Edge Detection Algorithm For Image Measurement And Hough Transform Applied Research

The technology of image measurement is a newly rising technology in the domain of the measurement recent years. It is based on optics, and melts with optoelectronics, computer technology, laser technology, image processing and other modern science technology, so it forms a complex measurement system with those modern technologies. In conclusion, image measurement is a new measurement method, which is used to be means or carrier of detecting and conveying information.The majority of existing image size-measurement systems is based on the linear CCD. The articles, which concerned the practical application that the image measurement is achieved by the planar CCD ,are rare. Aimed at the practical application of the image measurement, this paper emphasizes on the research about the basic methods of the 2-D image geometry size measurement. The image is obtained by the planar CCD. The article researches deeply the key problem of image measurement, namely edge detection algorithm. Hough transform is often used to detect the edge of a given shape curve. This thesis also analyzes in theory the availability of the geometric measurement with Hough transform in image. For a given subject, combined with the Roberts edge detection algorithm, the software is designed to achieve the image size measurement. This experiment proves the availability and validity of this new method. All the results show:Every current detection algorithm has different effect when it's used to deal with image of different gray type and edge type, and difference between those is very clear, each algorithm has it's effective domain and rated object. The solution is to select an algorithm according to the different image and destination of procession. If a method isn't effective, two methods, or even more can be integrated.Hough transform is a coordinate transform to special image forms, it can transform curve or straight line which has been given a figure into a point of transfer space, it also can get special parameters of curve or straight line in this transfer process, and then these parameters can be used to finish measurement of image geometry size.According to the need that some domestic bearing plant want to rapid measure the diameter of the bearing cylindrical roller, this paper make a preview research. Due to the expensive price of high precision optical system and image sensor, the existing laboratory equipment limited the research. In spite of that, the total work achieved the satisfying result and made a strong foundation of the future practical application.