A Research On Visualization Method Of Metal Detection Based On The Data Of Magnetic Flux Leakage

With the wide application of metal in the world, it has become an indispensable in both industrial production and daily life. However, all the metals are buried in the ground or exposed to various harsh environments, so they have to bear pressure from the internal and external, like the gravity effect of soil, water, air and erosion, corrosion. So the detection of defects or corrosion of the metal work-piece is necessary and of vital importance whether they are using or will be using. Based on metal magnetic flux leakage(MFL) testing data, this paper deeply studied the gray image processing of metal defects to find a optimized processing procedure and implemented curves, gray image, and pseudo-color image of MFL data. Finally we designed the visualization system on matlab platform.This paper first introduced the background and application of the data visualization, and then made a basic study of digital image processing. In order to guarantee good displaying effects of the curve for the subsequent processing, this paper did some pre-processes to the MFL data obtained, including data magnification processing, filtering and noise reduction processing and data deviation upfront and adjusts processing. Then after preprocessing, data directly are generated into a series of MFL curve graph. At the same time in this paper, data are turned into a 0-255 range of gray value after they are preprocessed to get primary gray image. And we utilized three kinds of image interpolation methods applied to primary gray image. After then, this paper used the technology of digital image smoothing, sharpening, and pseudo-color technique processing image enhancement methods to enhance the defect features of visual effect for intuitive and bright defect images. During the procedures of processing, comparison of various processing methods are made to seek the optimal effect. Finally, utilizing the powerful graphics capabilities of matlab, this paper designed the visual system of the metal defect data, basically implemented the curve of metal MFL data, gray image, and pseudo color image of MFL, accomplished the task of data analysis and judgments for detection.According to the characteristics of information which highlighted from the MFL data curve graphics, gray image and pseudo color image of defects, it is not only of great help to professional analysis of MFL data, but also improves the quality and efficiency of MFL data analysis, reduces subjective factors of analysts during the MFL data analysis.