Multispectral Digital Projection

Multispectral display technology employing more than 3 primaries and utilizing spectral color reproduction image processing rather than traditional trichromatic models is key to expanding color gamut, rendering fully accurate color reproduction and minimizing observer metamerism. In the presented work, two LCD HDTV projectors are modified by optical filtration to generate 6 unique and controllable primary spectra. A full spectral reconstruction model is then proposed and executed for reproducing target color patches under specified illumination. This system is built in an effort to assess the feasibility of simple retrofit strategies for abridged multispectral display from native P3 and sRGB-optimized devices. Due to narrow spectral signatures in each of the LCD-modulated RGB primaries, spectral reconstruction and observer metamerism improvements over a simple 3-primary system are negligible. Significant improvements, however, are simulated by optimization of ideal primary spectra for specific target sets, providing basis for future system refinement. Also concerning in the constructed system are inherent spatial non-uniformities, scene-dependent flare characteristics and long-term colorimetric drift that pose several engineering challenges for a fully functional system.

Optimizing Multiprimary Spectral Projection
“Optimizing Spectral Color Reproduction in Multiprimary Digital Projection,” Proc. Color Imaging Conference 19, San Jose, CA, November 2011

Summary of the prototype 6-primary multispectral projector built at RIT

Spectral target reconstruction algorithm - more detail is provided in the following paper published in the Proceedings of the 19th Color Imaging Conference held in San Jose in 2011