EEG-BASED ASSESSMENT OF PERCEIVED QUALITY IN COMPLEX NATURAL IMAGES

Psychophysiological methods gained a lot of interest in recent years as a potential remedy for the inherent flaws of overt psychophysical quality assessment methods. Among the psychophysiological monitoring methods, electroencephalography showed to be a promising choice. Specifically, the steady state visually evoked potential (SSVEP) was shown to provide a reliable neural correlate of perceived visual quality for degraded texture image patches. This paper evaluates the feasibility of the SSVEP-based quality assessment approach for more realistic and practically relevant images. To this end, we collected overt, psychophysical responses and neural, psychophysiological responses of 14 participants to 6 HD images each compressed at 4 distortion levels. The psychophysical part followed the Degradation Category Rating procedure. In the subsequent psychophysiological part, the subjects were presented with distorted and reference images alternating at a fixed rate of 5 Hz to elicit the SSVEP. We show that the amplitude of the 1st harmonic of the SSVEP correlates significantly with the psychophysical responses (|ρ| = 0.85, p < 0.05) in a single channel analysis at the Oz electrode