Results of the subjective test campaign


In our subjective evaluation we have adopted a Single Stimulus (SS) method in which a processed video sequence is presented alone, without being paired with its unprocessed (“reference”) version. The test procedure includes a reference version of each video sequence, which in this case is the packet loss free sequence, as a freestanding stimulus for rating like any other. Each test session involved only one subject per display assessing the test material. The subject is asked to rate the quality of the stimulus using the 5 point ITU continuous scale in the range [0−5]. For further details please refer to [1].

The CIF and 4CIF data were presented in separate test sessions: twenty-three subjects and seventeen subjects participated in the tests for CIF data at PoliMi and EPFL, respectively; twenty-one subjects and nineteen subjects participated in the tests for 4CIF data at PoliMi and EPFL, respectively. All subjects reported that they had normal or corrected to normal vision. Their age ranged from 24 to 40 years old. The subjects were naive assessors.

The raw subjective scores have been processed in order to obtain the final Mean Opinion Scores (MOS) and 95% Confidence Intervals (CI), according to the following steps [1] [2]:
 



Figure 1.