Automatic Defect Inspection for LCDs Using Singular Value Decomposition

The purpose of this study aims at the use of machine vision for automatic surface inspection, in which defects are embedded in homogenously LCDs textured surfaces. The proposed method does not rely on local features of textures. It is based on a global image reconstruction scheme using the singular value decomposition (SVD). The singular values on the decomposed diagonal matrix represent different degrees of detail in the textured surface. By selecting proper singular values on the diagonal matrix and reconstructing the matrix with the selected singular values, we can eliminate regular, periodical patterns of the textured image, and preserve the anomalies in the restored image. Experimental results have shown that the proposed method is effective for detecting micro-defects in LCDs surfaces.