The Relationship Between Performance and Spatial-Temporal Region Size for Reduced-Reference, In-Service Video Quality Monitoring Systems

This paper presents objective-to-subjective correlation results for a reduced-reference, in-service, video quality monitoring system. This reduced-reference system utilizes quality parameters that are computed by comparing features extracted from spatial-temporal (S-T) regions of the input video stream with identical features extracted from the output video stream. The amount of reducedreference information that is required to compute the quality parameters is inversely related to the size of the ST region. Smaller amounts of reference information (i.e., larger S-T regions) are desired since less transmission or storage bandwidth is required for the reference information. However, objective-to-subjective correlation drops off if the S-T region size becomes too large. In this paper we examine the tradeoffs between objective-tosubjective correlation results and S-T region size. Correlation results for S-T region sizes from 8 vertical lines x 8 horizontal pixels x 2 video frames to 128 x 128 x 24 are presented. These results utilized a total of nine subjectively rated data sets that span an extremely wide range of bit rates and compression techniques. Thus, designers of television video systems as well as Internet video streaming systems may use the results.