
Ye Yao

2012 ◽  
Vol 1 (3) ◽  
pp. 148 ◽  
Author(s):  
Helen Manolopoulou ◽  
Gregory Lambrinos ◽  
George Xanthopoulos

<p>Fresh-cut green bell peppers (<em>Capsicum annuum L.</em>) were stored in modified atmosphere packaging (MAP) made of impermeable high-density polyethylene film. Two in-packaging atmospheres and storage temperatures (0 <sup>o</sup>C and 5 <sup>o</sup>C) were tested. The respiration rate of the unpackaged produce and the in-package gas concentration, mass loss, firmness, skin colour, ascorbic acid and visual quality of the packaged produce were estimated. Cutting, increased respiration rate of the unpackaged produce by 24% compared to the intact produce for the same storage temperature. After 5 days of storage at 5 °C, significant O<sub>2</sub> depletion of the active modified atmosphere was found. Limited mass loss (0.4-0.5% of the initial mass) and firmness degradation were estimated in both storage temperatures due to the beneficial effect of packaging. The hue angle (h*) reduction was limited in all cases and the initial green colour was preserved. Initial ascorbic acid content was preserved at 0 °C, but significantly increased at 5 °C. The visual quality of the packaged produce was assessed by six trained panelists and found that was not significantly changed at 0 °C storage. In conclusion, the tested active MAP maintained the initial quality indices of fresh-cut peppers (<em>cv.</em> <em>Twingo F1</em>) for up to 10 days at 0 °C but not at 5 °C.</p>


2021 ◽  
Vol 91 ◽  
pp. 107071
Author(s):  
Jian Xiong ◽  
Xinzhong Zhu ◽  
Jie Yuan ◽  
Ran Shi ◽  
Hao Gao

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zhengguo Wu ◽  
Kai Zhang ◽  
Yannan Ren ◽  
Jing Li ◽  
Jiande Sun ◽  
...  

Selective encryption has been widely used in image privacy protection. Visual security assessment is necessary for the effectiveness and practicability of image encryption methods, and there have been a series of research studies on this aspect. However, these methods do not take into account perceptual factors. In this paper, we propose a new visual security assessment (VSA) by saliency-weighted structure and orientation similarity. Considering that the human visual perception is sensitive to the characteristics of selective encrypted images, we extract the structure and orientation feature maps, and then similarity measurements are conducted on these feature maps to generate the structure and orientation similarity maps. Next, we compute the saliency map of the original image. Then, a simple saliency-based pooling strategy is subsequently used to combine these measurements and generate the final visual security score. Extensive experiments are conducted on two public encryption databases, and the results demonstrate the superiority and robustness of our proposed VSA compared with the existing most advanced work.


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