A validation of combined metrics for color image quality assessment

Abstract

Since most of even recently proposed image quality assessment metrics are typically applied for a single color channel in both compared images, a reliable color image quality assessment is still a challenging task for researchers. One of the major drawbacks limiting the progress in this field is the lack of image datasets containing the subjective scores for images contaminated by color specific distortions. After the publication of the TID2013 dataset, containing i.a. images with 6 types of color distortions, this situation has changed, however there is still a need of validation of some recently proposed grayscale metrics in view of their applicability for color specific distortions. In this paper some results obtained using different approaches to color to grayscale conversion for some well-known metrics as well as for recently proposed combined ones, are presented and discussed, leading to meaningful increase of the prediction accuracy of image quality for color distortions.