30 October 1997 Method for detection and visualization of macrodefects in color liquid crystal displays by using Gabor wavelets
Author Affiliations +
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.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hiroki Nakano, Yasuo Yoshida, "Method for detection and visualization of macrodefects in color liquid crystal displays by using Gabor wavelets", Proc. SPIE 3169, Wavelet Applications in Signal and Image Processing V, (30 October 1997); doi: 10.1117/12.279703; https://doi.org/10.1117/12.279703
PROCEEDINGS
12 PAGES


SHARE
KEYWORDS
Wavelets

LCDs

Defect detection

Visualization

Electronic filtering

Inspection

Signal to noise ratio

Back to Top