Open AccessAnalog image contouring using a twisted-nematic liquid-crystal display
Author(s) -
Jorge L. Flores,
José A. Ferrari,
Javier A. Ramos,
Julia R. Alonso,
Ariel Fernández
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.019163
Subject(s) - polarizer , liquid crystal , optics , contouring , liquid crystal display , spectrum analyzer , polarization (electrochemistry) , materials science , image processing , physics , computer science , birefringence , artificial intelligence , image (mathematics) , computer graphics (images) , chemistry
We present a novel image contouring method based on the polarization features of the twisted-nematic liquid-crystal displays (TN-LCDs). TN-LCDs are manufactured to work between a crossed polarizer-analyzer pair. When the analyzer is at 45 deg (instead of 90 deg) with respect to the polarizer, one obtains an optically processed image with pronounced outlines (dark contours) at middle intensity, i.e., the borders between illuminated and dark areas are enhanced. The proposed method is quite robust and does not require precise alignment or coherent illumination. Since it does not involve numerical processing, it could be useful for contouring large images in real-time, which presents potential applications in medical and biological imaging. Validation experiments are presented.