A Study Of 3-D Measurement With Moire Contouring Technique

Moire fringe technique is very useful in many field as a means of scaling the 3-D shape of the object, such as in science analysis, industry controlling, biology engineering, biomedicine, material science and so on. It is by virtue of non-contact, nondestructive, high speed and precise measuring. The development of image processing method promotes the performance of measurement system effectively, and enhance the measurement precision of the system. In the recent several years, it has been used widely in both military field and civilian field in some of the developed countries. But its development is too slow in our country. So studying and developing the relative practical application of the Moire fringe is necessary. Firstly, several methods about 3-D measurement with Moire fringe technique are discussed in the dissertation. Then I choose the Moire contouring method to experimentize. At the end of my dissertation, a new way for Moire topology measuring object by a little change of the measuring optical disposal is given. The carrier wave fringe is easy to process, but this method must be together with high quality laser and other instrument which must be precisely located. In this way the error rate of phase demodulation is relatively great. The Moire contouring method is easier than it. The new Moire topology method in the rear part of my dissertation just merges the virtue of the two methods. On the base of acquiring the moire fringe image of the object by the moire contouring measurement system, it is initially processed and with binary conversion, thinning and image reconstruction. The approximate 3-D image is obtained at last. The first stage is include image's gray numbers on average, image enhancing by average filter, part enhancing and enhancing by homeostasis filter. The way in image thinning is a template wrapped-mutiply method, which was acquired by practice over and over. Before thinning, it must be divided and eroded by maths-morphologic. And the way in reconstruction is a kind of special gray inserting method by virtue of the characteristic of the contouring thinning image in my dissertation, in which leverage is used when the image is scanned. First, every pixel in contouring lines is evaluated with height. Then all pixels in the image are evaluated by the inserting value method like lever equilibrium. The homeostasis filter, template thinning and 3-D reconstruction method here is validated effectively. The image processing software is developed with matlab.