The Engineering Implementation Of The Algorithm For Fast Positioning In Vision By Arbitrary Angle Rotation

Template matching has not only become a very important technology in the field of modern information procession but also been the basis of some image analyzing technologies. It has been applied in many other fields including: electronic processing, laser cutting, object recognition, shape reconstruction, motion tracking, medical image, character recognition, etc. In engineering applications the template inevitably exists angle rotation with the target image, until now we have not a universal method of rotation invariant. For different applications, the research of the rotation invariant matching has some theoretical and practical value.There are many matching methods for rotated images. But as the target image changed in practical applications some of these methods have some drawbacks such as the speed can not meet the demands, the robustness is not good, inability for arbitrary angle rotations. Through the analysis of some existing algorithms based on the characteristics of the object, the article presents an improved algorithm, the main research contents as follows:1. Several typical template-matching strategies are summarized. Various matching and registration methods for rotated images and their rationales are analyzed and their merits and drawbacks are compared.2. This thesis focuses on the study on an image-matching method that based on the ring projection transformation (RPT). The pixels of the radius is rotation invariant, so I propose the pre-filter and exact filter. Meanwhile, in order to improve the speed, the use of pyramid hierarchical search method to complete the matching process and i use the surface fitting to achieve sub-pixel accuracy.3. The method is realized and applied on the cutting machine. XY axis of the cutting machine position is used as a research platform. And many experiments have been carried out on the platform.Many experiments have been carried out for the proposed method and analysis have been made on its performance of matching speed, matching precision and stability. The experimental results show that the algorithm is arbitrary angle rotation invariant, high speed, rather high matching rate, and it is robust to noise.