Tire defect detection method based on singular value decomposition

Abstract

The invention provides a tire defect detection method based on singular value decomposition. A to-be-detected image I containing n pixels is divided to n m*m image blocks; each image block Pi is converted to a column vector ci; column vectors corresponding to all image blocks are used to construct an image block matrix M; through sequentially calculating the ratio of adjacent two singular values, the rank r of the image block matrix M is determined; the former r maximum singular values of the image block matrix M and the corresponding left singular vectors and right singular vectors are used to reconstruct a low-rank approximation matrix Mr of the image block matrix M; each column vector in the low-rank approximation matrix Mr is converted to an image block; all image blocks P<r> are used to reconstruct an approximate image Ir of the to-be-detected image I; hard threshold segmentation is carried out on a residual image I-Ir, a binary image Ib is obtained, and coordinates corresponding to a pixel with a gray value to be one in the image are the defect position. The detection method can position the specific defect position, missed detection and error detection caused by manual operation are avoided, and the defect detection accuracy is improved.

Description

technical field [0001] The invention relates to the technical field of computer vision, in particular to a tire defect detection method based on singular value decomposition. Background technique [0002] Tires are an important part of a car, and its quality directly affects the safety of the vehicle when driving. Usually, a complete tire consists of four regions: crown region, shoulder region, sidewall region and reinforcement region. Affected by factors such as raw materials, processing equipment, and production techniques, a small number of tires may have different types of defects in certain component areas. The defects of tires are mainly concentrated in three parts: sidewall, tire crown and tire shoulder. Common defects include impurities, lap joints and air bubbles. These two types of defects, impurities and laps, will destroy the cord structure inside the tire, resulting in uneven force on the tire and causing a tire blowout; while air bubbles destroy the adhesion...

AI Technical Summary

Problems solved by technology

However, in the actual inspection process, the visual fatigue of workers will cause missed and false detection of tire defects, thus burying hidden dangers to the safety of vehicles

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