StainedView: Variable-Intensity Light-Attenuation Display with Cascaded Spatial Color Filtering for Improved Color Fidelity

We present StainedView, an optical see-through display that spatially filters the spectral distribution of light to form an image with improved color fidelity. Existing light-attenuation displays have limited color fidelity and contrast, resulting in a degraded appearance of virtual images. To use these displays to present virtual images that are more consistent with the real world, we require three things: intensity modulation of incoming light, spatial color filtering with narrower bandwidth, and appropriate light modulation for incoming light with an arbitrary spectral distribution. In StainedView, we address the three requirements by cascading two phase-only spatial light modulators (PSLMs), a digital micromirror device, and polarization optics to control both light intensity and spectrum distribution. We show that our design has a 1.8 times wider color gamut fidelity (75.8% fulfillment of sRGB color space) compared to the existing single-PSLM approach (41.4%) under a reference white light. We demonstrated the design with a proof-of-concept display system. We further introduce our optics design and pixel-selection algorithm for the given light input, evaluate the spatial color filter, and discuss the limitation of the current prototype.