Papers by Keyword: Line Scanning

Abstract: Since it is difficult to locate license plate quickly and precisely under complicated background and different illumination conditions, therefore, this paper proposes a high-speed and precise approach to solve such kind of problem on the basis of texture analysis and projection method. The approach utilizes both rich textural feature and projective statistical feature of characters in LP region to carry out coarse and fine license plate location. The experiment shows that, under different illumination, car models and background conditions, such approach is proved to be fast, precise and practical.

Abstract: Key technologies of dimensional inspection system of thin sheet part based on machine vision are investigated, and an entire machine vision inspection system is developed. A cad information-based line scanning step adaptive optimization method used for image grabbing of inspected part is proposed. A rectangle lens subpixel edge detection method based on cubic spline interpolation used for edge detection is advanced. A planar contour primitive recognition method based on curvature and HOUGH transform used for image recognition is raised. The inspection accuracy of the inspection system can reach to 1μm, and the inspection time can satisfy the requirements of on-line real-time inspection, so the inspection system is feasible.

Abstract: The fast location is especially important, in the license plate recognition. In this paper, we received the candidate regions by the mathematical morphological operation, and then scanned the middle line of the binarized candidate areas. Determine the plate region using the black-white variations of the pixel in this middle line. This method is based on single line scanning which can reduce the computation time and improve the speed of license plate location.

Abstract: Video processing technology is regarded as a low-cost detection technology in complex environment. Because the placement layer is thin and the surface is complex that causes high detection error and high cost in laser measurement. Two problems must be solved before using it in large-scale composite structures automatic placement. One is to obtain the high-quality and stable image, and the other is to improve efficiency of image processing. In this paper, a method obtaining the high quality placement gap images was studied. It made use of the optical characteristics of composite material’s surface texture. And some parameters were determined by experiments. To reduce the calculation cost of image processing, a placement gap measurement method based on line scanning was also proposed here. The method was effective in our detection experiments on an actual workpiece.