Research Topics



Blind Contrast Enhancement Assessment

descriptif

The contrast of outdoor images acquired under adverse weather conditions, especially foggy weather, is altered by the scattering of daylight by atmospheric particles. As a consequence, differentmethods have been designed to restore the contrast of these images. However, there is a lack of methodology to assess the performances of the methods or to rate them. Unlike image quality assessment or image restoration areas, there is no easy way to have a reference image, which makes the problem not straightforward to solve. In this paper, an approach is proposed which consists in computing the ratio between the gradient of the visible edges between the image before and after contrast restoration. In this way, an indicator of visibility enhancement is provided based on the concept of visibility level, commonly used in lighting engineering. Finally, the methodology is applied to contrast enhancement assessment and to the comparison of tone-mapping operators.

Publications
  1. Hautière, N., Tarel, J.-P., Aubert, D. and Dumont, E. Blind Contrast Enhancement Assessment by Gradient Ratioing at Visible Edges. In Image Analysis and Stereology, 27 (2): 87-95, 2008.    
  2. Hautière, N., Tarel, J.-P., Aubert, D. and Dumont, E. Blind Contrast Restoration Assessment by Gradient Ratioing at Visible Edges. In International Congress for Stereology (ICS'07), Saint-Etienne, France, 2007.  

Slides

descriptifICS2007 presentation

Related topics

Physics-based Vision

Performance Evaluation

Atmospheric visibility enhancement
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