ITU-T J.246-2008
Perceptual visual quality measurement techniques for multimedia services over digital cable television networks in the presence of a reduced bandwidth reference (Study Group 9)

Standard No.

ITU-T J.246-2008

Release Date

2008

Published By

ITU-T - International Telecommunication Union/ITU Telcommunication Sector

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ITU-T J.246-2008

Scope

This Recommendation provides guidelines and recommendations on the selection of appropriate perceptual video quality measurement equipment for use in multimedia applications when the reduced reference measurement method can be used. The reduced reference measurement method can be used when features extracted from the unimpaired reference video signal are readily available at the measurement point@ as may be the case of measurements on individual equipment or a chain in the laboratory or in a closed environment such as a cable television head-end. The estimation methods are based on processing video in VGA@ CIF@ and QCIF resolution. The validation test material contained both multiple coding degradations and various transmission error conditions (e.g.@ bit errors@ dropped packets). In the case where coding distortions are considered in the video signals@ the encoder can utilize various compression methods (e.g.@ MPEG-2@ H.264@ etc.). The models proposed in this Recommendation may be used to monitor the quality of deployed networks to ensure their operational readiness. The visual effects of the degradations may include spatial as well as temporal degradations (e.g.@ frame repeats@ frame skips@ frame rate reduction). The models in this Recommendation can also be used for lab testing of video systems. When used to compare different video systems@ it is advisable to use a quantitative method (such as that in [ITU-T J.149]) to determine the models' accuracy for that particular context. This Recommendation is deemed appropriate for telecommunications services delivered at 4 Mbit/s or less presented on mobile/PDA and computer desktop monitors. The following conditions were allowed in the validation test for each resolution: ? PDA/Mobile (QCIF): 16 kbit/s to 320 kbit/s ? CIF: 64 kbit/s-2 Mbit/s (C01 has several 2 Mbit/s) ? VGA: 128 kbit/s-4 Mbit/s (V13 has one HRC with 6 Mbit/s)

ITU-T J.246-2008 history

• 2008 ITU-T J.246-2008 Perceptual visual quality measurement techniques for multimedia services over digital cable television networks in the presence of a reduced bandwidth reference (Study Group 9)