用数字图像相关法测量线阵CCD的象元位置

Measuring the Positions of Linear Array CCD's Elements by Means of Digital Image Correlation

本文研究了应用数字图像相关法测量线阵CCD器件各象元相对位置的方法。通过实际的CCD象元图像,对各种相关度量法的匹配精度和抗干扰能力进行了分析对比,选出了适当的相关度量法。为了解决匹配速度问题.本文介绍了SSDA法在本系统中的应用,对其门限选择问题进行了研究并提出了确定门限的方法。文中还提出了一种两级模板寻优的快速匹配方法。在硬件方面,设计了TMS320C25加速处理板与主机构成主从式高速处理系统。

In this paper, the digital image correlation tecniques are investigated for measuring the positions of the CCD elements. Using the real element images, the accuracy and noise immunity of several similarity measures are analyzed, and the proper similarity measures are find out, which have the matching accuracy of 1 pixel. The fast matching algorithms and the hardwares are used to improve the mathching efficeiency. The SSDA method is introduced to our measuring system, and its problem of the choice of the thresholds is investigated and solved. Another fast matching approach called Two-stagge-Template-optimizing Image Matching is put forward, which has no problems of the threshold choosing and has constant mathching speed. In the aspect of hardware, an accelerating card using TMS320C25 digital signal processor is designed to configurate a host/coprecessor high -speed system with the host computer.