ANSI T1A1 Contribution T1A1.5/94-110, January 17, 1994.

Corrections and Extensions to T1A1.5/93-152

Stephen Wolf; Margaret H. Pinson

Abstract: Contribution T1A1.5/93-152 summarized the methods of measurement for objective video quality parameters based on the Sobel-filtered image and the motion difference image that were submitted prior to conducting the T1A1 subjective experiment (this experiment collected 625 mean opinion scores - i.e., 25 test scenes passed through 25 different video transmission systems that ranged in bit rate from 64 kb/sec to 45 Mb/sec). This contribution presents (1) one minor correction to the recommended value for the fraction above threshold in contribution T1A1.5/93-152, and (2) a method for estimating the video delay uncertainty of the automated time alignment algorithm presented in section 3 of contribution T1A1.5/93-152 (non-zero video delay uncertainty may result when dynamic time warping, or variable video delay, is present in the video transmission system, or when there is a substantial number of dropped video frames), (3) a method for using this video delay uncertainty in the computation of the parameters presented in T1A1.5/93-152, and (4) an improved motion spike detector that could be used for computing parameters p10 and p11 in T1A1.5/93-152.

Keywords: coding; performance; measurements; video; quality; metrics; parameters; objective; delay; dropped; frames; variable; Testing; compression; artifacts; motion

For technical information concerning this report, contact:

Margaret H. Pinson
Institute for Telecommunication Sciences
(303) 497-3579

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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