Study On Vickers Hardness Testing Method Based On Image Processing Techniques

This topic analyzes the situation of Vickers hardness measurement at home and abroad . According to the measure theory and features of Vickers hardness, this topic designs a project of Vickers hardness measurement basing on image processing techniques. Using CCD image processing techniques, this project can measure objectively. Meanwhile, it can eliminate artificial measure error and improve the accuracy and repetition of the measurement.This topic elaborates on the design process of the Vickers depression measuring system, chooses appropriate instruments, such as light source, shot, optical device, camera, and capture board and so on. Using self-adapting threshold value algorithm, this topic calculates the optimal threshold value of the filmed Vickers depression image. At the same time, this topic deals the depression image with image binaryzation method and edge measurement, fittings the edge straight line with the least squares method. Then this topic gets the diagonal line of Vickers impress and the Vichers hardness of this material. The whole measurement system is compiled with VC++. Experiment shows that the project is accurate and feasible, the structure is suitable and the performance is reliable. All the technique qualifications are up to the requirements of the project.