Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2010, Article ID 197194, 30 pages doi: Research Article Automatic Level Control for Video Cameras towards HDR Techniques Sascha Cvetkovic,1 Helios Jellema,1 and Peter H. N. de With2, 3 1 Bosch Security Systems, 5616 LW Eindhoven, The Netherlands of Electrical Engineering, University of Technology Eindhoven, 5600 MB Eindhoven, The Netherlands 3 CycloMedia Technology, 4181 AE Waardenburg, The Netherlands 2 Department Correspondence should be addressed to Sascha Cvetkovic, Received 30 March 2010; Revised 15 November 2010; Accepted 30 November 2010 Academic Editor: Sebastiano Battiato Copyright © 2010 Sascha Cvetkovic et al. This is an open. | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2010 Article ID 197194 30 pages doi 2010 197194 Research Article Automatic Level Control for Video Cameras towards HDR Techniques Sascha Cvetkovic 1 Helios Jellema 1 and Peter H. N. de With2 3 1 Bosch Security Systems 5616 LWEindhoven The Netherlands 2 Department of Electrical Engineering University of Technology Eindhoven 5600 MB Eindhoven The Netherlands 3 CycloMedia Technology 4181 AE Waardenburg The Netherlands Correspondence should be addressed to Sascha Cvetkovic Received 30 March 2010 Revised 15 November 2010 Accepted 30 November 2010 Academic Editor Sebastiano Battiato Copyright 2010 Sascha Cvetkovic et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. We give a comprehensive overview of the complete exposure processing chain for video cameras. For each step of the automatic exposure algorithm we discuss some classical solutions and propose their improvements or give new alternatives. We start by explaining exposure metering methods describing types of signals that are used as the scene content descriptors as well as means to utilize these descriptors. We also discuss different exposure control types used for the control of lens integration time of the sensor and gain control such as a PID control precalculated control based on the camera response function and propose a new recursive control type that matches the underlying image formation model. Then a description of commonly used serial control strategy for lens sensor exposure time and gain is presented followed by a proposal of a new parallel control solution that integrates well with tone mapping and enhancement part of the image pipeline. Parallel control strategy enables faster and smoother control and facilitates .
