一种用于数码视频相机实时自动聚焦算法.pdf

第 35 卷第 8 期 光电工程 Vol.35, No.8 2008 年 8 月 Opto-Electronic Engineering Aug, 2008 文章编号：1003-501X(2008)08-0139-06 一种用于数码视频相机的实时自动聚焦算法 盛 云，秦亚杰，洪志良 ( 复旦大学 专用集成电路与系统国家重点实验室，上海 201203 ) 摘要：本文针对数码视频相机的噪声大，主体位置不确定性及实时性要求高等特点，详细讨论了传统自动对焦算 法的缺陷并提出了一种新的自动对焦算法。该算法采用一种新的可有效抑制高频噪声的对焦量函数——高斯一阶 导数(FDOG)来正确评价图像对焦趋势；支持最近主体优先的感兴趣区域自动选择，使得系统可以自动找到主体所 在位置进行对焦；结合爬山法，二叉有哪些信誉好的足球投注网站和插值拟合进行对焦有哪些信誉好的足球投注网站，相比传统的两段爬山法，有哪些信誉好的足球投注网站效率提高了 40%； 通过对聚焦后的图像进行监视，支持视频模式下的动态自动对焦。该算法在一个数码视频相机平台上实现，实验 结果验证了算法的优点，适用于高性能数码视频相机。 关键词： 自动对焦；数码视频相机；高斯一阶导数；最近主体优先；感兴趣区域；二叉有哪些信誉好的足球投注网站 中图分类号：TN492, TN911.73 文献标志码：A Real-time Auto-focusing Algorithm for Digital Video Camera SHENG Yun，QIN Ya-jie，HONG Zhi-liang ( State Key Lab of ASIC and System, Fudan University, Shanghai 201203, China ) Abstract :Digital video camera has the properties of large noise, uncertain location of main body and high requirement of real-time. The disadvantages of traditional auto-focusing algorithms were discussed in detail and a new auto-focusing algorithm was proposed. A novel focus measure filter called First Derivative of Gaussian (FDOG) was developed to estimate the degree of focusing correctly by the suppressing high frequency noise. To enable the auto-focusing system to focus on the exact main body, an automatic region-of-interest selection strategy based on the principle of nearest-subject-priority was adopted. Furthermore, combined with mountain-climbing search, binary search and quadratic interpolation, the proposed real-time search strategy greatly reduces the convergence time by about 40%, which enables the video camera to fast focus. The proposed algor