Digital neutral density filter for moving picture cameras

Schöberl M, Oberdoerster A, Foessel S, Bloss H, Kaup A (2010)

Publication Language: English

Publication Status: Published

Publication Type: Conference contribution, Conference Contribution

Publication year: 2010

Book Volume: 7533

Article Number: 75330L

Event location: San Jose, CA US

ISBN: 9780819479266

DOI: 10.1117/12.838833


Typical image sensors in digital cameras have a fixed sensitivity, and the amount of captured light energy is often controlled by adjusting exposure time and lens aperture. For high end motion imaging these settings are not available as they are used to set motion blur and depth of field, respectively. In many cases a proper exposure is achieved with additional optical filtering, using so called "neutral density" (ND) filters. We propose a digital equivalent of a neutral density filter, which can replace the handling of optical filters for camera systems. It consists of an adjusted sensor readout and in-camera processing of images. Instead of a single long exposure we capture N short exposures. These images are then combined by averaging. The short exposures reduce the sensitivity by a factor of N, while averaging reconstructs motion blur. In addition we also achieve a reduction of both dynamic and fixed pattern noise which leads to an overall increase in dynamic range. The digital ND filter can be used with regular image sensors and does not require hardware modifications. © 2009 Copyright SPIE - The International Society for Optical Engineering.

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How to cite


Schöberl, M., Oberdoerster, A., Foessel, S., Bloss, H., & Kaup, A. (2010). Digital neutral density filter for moving picture cameras. In Proceedings of the Computational Imaging VIII. San Jose, CA, US.


Schöberl, Michael, et al. "Digital neutral density filter for moving picture cameras." Proceedings of the Computational Imaging VIII, San Jose, CA 2010.

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