ITU-T J.342 PDF

This Recommendation provides a video quality measurement method for use in high definition television (HDTV) non-interactive applications when the reduced reference (RR) measurement method can be used. The model was compared to subjective quality scores obtained using [b-ITU-T P.910]. Analyses showed that the accuracy of this model was equivalent to that of peak signal-to-noise ratio (PSNR).

For the RR model to operate correctly, the unimpaired source video should be available for the model to extract parameters. These extracted parameters as well as the degraded video sequence are the inputs to the RR model. The estimation method performs both calibration (i.e., gain/offset and spatial/temporal registration) and objective video quality estimation.

The validation test material contained both ITU-T H.264 and MPEG-2 coding degradations and various transmission error conditions (e.g., bit errors, dropped packets). The model 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. The model 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 [b-ITU-T J.149]) to determine the model's accuracy for that particular context.

This Recommendation is deemed appropriate for telecommunication services delivered between 1 Mbit/s and 30 Mbit/s. The following resolutions and frame rates were considered in the validation test:

• 1080i 60 Hz (29.97 fps);

• 1080p (25 fps);

• 1080i 50 Hz (25 fps);

• 1080p (29.97 fps).

Note that 720p was considered in the validation test plan as part of the test condition of the hypothetical reference circuit (HRC). Because currently 720p is commonly upscaled as part of the display, it was felt that 720p HRCs would more appropriately address this format.