节点文献
ET重建图像质量评估研究
Research on ET Reconstructed Image Evaluation
【作者】 钱相臣；
【导师】 王超；
【作者基本信息】 天津大学 ， 检测技术与自动化装置， 2007， 硕士
【摘要】 电学层析成像(Electrical Tomography,简称ET)技术是上世纪80年代发展起来的一种新型测量技术。该技术具有结构简单、成本低廉、非侵入及无辐射等优点,在工业测量和生物医学工程领域具有广阔的应用前景。经过二十余年的发展,ET技术取得了很大的进步,但由于其反问题求解存在严重的不适定性,使得重建图像的质量并不理想,图像分辨力较差。作为ET技术的最终归宿,重建图像质量的优劣体现着ET系统硬件和软件上的进步程度。虽然已经有很多学者在ET重建图像质量评估方法的研究上做了大量的工作,但还停留在对二值图像进行单参数评估的阶段。针对目前存在的问题,本课题从ET技术的原理出发,研究了重建图像区别于其它数字图像的特点,提出了多参数、定量的ET重建图像质量评估方法,并编写了ET重建图像质量评估软件。主要研究工作如下:1. ET重建图像特点分析从ET技术原理出发,通过对ET反问题求解的病态性、正问题的求解方法、ET中存在的软场特性、测量电极的配置等问题,以及不同重建算法特点的分析,归纳出了ET重建图像所独有的特点。2. ET重建图像质量评估方法研究结合ET重建图像的特点,提出了多参数、定量的评估ET重建图像质量的方法。评估方法包括三类参数:表征图像本身属性的参数;刻画图像特点的特征;反映两幅图像之间相似程度的参数。经过实验证明,本文提出的评估ET重建图像质量的方法是可行的。3. ET重建图像质量评估软件设计应用Visual Basic.NET编程环境设计了基于32位Windows平台的ET重建图像质量评估软件。本软件实现了所有评估参数的计算。并且具有操作界面友好,操作简单以及功能齐全的特点,完全可以用于实际应用。
【Abstract】 Electrical Tomography (ET) is a new measurement technique developed in 1980th. Due to the advantages of simple structure, low cost, non-intrusive and non-radiant, ET technique has wide prospect for application in the field of industrical measurement and biomedical engineering.Although great progress has been made in ET technique in the past two decades, good images in terms of high quality and distinguishability have not been achieved because the ill-conditioned property of inverse problem. As the final product of ET technology, reconstructed image embodies the progress of the hardware and software of ET system. Much work has been done by researchers, but the state of arts still limited in the bounds of single-parameter evaluation of binary images. To solve the problems existed, the unique characteristics of ET reconstructed image are studied by analyzing the basic principle of ET technique, and thorough achievements have been conducted on a multi-parameter, quantitative evaluation method and design of evaluation software in this thesis. The main work and results are as follows.1. Analysis of ET Reconstructed Image CharacteristicsBased on the basic principle of ET, the unique characteristics of ET images are gentralized by analyzing the ill-conditioned inverse problem, solution of forward problem, the soft field character, placement configuration of electrodes etc.2. Research on Quality Evaluation of ET Reconstructed ImageIn terms of the characteristics of ET reconstructed image, a quantitative multi-parameter evaluation method is presented. There are three kinds of parameters for the evaluation method: basic attributes, unique characteristics of ET image and the parameters reflect the similarity of two images. The feasibility of the method is testified by using of well designed experiments.3. Software Design for Image Quality EvaluationSoftware for ET reconstructed image evaluation is designed based on 32-bit Windows platform and Visual Basic.NET programming environment. The evaluation method that presented in the thesis is completely implemented, and the interface is friendly and easy to be operated.