一种鱼眼视频全景拼接中的亮度补偿算法  

A luminance compensation method for fisheye video panorama stitching

作　　者：黎吉国 王悦[2] 张新峰 马思伟[2] Jiguo LI1,4,Yue WANG2,Xinfeng ZHANG3,Siwei MA2(1. Institute of Computing Technology, Chinese Academy of Sciences, 100190, China; 2. School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China; 3. School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore; 4. School of Computer and Control Engineering, University of Chinese Academy of Sciences, Beijing 100049, Chin)

机构地区：[1]中国科学院计算技术研究所,北京100190 [2]北京大学信息科学技术学院,北京100871 [3]School of Electrical and Electronic Engineering,Nanyang Technological University,Singapore 639798,Singapore [4]中国科学院大学计算机与控制学院,北京100049

出　　处：《中国科学：信息科学》2018年第3期261-273,共13页Scientia Sinica(Informationis)

基　　金：国家高技术研究发展计划(批准号：2015AA015903)资助项目

摘　　要：随着鱼眼相机逐渐成为全景视频的主要采集设备,面向鱼眼图像的高效全景拼接技术也得到越来越多的关注.为了解决镜头间亮度差异造成的拼接视频质量下降的问题,本文提出了一种基于非均匀采样直方图的亮度补偿算法.该算法根据全景图像在不同纬度空间采样率变化的特点对相邻图像的重叠区域进行非均匀采样,构成统计直方图,通过直方图匹配实现图像间的亮度补偿.此外,考虑到图像亮度分布对拼接图像质量的影响,本文根据重叠区域图像亮度直方图提出了一种新的自适应基准图像选择方法,基于该方法得到的基准图像可以有效提高全景视频的质量,该方法充分考虑了鱼眼镜头的畸变特性,不要求拼接的图像之间精确配准,能够适应不同的光照条件.实验表明,本文提出的算法在保证全景视频质量的同时,有效地降低了亮度补偿的复杂度,从而可以应用于基于鱼眼镜头的全景实时视频拼接系统.The fisheye camera has becoming the most popular panoramic video capturing device.In fact,the stitching for fisheye images has drawn more and more attention.To solve the artifacts resulting from the exposure difference of several cameras,this paper proposes a luminance compensation method based on an uneven sampling histogram.According to the transition of the spatial sampling rate with the latitude＇s increasing in panorama,the proposed method samples the overlapped region of two adjacent images to calculate the histograms,and matches the histograms one by one to balance the luminance.Moreover,in consideration of the influence of luminance distribution to panorama video quality,we present a method for adaptive reference image selection.The selected reference image based on the proposed method can improve the overall quality of the panorama effectively.Due to the consideration of the distortion characteristics of fisheye images,the proposed method does not require an accurate alignment,and it is also well-adapted to luminance variations.Experimental results show that the proposed method can reduce the time complexity for panorama video stitching significantly without obvious quality degeneration,and it is suitable for fisheye lens-based real-time panoramic video stitching.

关 键 词：图像处理 虚拟现实 直方图匹配 鱼眼镜头 视频拼接 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]