Smart Dimming Sunglasses for Photophobia Using Spatial Light Modulator
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We propose a smart dimming sunglasses system for individuals with photophobia, especially those who are easily irritated by light intensity. The system uses a spatial light modulator (SLM) to selectively filter light entering the eye based on the scene detection of a camera. By controlling the transmittance of each pixel on the SLM using a modulation function, the proposed sunglasses enable an automated non-linear field of view dimming and also flexible light modulation that meets the photophobic user's visual requirements. Meanwhile, an occlusion mask created on the SLM, which possesses low transmittance to block the incoming light rays, appears blurred from the eye since the focal plane is not on the SLM and blocks the light stimulation insufficiently. To solve this problem, the aperture-based expanded mask has been used in past studies, however, the excessive large expansion ratio used in this approach leads to over-blocking (occlusion leak). In this work, we build an optimization model by simulating the defocused occlusion mask and determining the effective contribution of the degraded pixels based on the occlusion efficiency of the pixel transmittance. While the non-processed mask cannot provide sufficient occlusion and the aperture-based expanded mask causes occlusion leak, our optimized mask attenuates the intensely bright areas to a proper brightness without incorrectly attenuating surrounding areas that no need to modulation.
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