**7. Conclusions**

The large amount of studies developed for this purpose related to quality assessment gives a general idea about the importance of this theme in video compression. The evolution of metrics and techniques is constant, finding the best ways of evaluating the quality of video sequences.

A complete state of the art in quality assessment has been developed, describing techniques of subjective and objective assessment, with the most common artifacts and impairments derived from compression and transmission. In objective research,
