用傅里叶相移特性估计位移

提出了一种从频率域出发,估计出运动物体在空间域位移的算法。利用傅里叶变换的自配准性质和位移特性,用极坐标形式下连续图像相位谱的差直接估计运动目标的位移。与传统的寻找迪拉克峰值的方法相比,本方法无需重新变换回空间域,从而节省了处理时间,具有更好的实时性。实验证明,这种先求出相位谱的差,再用其周期数来估计位移的算法简单明了,其分辨能力不低于一个像素。该理论可以应用于图像跟踪和图像后期处理中。

Translation estimation by phase-shifting of Fourier transform

An algorithm which is used to estimate the translation of a moving object in spatial domain according to its Fourier transform spectrum is proposed in the paper. Based on shift theorem of Fourier transform and auto-registration, the algorithm directly estimates the translation with the phase spectrum difference of continuous images of a moving object in a polar coordinate system. Compared with traditional algorithm which has to search Direc peak, this method needs not transform spectrum to spatial domain after calculation, which reduces processing time. Experiments prove that since the results of the algorithm are shown by periods, it can give the displacement of a moving target with a resolution less than 1 pixel. It is also proved that the algorithm is simple and fast and can be used in image tracking and post- image processing.