Stereo Image Coding: Effects of Stereo Mismatches on Image-Quality

The present research sought to understand how the human visual system responds to stereo image sequences where the image-quality of the left-and right-eye views differ. Viewers received the left-eye view at a higher quality than the right-eye view, and rated the combined overall subjective quality of the sequence. Three stereo image sequences were used for assessment. Each sequence, in the ITU-601 format, was 10-sec in duration and the images for the left-and right-eye views were coded independently at bit-rates of 6, 3, 2 and 1 Mbits/sec. These were combined in a partial-factorial manner (i.e. left:right, 6:6, 6:3, 6:2, 6:1, 3:3, 3:2, and 3:1). The resulting stereo sequences were viewed by 26 subjects, and rated in terms of subjective image-quality. The rating methodology was based on the double-stimulus continuous-quality scale method described in ITU-R Recommendation 500. The results showed that the subjective quality of a stereo image fell approximately midway between the quality of the left-and right-eye views. For video coding this implies that the human visual system can tolerate discrepancies in the quality of left-and right-eye views in a stereo display. The results are consistent with known properties of binocular vision, in particular with the averaging of brightness of stimuli presented to the two eyes.

Published

1996-10

Content type

Original Research

DOI

10.5594/M001274

ISBN

978-1-61482-947-8