Relation between visual effects and gain of motion parallax

This paper examines visual effects of motion parallax (MP) which is an important element of depth perception. A display technology was developed which does not cause a delay of motion parallax to a viewer watching an image with a motion parallax related to viewpoint position. Using this apparatus, a method of control was examined which affects a viewer's emotion by changing the magnitude of the motion parallax. A term “gain of motion parallax Gm” which represents the magnitude of a motion parallax is defined. An assumption is made that a visual effect induced by an image with a motion parallax depends on Gm. To prove this assumption, the undetectable threshold of a delay of a motion parallax was found to be approximately 60 ms. It was confirmed that the motion‐parallax display apparatus developed has shorter delay than this value. By changing the value of Gm, subjective evaluations were carried out for three evaluation items: “sensation of depth,” “reality” and “linkage.” The results show that these three items form functions of Gm which are “saturation shape,” “dull peak shape” and “sharp peak shape,” respectively.