基于ART的光学过程层析成像扇束图像重建

Fan Beam Image Reconstruction of Optical Process Tomography Based on Algebra Reconstruction Technique

光学过程层析成像是近几年发展起来的一种新型的光学测量技术 ,它源于医学 CT的基本理论和方法 ,可认为是医学CT技术在工业过程监测领域的自然延伸和发展。然而 ,由于过程层析成像的被测对象为快速变化的工业过程 ,因此 ,其投影数据的数量比医学 CT少得多 ,而实时性则要求更高。利用一种扇束扫描制式的光学传感器有利于提高光学过程层析成像的空间分辨率及测量精度 ,但在这种扫描制式下 ,引用医学 CT的常见图像重建算法 (如数据重排方法、反投影法和滤波反投影法等 )却不适用或难以胜任工业检测的要求。为此提出了一种代数重建技术来提高光学过程层析成像的测量精度和速度。该算法不仅适用于少数投影数据的情况 ,也能使求解过程遍历几乎所有的图像像元 ,因此成像效果好和实时性较高 。

Optical process tomography is a new optical measurement technique which developed recently, and derived from the basic theory and method of medicinal CT, it can be regarded as a nature extend and development of medicinal CT technique in the field of industrial process monitoring. However, becasue the measurement objects of optical process tomography mostly are the industry process which vary rapidly, so the number of projection data of optical tomography will be more limited than medicinal CT, and its temporal demand of imaging is more high. It is favorable to improve the spatial resolution and measurement accuracy by using a fan beam scanning optical sensor, but the familiar image reconstruction algorithms employed in medicinal CT (such as the projections data rearrangement method, LBP and FBP, etc.) can not apply to this sensor, or are competent for industrial measurement. Therefore, a algebra reconstruction technique(ART) is presented to overcome these disadvantages. The ART not only apply to minority projections, also make the solution process ransack the image pixels, so the quality of reconstructed image can be improved, and the imaging temporal consumption is less too, can be used in the engineering application projects.