As a fundamental consideration for constructing the objective assessment method in the coded stereoscopic video, we examine the difference of the perception degree of the quality degradation in the stereoscopic video and its two dimensional (2D) video. At first, using subjective DSIS method, we obtain the mean opinion score (MOS-3D) of coded stereoscopic video, its score (MOS-L) of coded left-video, and its score (MOS-R) of coded right-video. Next, after we obtain an average value of MOS-L and MOS-R, and the difference between MOS-3D and its average, we define its difference as the improvement of subjective quality between stereoscopic video and two dimensional video. As a result of subjective assessment test, MOS-3D is always about 0.5 point higher than MOS of coded two dimensional video.
