一种显微CT系统图像畸变校正方法

A Method of Image Distortion Correction in Micro-CT System

基于透镜耦合的光耦探测器由于其高分辨力、倍率选择多样化的特点,被应用到显微CT系统中.然而,光耦探测器的成像畸变影响了显微CT系统的成像质量.为此提出一种适用于显微CT系统的图像畸变校正方法.建立理想图像和实际畸变图像的多项式函数关系,利用特征点坐标求取畸变系数,并利用畸变系数对图像进行畸变校正.实验结果表明,所提方法能够有效地校正畸变,校正后系统的空间分辨力由原来的8.5μm提升到4.2μm.标准网格板图像校正后网格线的弯曲得到明显改善,网格间距趋于平均,离散程度变小.同时,该畸变校正算法复杂度低,具有较高的实用性.

Lens-coupled X-ray detectors have been applied in X-ray micro-CT system for its high resolution and flexible magnification choice. However,imaging distortion of lens-coupled detector may degrade the imaging quality of micro-CT system. To reduce the image distortion,a correction method is proposed.The polynomial function relationship between the ideal image and the real distortion image is established,and the distortion coefficient is calculated by the coordinates of feature points. Then the distortion image can be corrected by using the distortion coefficient. Experimental results show that the proposed method can effectively correct the image distortion. The spatial resolution of the system is enhanced from 8. 5 μm to 4. 2 μm. The bending of standard grid is smaller and the grid spacing tends to be more equal with a smaller discrete degree after distortion correction. At the same time,the distortion correction algorithm has low complexity and high practicability.