<title>Computer-based testing of digital video quality</title>

Abstract

Conventional analog video test measurements are generally not adequate for digital video, especially compressed video. This is because digital video distortion and artifacts often are spatially and temporally discrete phenomena. Most analog measurements assume that errors are of a continuous, linear nature. The only alternative to data has been subjective testing. Formal subjective tests (e.g., CCIR 500) can provide reliable, relative measures of video quality. However, such testing is time-consuming and expensive. Objective testing methods are needed to provide efficient, repeatable measures of video quality. A further advantage of objective testing is that it can provide greater insights into the nature of impairments. Presently, no standardized objective measures exist for digital video. However, pioneering work has been done by NTIA, NASA, ACATS and others to quantify the quality of digital video codecs. We have implemented some of the published measurements and others of our own design on a low-cost workstation. These measures utilize complex digital image processing techniques to analyze differences between source and processed video sequences. This paper presents formulations of these measurements and describes our implementation of an automated system to capture and test digital video quality.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.