Measuring perceived video quality of MPEG enhancement by people with impaired vision.
We used a new method to measure the perceived quality of contrast-enhanced motion video. Patients with impaired vision (n=24) and normally sighted subjects (n=6) adjusted the level of MPEG-based enhancement of 8 videos (4 min each) drawn from 4 categories. They selected the level of enhancement that provided the preferred view of the videos, using a decreasing-step-size staircase procedure. Most patients made consistent selections of the preferred level of enhancement, indicating an appreciation of and a perceived benefit from the MPEG-based enhancement. The selections varied between patients and were correlated with letter contrast sensitivity, but the selections were not affected by training, experience, or video category. We measured just noticeable differences directly for videos and mapped the image manipulation (enhancement in our case) onto an approximately linear perceptual space. These tools and approaches will be of value in other evaluations of the image quality of motion video manipulations.
Department of Electronics, University of York, York, UK.
Matthew
M
Fullerton
Russell L
RL
Woods
Fuensanta A
FA
Vera-Diaz
Eli
E
Peli
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002755:Choice Behavior; D015350:Contrast Sensitivity; D003491:Cybernetics / Q000379:methods; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods / Q000592:standards; D008268:Macular Degeneration; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D010470:Perceptual Masking; D012684:Sensory Thresholds; D014741:Video Recording / Q000592:standards*; D015354:Vision, Low; D019987:Persons with Visual Disabilities