基于HVS算子的自适应清晰度自动调焦评价函数  

A Self-adaptive Clarity Auto Focus Evaluation Function Based on HVS Operator

作　　者：李洪宇[1] 杨帆[1] 谭文斌[2] 李珂[3] 常洪伟[1] LI Hongyu;YANG Fan;TAN Wenbin;LI Ke;CHANG Hongwei(School of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China;School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China;State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China)

机构地区：[1]山东科技大学机械电子工程学院,山东青岛266590 [2]天津商业大学机械工程学院,天津300134 [3]天津大学精密测试技术与仪器国家重点实验室,天津300072

出　　处：《红外技术》2017年第7期632-637,共6页Infrared Technology

基　　金：精密测试技术及仪器国家重点实验室开放基金(PIL1407)

摘　　要：传统梯度类自动调焦评价函数对不同清晰度的序列图像不能兼顾灵敏度高和可调焦范围广两种特性,因此提出了基于人类视觉系统(HVS)算子的自适应清晰度自动调焦评价函数。检测图像各方向上的边缘,计算轻微离焦图像函数值;当图像深度离焦时,划分子区域降低采样率后进行清晰度评价。仿真实验表明本文提出的评价函数,轻微离焦位置灵敏度高,对深度离焦区域图像加均值为0,方差为0.001,0.005,0.01的高斯噪声后函数曲线几乎不变,深度离焦区域内可调焦范围大。该评价函数具有灵敏度高、可调焦范围大、抗噪性能良好等特性,更适合粗精结合的搜索算法使用。The traditional gradient auto-focusing evaluation function can not take into account the high sensitivity and the wide focus range for different clarity sequences.Therefore,a self-adaptive clarity auto-focusing evaluation function based on human visual system(HVS)operator is proposed.Detecting the edge of each direction of the image,calculating the value of the minor defocused image;when the image is depth defocused,the sub-region reduces the sampling rate and then performs the sharpness evaluation.The simulation results show that,the function sensitivity in the mild defocusing position is high,the function curve is almost invariant in the depth defocus region after the Gaussian noise which mean value is0,the variance is0.001,0.005,0.01is added to the image,the wide depth defocus region can be focused.The evaluation function has the characteristics of high sensitivity,large focus range,good anti-noise performance and more suitable for the rough-precise searching algorithm.

关 键 词：自动调焦 评价函数 人类视觉系统算子 清晰度 子区域 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]