Background suppression method in TFT-LCD screen automatic optical detection

Abstract

The invention provides a background suppression method in TFT-LCD screen automatic optical detection. The method includes the following steps that firstly, images under different TFT-LCD point screen modes are collected; secondly, a series of high-frequency sub-bands and low-frequency sub-bands are obtained after multi-stage wavelet decomposition of the images; thirdly, each stage of high-frequency sub-bands in multiple directions are subjected to coefficient smoothing, and each stage of low-frequency sub-bands are subjected to contrast enhancement; fourthly, the processed high-frequency sub-bands and the processed low-frequency sub-bands are subjected to wavelet reconstruction, and defect images are obtained after background suppression. The images are subjected to multi-scale multi-resolution decomposition, the decomposed high-frequency sub-bands and the decomposed low-frequency sub-bands are subjected to texture suppression and image enhancement respectively, the contrast of original defects can be kept while background texture is suppressed, and the texture suppression effect is good.

Description

technical field [0001] The invention belongs to the technical field of automatic optical defect detection, and more specifically relates to a background suppression method in automatic optical detection of TFT-LCD screens. Background technique [0002] Due to the characteristics of low power consumption, high definition and low radiation, TFT-LCD (Thin Film Transistor Liquid Crystal Display) has become the current mainstream display device and plays an irreplaceable role in the process of two-dimensional and three-dimensional information transmission. [0003] The production process of TFT-LCD is very complicated, so that various display defects will inevitably occur in the actual preparation process, among which mura defects are the most difficult to detect. The traditional detection method relying on human eyes has many shortcomings, such as high cost, instability and low efficiency. In recent years, machine vision defect detection methods have attracted widespread attent...

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Problems solved by technology

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to provide a background suppression method in the automatic optical inspection of TFT-LCD screens, aiming to solve the problem that the background suppression weakens the defect contrast in the prior art, resulting in poor texture suppression effect. technical problem

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