The importance of correct focus cues in 3d stereoscopic imagery.

作     者：Anantha Anantha Krishnan 

作者单位：Bangor University 

学位级别：博士

导师姓名：Simon Watt

授予年度：2023年

摘      要：Stereoscopic 3-D display technologies aim to provide a compelling, realistic sense of 3-D depth. Theoretically, this could be achieved by having a system that can project the same light rays coming from the real world via a display. Recent advances in rendering, display, and image acquisition have made it possible to present almost all depth cues accurately. Focus cues, including the eye s focusing response to image blur (accommodation) and the pattern of retinal blur arising from objects at varying distances (retinal blur gradient), remain challenging to replicate accurately, however. In conventional stereoscopic displays, focus cues are incorrect, as the depth is specified by the screen surface and not by the position of the content in the scene. This issue causes two problems: firstly, the unnatural pattern of oculomotor responses elicited when viewing the 3-D scene (inaccurate accommodation signals), and the appearance (inaccurate retinal blur gradient) may signal the unnaturalness of depth in the scene (Hibbard et al., 2017). Secondly, the inconsistency between depth specified by vergence from disparity and focus cues results in a conflict commonly known as vergence-accommodation conflict. The visual system s effort to resolve this conflict causes visual discomfort and reduced stereoacuity (Watt et al., 2005 a; Hoffman et al., 2008; Shibata et al., 2011). There is an increasing demand for stereoscopic 3-D displays that can elicit realistic depth and have minimal to no user issues. Several technologies have tried to address the issue with incorrect focus cues, but all are computationally intensive, require specialist hardware, and compromise image quality. Hence, the value of presenting focus cues accurately needs to be fully understood. In Chapter 2, we measured the vergence distances (zone of good stereo depth perception) around the screen, where stereoscopic depth perception remains effective despite incorrect focus cues. To understand whether all users would