【作者】 艾维平；

【导师】 马跃洲；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2007， 硕士

【摘要】 平板探测器X射线实时成像检测是一项极有发展前途的现代射线检测技术，但是它在国内目前尚处于起步阶段，相关的研究和应用还比较少。本文以开发新型的X射线数字实时成像检测系统为目的，以美国GE公司DXR250RT平板探测器为对象，在深入研究其内部构造、成像原理、工作方式以及平板探测器成像系统的噪声来源及其抑制方法的基础上，开发了集图像采集、显示、图像处理和运动控制功能于一体的系统软件。论文研究了X射线成像检测的技术基础。主要内容包括X射线的产生、性质及它与物质相互作用时发生的各种效应；通过分析X射线穿过物质后衰减规律和射线探伤的原理，探讨了射线成像灵敏度的影响因素，并提出相应有效的抑制措施。通过分析DXR250RT平板探测器的内部构造、成像原理和成像系统各部分功能，对其检测系统的工作方式、噪声来源进行了深入的研究。在此基础上提出了基于最小二乘法的滤波措施；详细介绍了流行的数字成像质量的评价指标(即调制传递函数、噪声功率谱、检测量子效率和噪声等价量子数)的定义和测量方法。深入研究平板探测器数字图像采集的工作流程和计算机数字图像显示原理后，在Windows XP平台上，利用Visual C++6.0开发了基于DXR250RT命令处理器的图像采集及显示软件。针对X射线数字图像的特点，研究了X射线数字图像的灰度变换、平滑和边缘锐化等多种图像处理算法，以进一步消除噪声提高对比度并突出图像细节，开发的X射线数字图像处理软件能够完成多种处理功能。当大型构件尺寸超出平板探测器的有效检测面积时，平板探测器需要在一定范围内能够实现运动扫描，为此开发了基于计算机控制方式的运动控制系统，从而拓宽了平板探测器成像系统的应用范围。更多还原

【Abstract】 Flat panel detector measures to be one of promising techniques in modern radiation testing for its real-time digital imaging and diagnosis. But the interrelated research and application of flat-panel detector are few at home. For developing a late-model X-ray digital real-time imaging inspection system, the intramural structure, imaging principle and working mode of DXR250RT flat panel detector from GE Company are researched in this dissertation. Besides noise source and restraining methods of imaging system based on DXR250RT. It was developed that the software integrated image capturing, image processing and movement control function.The technology base of X-ray imaging inspection was studied in this paper. The main contents include bringing and characters of X-ray, and offects when it acts to substance. After the attenuation law of X-ray which perforates substance and X-ray defects testing principle were analyzed. Influence factors of X-ray imaging sensitivity was disussed and effective restraining measures were brought forward.Working mode and noise source of imaging inspection system were researched further after the intramural structure, imaging principle of DXR250RT and system functions were analyzed. On the base, the Restriction Minimum Two-Multiply Filter was brought. Some popular estimate parameters to digital imaging quality were introduced. Such as MTF, NPS, DEQ and NEQ.After working flow and digital image display principle on computer were studied, image capturing and display software were developed based on command processor by Visual C++6.0 on Windows XP platform. According to features of X-ray digital images, many kinds of image-processing algorithm including grey-level transform, smoothing and sharpening were studied. Image-processing software was designed can also accomplish functions. For example,suppressing noise, stretching contrast and stressing details. FPD requires scan in a two dimensional plane when the workpiece size exceed its inspection area. For the reason, the movement control system was designed based on computer mode.更多还原