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Proceedings Paper

Method for detection and visualization of macrodefects in color liquid crystal displays by using Gabor wavelets
Author(s): Hiroki Nakano; Yasuo Yoshida
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Paper Abstract

An approach is proposed for detecting macro defects in color LCDs (liquid crystal displays) by using a family of 2D Gabor wavelets. The absolute values of the wavelet coefficients are used to detect macro defects such as periodic or streak patterns. To measure the filter performance, we introduced the improvement rate of the signal-to-noise ratio. The paper also proposes a new method for reconstructing images with enhanced defects by using linear combinations of the real parts of Gabor wavelet coefficients. We obtained the frame bounds of 2D Gabor wavelets which have a discrete sampling step. The reconstructed images can help human evaluators to verify defects. The uniqueness of this method is that not all coefficients are used, but only those that contribute to defect detection. This method is practical in terms of its computational simplicity, and can therefore be used for on- line automatic inspection. Experiments using actual images with defects showed the effectiveness of the method.

Paper Details

Date Published: 30 October 1997
PDF: 12 pages
Proc. SPIE 3169, Wavelet Applications in Signal and Image Processing V, (30 October 1997); doi: 10.1117/12.279703
Show Author Affiliations
Hiroki Nakano, IBM Japan, Ltd. (Japan)
Yasuo Yoshida, Kyoto Institute of Technology (Japan)

Published in SPIE Proceedings Vol. 3169:
Wavelet Applications in Signal and Image Processing V
Akram Aldroubi; Andrew F. Laine; Michael A. Unser, Editor(s)

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