Based On Digital Image Processing, Laser Marking System

With the development of lasers technology, laser marking technology is widely applied in the field of laser processing, such as electronics industry, auto industry, hardware, labeling technology, aviation industry, instrumentation and advertising signs, etc. Compared with traditional methods (corrosion process, EDM, print, etc), it has the advantages of high efficiency, high-precision, high quality, small heat-affected zone, no pollution, etc. Consequently it is meaningful to research and study the laser marking system.Currently, the main objects of the laser marking are image and font. And the font can be saved as image through the form of conversion. So this paper mainly studies the following issues of the image as the main object of the laser marking.Images are divides into bitmap and vector, although bitmap is widely used, it occupies large space, works inefficient and makes large distortion. Vector occupies a small space, with high marking efficiency and small distortion. But most of vectors rely on AutoCAD and other software, although the vectors are simple, more complex vectors will draw for a long time and the process is very cumbersome.To solve the problems, this paper studies the arithmetic process which can make a bitmap into a vector. The process is divided into two parts: 1.the preprocessing part of the image, it includes color gray, gray-scale transformation, filtering, binarization; 2. the processing part of the image features, it includes edge detection, edge thinning and vector processing. The purpose of the first part is to provide a good initialization environment for the edge detection and the vector processing, and the purpose of the second part is to gain the whole edge of the bitmap, thins the edge width for one pixel, and is able to the vector processing. The system can obtain the coordinate of the edge and control the movement trajectory of the laser according to the coordinate of the edge.According to the shortcomings of controlled modes for laser marking system, the paper puts forward a new mode which components of computer and motion control card. The motion control card if from LeChuang Automation Co., Ltd. it is the high performance multi-axis motion control card MPC07. The function of the card is to realize the two-axis stepper motor control and laser control. The system comes with a feature powerful, rich content of the Windows driver and DLL libraries. The libraries can use support the second development and can shorten development time.This paper focuses on the processing algorithm research of how to make a bitmap image into vector. It studies how to choose the various treatment algorithms according to the image feature. And it makes some revision to Canny operator for some algorithm, so as to improve the extraction of a variety of adaptive edge. Different characteristics of the images need the different image processing algorithms, so the steps of the process include a lot of processing algorithms, the estimation of the algorithm's suitability is judge the effects according to the effect of the algorithm.In order to verify the reliability of the algorithm process, this paper applies object-oriented method of the various image algorithms in each module, applies UML modeling design method to model the entire system, using Visual C + +6.0 to achieve varieties of image coding processing algorithms and system integration, it also contains a friendly user interface for image processing for laser marking software.