基于预条件共轭梯度法的混凝土层析成像

Concrete Computerized Tomography Based on Preconditioned Conjugate Gradient Method

根据常规图像重建的共轭梯度迭代算法,提出一种预条件共轭梯度法。用一种新的预条件子M来改善系数矩阵的条件数,结合一般的共轭梯度法,导出预条件共轭梯度法。实验结果表明,预条件共轭梯度算法比共轭梯度算法具有更好的CT重建效果和消噪能力,可提高计算的精度和图像的重建质量。

This paper presents a Preconditioned Conjugate Gradient（PCG） method from a view of probability for concrete image reconstruction. This method presents a class of conjugate gradient methods with a new conjugacy condition which is proved under suitable conditions, and combines with a general Conjugate Gradient（CG）method, which lead to PCG method. Computer simulation and concrete model of ultrasonic computerized tomography show that PCG method is more effective to improve the accuracy of computation and the quality of image reconstruction on concrete than the conjugate gradient method.