FPGA-based distortion correction for laser spot inspection system

摘要：

This paper focuses on the correction of radial distortion in the laser spot vision inspection system, which is the main cause for the inaccuracy of measurement results. An efficient circuit architecture using a low cost FPGA (field programmable gate array) and a hardware look-up table for distortion correction is presented. The polynomial fitting formula between the pixels in the distorted image and those in the corrected one will be calculated under software circumstance, then converted into the addresses of FLASH memory as a look-up table. By access to FLASH memory instead of complex arithmetic, FPGA can obtain the spatial correction data, according to which the gray scale can be gained and corrected with a nearest-neighbor principle. Experiment results illuminate the relative distortion declines from 23.88％ to approximately 1％, and the average error of the spot center is within 1mm. The reduction of distortion error facilitates the application of the short-focus and wide-angle lenses, and therefore promotes the development of portable and miniaturized instruments.

关键词： Vision inspection laser spot FPGA distortion correction look-up table

作者: Zhaoxia Zhang Yang Han Xiaodong Chen Daoyin Yu

作者单位: College of Precision Instrument & Opto-electronic Engineering, Tianjin University, Key Laboratoryof College of Precision Instrument & Opto-electronic Engineering, Tianjin University, Key Laboratory of

会议类型: 国际会议

会议名称: 第五届仪器科学与技术国际学术会议(ISIST 2008)Fifth International Symposium on Instrmentation Science and Technology

会议地点: 沈阳

会议语种:英文

页码: 1-8

在线出版日期: 2008-09-15（万方平台首次上网日期，不代表论文的发表时间）