ITU-T J.245 PDF

This Recommendation specifies a subjective test method of picture quality assessed in the home. Picture quality is observed at user-end in home environment on computer monitor, or TV set (after set-top-box if needed) so only single stimulus method with subjects viewing the material once without the source reference is useful in this case. Details of SSCQE method especially adapted to observation quality in the home on computer screen or TV set are given in this Recommendation.

Laboratory subjective video quality testing seeks to separate video quality from all other variables (e.g., by using the professional quality monitor, the impact of monitor is removed from subjective scores). By contrast scores from this methodology will have several variables which cannot be separated from the subjective scores (e.g., impact of consumer quality monitor, potentially distracting wall decorations in home viewing environment). This subjective methodology is intended to more precisely analyse the viewing experience of a subject in its own home, and asks different questions than the laboratory tests.

This Recommendation is intended, in particular, for network designers and operators. It gives them guidelines for network design taking into account technical parameters as well as the number of sustainable streams and packet rate available for video services as well as the methodology of subjective picture quality evaluation. It may be also very helpful to service providers to quantify users' complaints about picture quality.

The method described in this Recommendation is not intended to replace a subjective experiment conducted in a controlled test environment (e.g., subjective laboratory) nor regulate consumer equipments.

NOTE 1 – The method in this Recommendation is experimental and has not yet been validated and adequate results have not been reviewed. Therefore, we caution the users to be careful in their use of this method. It should be also noted that the test result is not appropriate to be compared among different home test environments.

NOTE 2 – 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.