Content‐Independent Multi‐Spectral Display Using Superimposed Projections

Abstract

Figure 1: (a) Multi-spectral display system setup with three modified conventional 3-primary projectors, a conventional LCD 3-primary projector for comparison and a high spatial and spectral resolution spectroradiometer (SOC-730 hyperspectral camera) for measurements. (b)The candidate set of 30 primaries used for our prototype, (c) the existing r, g and b filters of the projectors, (d) the 9 filters chosen by our algorithm, (e) the 9-primaries generated by multiplying the r, g and b primaries with the 9 chosen filters. (f) and (g) show the results of our 9-primary multi-spectral display (left) when compared with a conventional 3-primary display (right). AbstractMany works focus on multi-spectral capture and analysis, but multi-spectral display still remains a challenge. Most prior works on multi-primary displays use ad-hoc narrow band primaries that assure a larger color gamut, but cannot assure a good spectral reproduction. Content-dependent spectral analysis is the only way to produce good spectral reproduction, but cannot be applied to general data sets. Wide primaries are better suited for assuring good spectral reproduction due to greater coverage of the spectral range, but have not been explored much. In this paper we explore the use of wide band primaries for accurate spectral reproduction for the first time and present the first content-independent multi-spectral display achieved using superimposed projections with modified wide band primaries. We present a content-independent primary selection method that selects a small set of n primaries from a large set of m candidate primaries where m > n. Our primary selection method chooses primaries with complete coverage of the range of visible wavelength (for good spectral reproduction accuracy), low interdependency (to limit the primaries to a small number) and higher light throughput (for higher light efficiency). Once the primaries are selected, the input values of the different primary channels to generate a desired spectrum are computed using an optimization method that minimizes spectral mismatch while maximizing visual quality. We implement a real prototype of multi-spectral display consisting of 9-primaries using three modified conventional 3-primary projectors, and compare it with a conventional display to demonstrate its superior performance. Experiments show our display is capable of providing large gamut assuring a good visual appearance while displaying any multi-spectral images at a high spectral accuracy.

A Monocular Projector-Camera System Using Modular Architecture

“…We showed that our modular architecture based on relay optics could support the extension of projector performance beyond the capability of projector hardware and, in particular, the HDR projection. The modular architecture would allow us to build other types of high performance projection systems, such as multi-band projection, by combining more than two display panels with slightly different spectral properties [41]. However, adding optical components also leads to additional aberrations and reduction of peak luminance.…”

Recent Advances in Projection Mapping Algorithms, Hardware and Applications

“…However, while these reproduce an acceptable metameric spectrum as perceived by the CIE standard observer, it is generally a low fidelity approximation of the real spectrum which is not correct for other observers. Li et al take an opposite strategy, i.e., explore the use of wide band primaries for accurate spectral reproduction [LMLG15] (cf. Figure ).…”

“…Multispectral projection system using superimposed projectors with varying wide‐band spectral color filters. [LMLG15]. In comparison with a standard LCD projector, the color saturation and color gamut is enhanced.…”

Adaptive color display via perceptually-driven factored spectral projection

“…Multi-primary displays usually aim for a wide color gamut, as perceived by a human observer. Related algorithmic problems include selecting the optimal color primaries [Ben-Chorin and Eliav 2007;Long and Fairchild 2011;Li et al 2015] as well as gamut mapping (e.g., [Banterle et al 2011]), where pixels of an image are processed to fit within the fixed gamut provided by a display. Gamut expansion can also help to optimize image presentation with large-gamut displays [Majumder et al 2010].…”

“…For example, we demonstrate a custom-built hyperspectral projection system that is closely related to the design introduced by Rice et al [2007] and later used by Mohan et al [2008] in the supplemental document. Hyperspectral projectors could achieve simultaneous color and spectral match of displayed target content, which may be beneficial for some applications [Li et al 2015].…”