The image quality in a CIS chip is inferior to that of the CCD mainly because the random noise, which is very difficult to be suppressed in analog circuits, especially in submicron process. The popular high quality random noise suppression algorithms are too complex to be used in a color CIS chip. Besides the random noise, the defect pixels are more difficult to avoid, especially in high resolution CIS system. Therefore, a novel spacial adaptive noise suppression algorithm, which combines the defect pixel correction function, is presented. The spatially adaptive defect correction and noise suppression algorithm consists of defect pixel detector, defect value corrector, image detail estimator, and two configurable Gaussion masks to deal with different complex level image region. With a fast and effective performance, cross mask and 25-in sorting methods are applied to the defect detector and detail estimator circuits. With good PSNR and visual quality results and much less hardware cost, the proposed method can be practically used in a CIS chip or other camera systems.

Date Published: 6 August 2009
PDF: 6 pages
Proc. SPIE 7384, International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Imaging Detectors and Applications, 73842V (6 August 2009); doi: 10.1117/12.836651

Published in SPIE Proceedings Vol. 7384:
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Imaging Detectors and Applications
Kun Zhang; Xiang-jun Wang; Guang-jun Zhang; Ke-cong Ai, Editor(s)