摘要
为提升形貌恢复精度,提出一种高精度的聚焦形貌恢复算法。该方法从序列图像的预处理以及深度值连续化处理角度入手,将零相位滤波与最小二乘拟合法相结合。自行设计了基于巴特沃斯低通的零相位滤波器用以聚焦评价函数曲线的滤波处理,在消除噪声干扰的同时,保持各空间数据点位置不变;根据聚焦评价函数曲线特性,利用基于高斯函数的最小二乘拟合峰值法获取窗口序列的聚焦位置,进一步提高了峰值定位精度;为得到更为连续化的被测物深度信息,采用三次B样条曲面对各个像素点的初始深度值进行插值。实验表明,方法兼具形貌恢复的平滑性及高精度性。
In order to improve shape recovery precision,this paper introduces a high accuracy of 3 D shape recovery algorithm which took cue from reducing the effect of noise and refining the initial depth map and combined zero-phase filer with least squares fitting. To filter the evaluation function of window sequence image,a new Zero-phase Filter is designed based on Butterworth low pass filter,it can remain the position of each dimensional data point constant while eliminating noise,so as to get a more accurate focusing position. According to the properties of focus measure curve,the peak value position of the evaluation function is got by computing the extreme of the least square quadratic curve based on Gaussian function. At last using the cubic surface interpolation,all the more continuous depth of the measurement object is obtained. The experiment shows that the method of this paper both flatness and higher accuracy of shape recovery.
引文
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