Video quality

About: Video quality is a research topic. Over the lifetime, 13143 publications have been published within this topic receiving 178307 citations.

Generating visually representative video thumbnails

Abstract: An algorithm identifies a salient video frame from a video sequence for use as a video thumbnail. The identification of a video thumbnail is based on a frame goodness measure. The algorithm calculates a color histogram of a frame, and then calculates the entropy and standard deviation of the color histogram. The frame goodness measure is a weighted combination of the entropy and the standard deviation. A video frame having the highest value of frame goodness measure for a video sequence is determined as the video thumbnail for a video sequence.

System and method for automated testing of digital television receivers

Abstract: There is disclosed a system and method for the automated testing of digital television receivers. The automated test system comprises a digital video signal unit capable of sending a digital video test pattern to a digital television receiver. The digital video signal unit is capable of receiving from the digital television receiver a reconstructed digital video signal representing the digital video test pattern as displayed by the digital receiver television receiver. The automated test system comprises a test processing unit that is capable of comparing the digital video test pattern with the reconstructed digital video signal to determine the video quality of operation of the digital television receiver. The system and method of the present invention compares the digital video test pattern and the reconstructed digital video signal by 1) comparing the amount of jitter, and 2) comparing the signal to noise ratio, and 3) computing percentage similarity between an image block of each of the two video signals.

Study of MPEG-2 coding performance based on a perceptual quality metric

Abstract: Study of MPEG-2 Co ding Performance based on a PerceptualQuality MetricAndrea Basso* **_Ismail Dalgc*Fouad A. Tobagi* andChristian J. van den Branden Lambrecht**** Department of Electrical Engineering Stanford University** Telecommunication Laboratory Swiss Federal Institute of Tchnology*** Signal Processing Laboratory Swiss Federal Institute of TchnologyAbstractIn this paper some wel l known quality metrics suchas PSNR and the metric developed at Institute forTelecommunication Sciences (ITS) arereviewed.Their shortcomings in measuring quality of co-ded videocompared to subjective tests arepointedout. Then, a new video quality metric cal led Mo-ving Picture Quality Metric (MPQM) is presented.This metric models the human visual system andmatches correctly subjective evaluations. Compa-rative results in the case of constant bit rate (CBR)MPEG-2 codedsequences arepresented, showingthe superiority of MPQM over ITS and PSNR.1Intro ductionThe interest in multi-media applications - with astrong emphasis on video issues - is growing tre-mendously.Video assessment is a fundamentaland still not suciently explored asp ect of the cur-rent research on video co ding.Visual ob jectivemetrics that are coherent with quality as p erce-ived byhuman observers are b eginning to emergeonly recently.Furthermore very recently the con-cept of constant-quality video enco ding has b eenintro duced in [1] and further develop ed in [2].The motivation of this work is to determine theright kind of quality metric for devising a constant-qualityvariable bit rate (CQ-VBR) video enco dingscheme for MPEG-2 in view of an evaluation itsp erformances over ATM.In this pap er some well known quality metricsfor video such as the well known and widelyused Peak Signal to Noise Ratio (PSNR) and themetric develop ed at Institute for Telecommunica-its prop ertThis work was supp orted in part by NSF under grantNCR-9016032, and byPaci c Bell.tion Science (ITS) are reviewed. Then, a new vi-deo quality metric called Moving Picture QualityMetric (MPQM) is discussed. That metric is ba-sed on a mo del of the early stages of the human vi-sual system and it matches sub jectiveevaluationscorrectly. Results for the considered metrics areshown for constant bit rate (CBR) MPEG-2 co-ded sequences.The pap er is organized as follows. Sec. 2 over-views the literature on video quality assessmentand measurement. Sec. 3 illustrates the inadequ-acy of PSNR metric for video quality assessmentby means of a simple example. Sec.4 presentsthe ITS video quality metric and its p erformanceon MPEG-2 co ded video.Sec.5 discusses theMPQM. Some conclusive remarks end the pap er.2Stateoftheartinvideoquality assessment and me-asurement2.1First DevelopmentsVideo quality assessment plays a fundamental rolein the development of new and existing video co-ding algorithms.The interest for image qualityevaluation has b een strong since the sixties. Se-veral image quality metrics hae b een develop ed,such as the Strehl measure [3], based on the degra-dation to which an image is sub ject to, wheneverit passes di erent real optical systems compared tothe ideal case. Attempts with bivariate metrics ofimage qualityhave b een done in particular duringthe seventies. The reader is referred to [4] for areview.The mean square error has b een retained fory of b eing easily analytically tractable.Wilder [5] did a rather complete evaluation of dif-1

Video enhancement using multiple frame techniques

Abstract: A system is provided for that improves video quality and resolution. The system include a processor configured with logic to estimate an image from at least one observed image to produce an estimated image, the observed image having a lower spatial resolution than the estimated image. The processor is further configured with logic to simulate steps of an imaging process and compression process and update the estimated image with statistical and/or deterministic information if further optimization is needed, otherwise designate the estimated image as a solution.