自动焦度计图像及图像处理系统研究

Imaging and Image Processing System of Auto Lensmeter

为了提高自动焦度计的测量精度,提出一种新的测量图像.该图像在原有4点测量图像的基础上,增加了12个测量点,建立了16点数学模型并推导了镜片相关参数的计算方法.该算法将16个点分为4组进行计算,并取各组计算结果的平均值作为最终测量结果.根据16点数学模型的算法要求,设计了以ARM技术和面阵CCD为核心的测量系统及16点图像二值化处理的算法.实验数据表明,该测量系统的技术指标已达到国家相关检验标准;该系统在测量精度及稳定性上都优于原有的基于4点测量图像的自动焦度计.

A new design of imaging and image processing system for auto lensmeter was presented to improve the measuring accuracy of the equipment. Compared with the traditional design which has 4 imaging points, the new method increased 12 points. A mathematical model based on the 16 testing points was established. By dividing the 16 testing points into 4 groups, the final measurement result was the average of the 4 groups ＇ testing values. According to the calculation method of the model, a measuring system based on ARM and CCD was designed, and the image binarization algorithm was realized. The experiment results show that the new design of auto lensmeter has been qualified to the related national standard. Furthermore, the results also imply that the new design is better than the old one on measurement accuracy and stability.