电容层析成像（electrical capacitance tomography，ECT）图像重构算法所重建的图像存在边缘不清晰，成像精度低的问题，很容易误判不同介质的交界面，而截面含水率计算的准确度依赖于对重构图像的二值化分割的准确度。该文通过分析全局阈值分割算法的不足，提出了结合模拟退火算法的局部阈值分割算法。为验证算法的有效性，对层流、中心流、环状流的重构图像进行局部最优阈值分割，并进行截面含水率的计算，通过与全局阈值分割算法进行对比，证明了采用局部阈值分割算法进行截面含水率的计算有相对较高的准确率。此外，考虑到ECT系统本身存在非线性误差，通过结合局部最优阈值分割算法，采用一种考虑ECT非线性误差的图像阈值分割算法。通过与全局阈值分割算法和不考虑非线性误差的局部阈值分割算法进行对比，结果表明考虑ECT非线性误差的局部最优阈值分割算法进行截面含水率的计算具有相对较高的准确率。 The image reconstructed by ECT image reconstruction algorithm has the problems of unclear edge and low imaging accuracy. It is easy to misjudge the interface of different mediums, and the accuracy of cross-section water content calculation depends on the accuracy of binary segmentation of the reconstructed image. Therefore, by analyzing the shortcomings of the global threshold segmentation algorithm, we propose a local threshold segmentation algorithm combined with simulated annealing algorithm. In order to verify the effectiveness, the reconstructed images of laminar flow, central flow, annular flow are segmented by local optimal threshold, and the cross-section water content is calculated. By comparing with the global threshold segmentation algorithm, it is proved that the local threshold segmentation algorithm has a relatively higher accuracy in calculating the section water content. In addition, considering the nonlinear error of ECT system, an image threshold segmentation algorithm considering the nonlinear error of ECT is adopted by combining with the local threshold segmentation algorithm. Comparing the global threshold segmentation algorithm and local threshold segmentation algorithm without considering nonlinear error, shows that the local threshold segmentation algorithm considering ECT nonlinear error has a relatively higher accuracy in the calculation of cross-section water content. 电容层析成像 截面含水率 局部阈值分割 ECT非线性误差 最优化算法 electrical capacitance tomography cross-section water content local threshold segmentation ECT nonlinear error optimal algorithm 参考文献 RASEL R KTEIXEIRA F L , MARASHDEH Q M . Progress in real-time capacitance tomography of multiphase flows based on the maxwell-wagner-sillars effect [C]// 2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) . Glasgow : IEEE , 2021 : 1 - 5 . Progress in real-time capacitance tomography of multiphase flows based on the maxwell-wagner-sillars effect RASEL R K , STRAITON B , MARASHDEH Q , et al . 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