低空动态成像位移矢量探测方法

Displacement Vector Detection Method for Low Altitude Dynamic Imaging

为补偿像移、提高影像的质量，需要准确探测影像间的像平面位移矢量。在给出星载相机像移矢量测量常用的联合变换相关基本原理的基础上，提出一种改进的联合变换相关的方法。提出改进的适用于低空影像的自反馈模糊边缘检测方法，以实现输入图像预处理；通过消除0级衍射峰，以质心法提取互相关峰的坐标，实现互相关峰高精度探测。利用仿真和真实低空成像实验对该方法的测量精度和性能进行了分析。仿真表明，该方法对于运动模糊在0～10 pixel范围内，高斯噪声小于等于0．002时，影像间像位移在0～20 pixel时，探测精度可控制在0．03 pixel以内。真实实验进一步表明，本文方法像移测量精度可达到0．2 pixel。该方法能够高精度、稳健地探测低空影像的像位移矢量。

To compensate the image motion and improve the image quality, it is necessary to accurately detect thedisplacement vector between images. Based on the principle of image motion vector measurement with jointtransform correlator, an improved method is proposed. To detect the edges of low altitude images, the improvedself-feedback fuzzy edge detection method is presented to realize the input image preprocessing. By eliminating the0th diffraction peak, the coordinates of relative correlation peaks are extracted with centroid method, and the high-precision detection of relative correlation peaks is achieved. The measurement accuracy and performance of proposedtechniques are analyzed with simulation test and real low imaging experiments. Simulation tests show that thedetection accuracy can be controlled within 0.03 pixel, when motion blur in the range of 0-10 pixel, Gaussian noiseis less than 0. 002 and the displacement between image in 0-20 pixel. Experimental results further show that themeasurement accuracy of the proposed method reaches 0.2 pixel, and it can detect the image displacement vector oflow altitude images with high accuracy and robustness.