Anastasia Zvezdakova

Anastasia Zvezdakova, Sergey Zvezdakov, Dmitriy Kulikov et al.

Video quality measurement takes an important role in many applications. Full-reference quality metrics which are usually used in video codecs comparisons are expected to reflect any changes in videos. In this article, we consider different color corrections of compressed videos which increase the values of full-reference metric VMAF and almost don't decrease other widely-used metric SSIM. The proposed video contrast enhancement approach shows the metric inapplicability in some cases for video codecs comparisons, as it may be used for cheating in the comparisons via tuning to improve this metric values.

Anastasia Zvezdakova, Dmitriy Kulikov, Denis Kondranin et al.

This paper analyses the application of no-reference metric NIQE to the task of video-codec comparison. A number of issues in the metric behaviour on videos was detected and described. The metric has outlying scores on black and solid-coloured frames. The proposed averaging technique for metric quality scores helped to improve the results in some cases. Also, NIQE has low-quality scores for videos with detailed textures and higher scores for videos of lower bitrates due to the blurring of these textures after compression. Although NIQE showed natural results for many tested videos, it is not universal and currently can not be used for video-codec comparisons.