OCT图像畸变的消除——相关峰值扫描重定位算法

Recovery of the Distorted OCT Images——the Peak Crosscorrelation Scan Re-registration Algorithm

分析了 OCT系统中某些导致图像畸变的因素 ,提出了相应的补偿算法——“相关峰值扫描重定位算法”。从图像的相关峰值位置函数中 ,将样品本身灰度特征的变化规律和畸变特征用数字滤波的方法分离开来。分析了噪声对相关运算的影响及用灰度门限抑制噪声的措施。讨论了算法的容错性 ,通过对重定位量加以限制 ,避免了严重错位引起的重定位阶跃失真。对算法存在的累积误差等局限性提出了改进建议。给出了畸变图像的恢复实例。

Peak crosscorrelation scan re registration” algorithm aiming at the recovery of the distorted OCT images is proposed in this paper. The image distortion related factors are analysed theoretically. Digital filtering allows the distortion information to be derived from the peak crosscorrelation functions. A gray threshold is set to avoid the influence of the noise in crosscorrelation. To reduce unexpected misregistration induced re registration fault, the maximum value of re registration is limited, as a result the fault tolerance of the algorithm is greatly improved. In addition, the paper also gives the distorted images and the restored ones, together with the suggestions to decrease the cumulating errors of the algorithm.