Adaptive dynamic range camera with reflective liquid crystal

Hidetoshi Mannami, Ryusuke Sagawa, Yasuhiro Mukaigawa, Tomio Echigo, Yasushi Yagi

Abstract: Wide dynamic range images (WDRIs) are needed for capturing scenes which include drastic lighting changes. This paper presents a method to widen the dynamic range of a camera by using a reflective liquid crystal. The system consists of a camera and a reflective liquid crystal placed in front of the camera. By controlling the attenuation ratio of the liquid crystal, scene radiance of each pixel is controlled adaptively. After applying the control, the original scene radiance is derived from the attenuation ratio of the liquid crystal and the radiance obtained by the camera. We have implemented a prototype system and conducted experiments in a scene that includes drastic lighting changes. These lighting changes require that we control the radiance of each pixel independently. We show how WDRIs are obtained by calculating the original scene radiance from these results.