Subjective quality assessment of asymmetric stereoscopic 3D video

In asymmetric stereoscopic video compression, the views are coded with different qualities. According to the binocular suppression theory, the perceived quality is closer to that of the higher-fidelity view. Hence, a higher compression ratio is potentially achieved through asymmetric coding. Furthermore, when mixed-resolution coding is applied, the complexity of the coding and decoding is reduced. In this paper, we study whether asymmetric stereoscopic video coding achieves the mentioned claimed benefits. Two sets of systematic subjective quality evaluation experiments are presented in the paper. In the first set of the experiments, we analyze the extent of downsampling for the lower-resolution view in mixed-resolution stereoscopic videos. We show that the lower-resolution view becomes dominant in the subjective quality rating at a certain downsampling ratio, and this is dependent on the sequence, the angular resolution, and the angular width. In the second set of the experiments, we compare symmetric stereoscopic video coding, qualityasymmetric stereoscopic video coding, and mixed-resolution coding subjectively. We show that in many cases, mixedresolution coding achieves a similar subjective quality to that This work was supported by the Academy of Finland, (application number 129657, Finnish Programme for Centres of Excellence in Research 2006–2011). P. Aflaki (B) · M. Gabbouj Department of Signal Processing, Tampere University of Technology, Tampere, Finland e-mail: [email protected] M. Gabbouj e-mail: [email protected] M. M. Hannuksela Nokia Research Center, Tampere, Finland e-mail: [email protected] of symmetric stereoscopic video coding, while the computational complexity is significantly reduced.