High Dynamic Range Camera using Reflective Liquid Crystal

High dynamic range images (HDRIs) are needed for capturing scenes that include drastic lighting changes. This paper presents a method to improve 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 rate of the liquid crystal, the scene radiance for each pixel is adaptively controlled. After the control, the original scene radiance is derived from the attenuation rate of the liquid crystal and the radiance obtained by the camera. A prototype system has been developed and tested for a scene that includes drastic lighting changes. The radiance of each pixel was independently controlled and the HDRIs were obtained by calculating the original scene radiance from these results.

[1]  Shree K. Nayar,et al.  Radiometric self calibration , 1999, Proceedings. 1999 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (Cat. No PR00149).

[2]  Shree K. Nayar,et al.  Programmable imaging using a digital micromirror array , 2004, Proceedings of the 2004 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2004. CVPR 2004..

[3]  Shree K. Nayar,et al.  High dynamic range imaging: spatially varying pixel exposures , 2000, Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662).

[4]  Richard Szeliski,et al.  High dynamic range video , 2003, ACM Trans. Graph..

[5]  B. C. Madden,et al.  Extended Intensity Range Imaging , 1993 .

[6]  Narendra Ahuja,et al.  Active Aperture Control and Sensor Modulation for Flexible Imaging , 2007, 2007 IEEE Conference on Computer Vision and Pattern Recognition.

[7]  Shree K. Nayar,et al.  Assorted pixels: multi-sampled imaging with structural models , 2002, ECCV.

[8]  Steve Mann,et al.  ON BEING `UNDIGITAL' WITH DIGITAL CAMERAS: EXTENDING DYNAMIC RANGE BY COMBINING DIFFERENTLY EXPOSED PICTURES , 1995 .

[9]  Jitendra Malik,et al.  Recovering high dynamic range radiance maps from photographs , 1997, SIGGRAPH '08.

[10]  Shree K. Nayar,et al.  Adaptive dynamic range imaging: optical control of pixel exposures over space and time , 2003, Proceedings Ninth IEEE International Conference on Computer Vision.