Deriving and evaluating eye-tracking controlled volumes of interest for variable-resolution video compression

Gaze coordinates are recorded from naive subjects watching a number of video clips. These are used to derive volumes of interest (VOIs) representing the mutual visual interest of the tested subjects. Video frames are then processed in variable resolution contingent on the VOI shapes to produce off-line foveated video. We report on bit rate savings between 30 and 54% due to off-line foveation proir to encoding with H.264. Subjective tests with a new set of subjects showed that off-line foveation in two of the three tested video clips had a positive effect on the experienced quality compared to unfoveated videos compressed with the same quality factor. We conclude that, in disagreement with previous works, it is advantageous to use off-line foveation to improve the performance of current state-of-art video compression technology. (c) 2007 SPIE and IS&T.