文档介绍：摘要
随着数字成像设备的普及,人们对大视角图像有了越来越迫切的需求。获取这种图像有两种方法,第一是用专业设备拍摄,第二是多幅图像拼接,前者几何失真大难以校正,细节不足;后者几何失真小,细节充分,但难以拼接。
本文按照实现一个图像拼接系统所需步骤,首先针对传统基于像素的匹配方法和使用Harris角点法的不足,使用SIFT算法实现了旋转不变、放缩不变,而且能够适应一定光照和视点变化的特征提取。
为获得各幅图像之间重叠部分的关系,需对提出的特征进行匹配,针对传统最近邻查找方法速度缓慢的缺点,提出了采用位置敏感散列算法,提高了匹配速度,并详细讨论了它的原理和实现细节。还将随机选取一致性算法用于错误匹配点对的筛除,解决了匹配结果会有很多错匹配的问题,可以获得完全正确的匹配点对。
通过对成像几何的分析,说明了基于变换矩阵的拼接方法,并指出它的不足和解决办法。为从根本上避免变换矩阵法的不足,在深入研究基于拍摄模型的方法后,建立了球体模型的拼接流程,并使用一种普遍适应的扫描模型,在统一的优化框架下解决了扫描图像拼接问题。还讨论了多种图像插值方法,并对拍摄模型法进行了拓展,使其适应性能更佳,鲁棒性更好。
研究了多种拼接缝消除技术,揭示了在图像间有较大光照或色彩差异的情况下仅采用拼接缝消除技术所带来的不足,针对有较大光照或色彩差异的情况,采用了一种基于直方图的光照和色彩平衡方法,进行统一调整,然后再使用接缝消除技术能得到效果良好的拼接图像。
讨论了全自动图像拼接系统所需要的技术细节和实现方法,实验表明本系统具有很好的鲁棒性和自动拼接能力。
关键词:图像拼接 SIFT算法位置敏感散列算法鲁棒估计球体模型图像融合
ABSTRACT
With the popularity of digital imaging equipment, image with wide field of view are need more and more urgent. There are two methods to get such images, the first is that image with wide field are captured with professional equipment, and the second is get the images with field with the technology of image mosaic. The geometric distortion of the former is large, hard to correlation and has insufficient details, and that of the latter is small and has full details. However the latter is difficult to mosaic.
In this paper, according to the realization step for a Image Stitching System, first we point out the inadequate of traditional pixel-based matching methods and the Harris corner method, use SIFT algorithm to extract interest points which can achieve rotate invariant and scale invariant, and able to adapt to some changes in light and viewpoint.
To obtain the image overlap between parts of the relationship, it is necessary to match the interest point. The traditional method of nearest neighbor search has very slow speed, to e the ing, Locality Sensitive Hashing algorithm is used, and represent detailed discussion of its principles and implementation details. In addition, Random Sample Consensus method is being used to remove mismatching interest point