Vision Sensor And Its Image Registration Algorithm

As the requirement of the automatization and high speed in the industrialinspection become more and more instant, a new inspection system—vision sensor, has been widely used in the industrial inspection because of its high integration, low cost, low power and easy install. This paper aims at the inspectionproblem of the printings on the electronic components, proposes a feasible design of the vision sensor applied in inspection system and an available imagematching algorithm.Firstly, this paper has a review of the development in the industrial inspection system, analyzes the component of a vision sensor system, and makes a summary of the related image matching algorithms. In order to acquire the bestimage, this paper has designed a simple but available illumination module anda double-mode image acquirement module which supports both of simulate and digital video format. Simultaneously, this paper proposes the corresponding pretreatment algorithms to reduce the influence of the noise and illumination.Secondly, this paper has an analysis of the image matching in the visionsensor inspection system, and introduces the traditional normalized cross correlation matching algorithm (NCC) as the main image matching algorithm of the inspection system. But because this algorithm is more complex and very slow, this paper proposes to make use of the integral image to optimize the algorithm's structure and the Gaussian pyramid hierarchical matching algorithm to improve the search strategy.Thirdly, in allusion to the rotation problem in image matching, this paperhas a retrospection of the past rotation angle detection methods, compares theHough transform detection and ring projection-Zemike moment detection. As the Hough transform can't detect the shift position, this paper introduces a high-speed and effective locating technology, which can reduce the search space gre atly.Lastly, combined with the popular design framework of the vision sensor,the paper proposes an industrial inspection system design based on the high-powered multimedia processor—DM642. This system has a high-speed data processing capacity, which can speed up the algorithm more, and because its bulk is little and function is various, it can be used in the practical industrial inspection.