Video quality evaluation using ST-CIELAB

Xin Tong, David J. Heeger, Christian J. Van Den Branden Lambrecht

Abstract: With the rapid growth of internet and digital video technology, perceptual assessment of video quality is becoming more important. An automatic assessment procedure based on some human vision model is desirable because subjective video quality measurement is costly and time- consuming. We propose a video quality metric called spatio- temporal CIELAB (ST-CIELAB). ST-CIELAB is an extension of the spatial CIELAB (S-CIELAB) image quality metric, that is itself an extension of the CIELAB color standard. The ST- CIELAB metric is based on a spatial, temporal, and chromatic model of human contrast sensitivity. Few such video quality metrics, accounting for human temporal as well as spatial sensitivities, have been proposed and they are based on multi-resolution, subband decomposition, models of human pattern sensitivity. ST-CIELAB is single-resolution which offers computational advantages over multi-resolution models. The ST-CIELAB rating is in units of JND, providing a meaningful interpretation of the rating. The ST-CIELAB metric was designed to fit published contrast sensitivity data, and ST-CIELAB is backward compatible with the well- established CIELAB standard, i.e., it reduces to CIELAB for uniform color fields. We tested the ST-CIELAB metric by performing psychophysics experiments with MPEG video sequences to see how well ST-CIELAB ratings correlate with subjective ratings.