ITU-T J.244 PDF

This Recommendation specifies calibration methods which report alignment shifts in both space and time of processed (e.g., compressed, transmitted, and decompressed) video sequences with respect to corresponding source video sequences. The methods also compute gain and offset of processed video sequences. The methods require that spatial and temporal shifts must be constant. Furthermore, the gain and offset must be constant. The methods in this Recommendation are applicable to:

• reporting shifts that can be used to register source and processed video sequences in space and time;

• reporting gains, and offsets of video levels that can be used to calibrate processed video sequences with respect to the source. These methods can be used to report calibration differences between the source and processed video sequences.

These values may be used to repair processed video sequences. Table 1 summarizes the required bandwidth and Table 2 shows the ranges of spatial and temporal shifts for which the methods in this Recommendation were tested.

Applications

Intended applications for these methods include, but are not limited to, assessing the operational readiness of video transmission systems that contain compression/transmission/decompression components, obtaining calibration estimates for correcting processed video sequences before measuring subjective or objective picture quality, and verifying that video transmission systems meet specified calibration requirements.

Limitations

The methods presented in this Recommendation require access to both source and processed video sequences. The spatial and temporal shifts must remain constant for the entire processed video sequences. Furthermore, the gain and offset must be fixed.

NOTE – The structure and content of this Recommendation have been organized for ease of use by those familiar with the original source material; as such, the usual style of ITU-T recommendations has not been applied.