Crosstalk in automultiscopic 3-D displays: blessing in disguise?

Ashish Jain, Janusz Konrad, Andrew J. Woods, Neil A. Dodgson, John O. Merritt, Mark T. Bolas, Ian E. McDowall
2007 Stereoscopic Displays and Virtual Reality Systems XIV  
Most of 3-D displays suffer from interocular crosstalk, i.e., the perception of an unintended view in addition to intended one. The resulting "ghosting" at high-contrast object boundaries is objectionable and interferes with depth perception. In automultiscopic (no glasses, multiview) displays using microlenses or parallax barrier, the effect is compounded since several unintended views may be perceived at once. However, we recently discovered that crosstalk in automultiscopic displays can be
more » ... c displays can be also beneficial. Since spatial multiplexing of views in order to prepare a composite image for automultiscopic viewing involves sub-sampling, prior anti-alias filtering is required. To date, anti-alias filter design has ignored the presence of crosstalk in automultiscopic displays. In this paper, we propose a simple multiplexing model that takes crosstalk into account. Using this model we derive a mathematical expression for the spectrum of single view with crosstalk, and we show that it leads to reduced spectral aliasing compared to crosstalk-free case. We then propose a new criterion for the characterization of ideal anti-alias pre-filter. In the experimental part, we describe a simple method to measure optical crosstalk between views using digital camera. We use the measured crosstalk parameters to find the ideal frequency response of anti-alias filter and we design practical digital filters approximating this response. Having applied the designed filters to a number of multiview images prior to multiplexing, we conclude that, due to their increased bandwidth, the filters lead to visibly sharper 3-D images without increasing aliasing artifacts. Keywords: 3-D automultiscopic displays, interocular crosstalk, anti-alias filtering As recently shown, prior to multiplexing views in order to prepare a composite image for display on a lenticular (or parallax-barrier) 3-D screen, suitable low-pass filtering is required. 6-8 That filtering removes highfrequency details from individual views since otherwise sub-sampling, an inherent step in view multiplexing, would lead to aliasing perceived as color fringing at sharp object boundaries, Moire patterns, granular noise, etc. However, the simple sub-sampling model used to date ignores the optical crosstalk effects present in lenticular and parallax-barrier multiview displays. In this paper, we consider the impact of crosstalk in spatially-multiplexed automultiscopic 3-D displays on optimal view multiplexing and, in particular, on anti-alias filter design. First, we propose a simple linear model for view multiplexing accounting for optical inter-view crosstalk. We then derive a mathematical expression for
doi:10.1117/12.707982 fatcat:h77jxzmeufdpfnpzaqsp7obffe