Wavelet-based image enhancement for defect detection in thin film transistor liquid crystal display panel

This paper proposes a wavelet-based prepossessing method to improve the detecting capacity of a blob-Mura-defect-detecting algorithm. The non-uniformity of the background region is eliminated by replacing the approximation coefficients with a constant value, and the brightness difference between the background region and defect regions is increased by multiplying the detail coefficients and a weighting factor. The proposed method can perfectly control the detectable defect level by properly selecting the defect detecting level. Experimental results demonstrate that the proposed method can effectively enhance blob-Mura defects in thin film transistor liquid crystal display panels.