Gradient-based Image Quality Assessment

An objective measure for image quality assessment based on a direct comparison of visual gradient information in the test and reference images is proposed. A perceptual model is defined to provide local estimates of gradient preservation and investigate perceptual importance pooling of such local quality estimates by using the lowest scores. The proposed perceptual pooled measure is validated using extensive subjective test results. Results indicate that the proposed measure is perceptually meaningful in that it corresponds well with the results of subjective evaluation and can outperform actual objective metrics.