Research On Flatness Detection Algorithm For Feature Point Extraction Of Object Surface

Flatness is an important index to detect the appearance defects of objects in industrial production and daily life,which directly affects the quality and beauty of products.However,in terms of construction quality acceptance,most of them still use manual methods for flatness detection,so the detection will have the problems of low efficiency and large error.In this paper,the joints of ceramic tiles paved during decoration acceptance are used as experimental objects.The contents are as follows:(1)Build an image acquisition platform,The inside and outside parameters of the camera are calculated to distortion correction the chessboard image.After obtaining the precise coordinate information of the checkerb,oard lattice is obtained,the camera calibration coefficient is obtained by combining the actual size information of the checkerboard lattice.(2)The key techniques of flatness detection such as line detection,straight correction and flatness calculation are studied.Among them,the line detection is the most important part of the algorithm,and it is found that there is deviation and over-detection between the line and the edge position of the object surface detected by Edge Drawing Lines algorithm.Based on the EDLines algorithm,a straight line correction method is proposed,which is suitable for the straight line detection of ceramic tile joints.Firstly,the linear position is corrected by gradient gravity map,then the polar line is calculated by the point feature matching result,and the final local verification feature region is determined by the joint line detection result.Finally,the linear detection result is checked by the feature similarity of random sampling in the neighborhood to eliminate the mismatched straight line.This method can accurately obtain the straight line information of the ceramic tile joint,which is used to determine whether the joint is straight or not,and greatly improves the accuracy and robustness of the straight line detection of the ceramic ti le joint(3)Three different types of tile joints and four different patterns of tiles were selected for the experiment.During the experiment,the internal parameters are optimized to finally determine the optimal parameters.At the same time,compared with the results of the two existing straight line detection algorithms,the experimental results show that the indicators of this processing result are better than the other two algorithms,and the algorithm is highly robust.