Measurement of compression-induced temporal artifacts in subjective and objective video quality assessment

Temporal pooling and temporal defects are the two di erences between image and video quality assessment. Whereas temporal pooling has been the object of two recent studies, this paper focuses on the rarely addressed topic of compression-induced temporal artifacts, such as mosquito noise. To study temporal aspects in subjective quality assessment, we compared the perceived quality of two versions of a mosquito noise corrector: one purely spatial and the other spatio-temporal. We set up a paired-comparison experiment and choose videos whose compression mainly creates temporal artifacts. Results proved the existence of a purely temporal aspect in video quality perception. We investigate the correlation between subjective results from the experiment and three video metrics (VQM, MOVIE, VQEM), as well as two temporally-pooled image metrics (SSIM and PSNR). SSIM and PSNR metrics nd the corrected sequences of better quality than the compressed ones but do not distinguish spatial and spatio-temporal processings. The confrontation of those results with the VQM and Movie objective metrics show that they do not account for this type of defects. A detailed study highlights that either they do not detect them or the response of their temporal component is masked by the one of their spatial components.