Abstract: According to the described method, interframe similarities s(i) are calculated for the frames of the video sequence, each interframe similarity s(i) being indicative of the similarity of two consecutive frames i?1, i. As it has been found, an analysis of the interframe similarities allows to determine various parameters that are characteristic for the mean opinion score MOS, such as the downsampling rate, pausing, or a noise-dependence of the interframe similarity at the keyframes. An objective mean opinion score MOSo being a value close to the mean opinion score is derived as a value linear in the pausing parameter, a keyframe distance parameter and further quality parameters measured in the spatial domain, corrected by a second value being an exponential model in the downsampling rate.