测绘通报 ›› 2023, Vol. 0 ›› Issue (4): 93-98.doi: 10.13474/j.cnki.11-2246.2023.0110

• 无人机测绘技术应用推广 • 上一篇    下一篇

图索引结构词袋模型的无人机影像匹配对检索

刘思康1, 郭丙轩1, 姜三2, 鄢茂胜1   

  1. 1. 武汉大学测绘遥感信息工程国家重点实验, 湖北 武汉 430079;
    2. 中国地质大学(武汉), 湖北 武汉 430074
  • 收稿日期:2022-05-11 发布日期:2023-04-25
  • 通讯作者: 郭丙轩。E-mail:mobilemap@163.com
  • 作者简介:刘思康(1997—),男,硕士生,研究方向为实景三维重建。E-mail:2020206190043@whu.edu.cn
  • 基金资助:
    国家自然科学基金重大研究计划(B2021061516)

Matching pair retrieval method of UAV images based on the graph structure bag of words model

LIU Sikang1, GUO Bingxuan1, JIANG San2, YAN Maosheng1   

  1. 1. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China;
    2. School of Computer Science, China University of Geosciences, Wuhan 430074, China
  • Received:2022-05-11 Published:2023-04-25

摘要: 无人机影像匹配对选择是提升影像匹配效率和三维重建稳健性的关键技术。针对经典树状索引结构词袋模型存在查找单词效率低、影像相似度计算精度低、时间复杂度高的问题,本文设计了导航小世界(NSW)图索引结构和TF-IDF-Match4算法,并提出了一种基于图索引结构词袋模型(GSBoW)的无人机影像匹配对检索方法。首先,利用SIFT GPU算法提取无人机影像特征,并通过分层K-means进行特征描述子集合聚类生成单词;然后,利用NSW索引结构进行单词组织,即从单词集合中随机挑选单词作为顶点插入图中,同时找到最邻近M个顶点建立顶点之间的边连接关系,直至所有单词插入结束;最后,在GPU端利用NSW索引结构进行最邻近单词检索,并使用TF-IDF-Match4算法计算查询影像与数据集影像的相似度,实现无人机影像的匹配对选择。本文利用3组大规模航空无人机影像进行试验,并与Colmap和DBoW的词袋模型算法进行对比。结果表明,与Colmap和DBoW词袋模型相比,本文的GSBoW检索算法效率分别提高了45和18倍,且显著提高了初始匹配精度。本文方法提供的影像匹配对能够保证三维重建获得更高的精度。

关键词: 影像检索, 词汇树, 导航小世界, TF-IDF-Match4加权, GPU, 最邻近查找

Abstract: Matching pair selection is a key technology to improve feature matching efficiency and 3D reconstruction reliability of UAV images. However, the classical tree index structure word bag model has low efficiency in finding words, low precision in similarity calculation, and high time cost in image retrieval. This study designs the navigation small world (NSW) graph index structure and TF-IDF-Match4 algorithm, and proposes matching pair retrieval method based on the Graph Structure Bag of Words (GSBoW) model. Firstly, the SIFT GPU algorithm is used to extract features of UAV images, which are used to generate visual words through hierarchical K-means clustering. Secondly, visual words are indexed by using a NSW graph index structure, which is achieved by iteratively selecting a random word and inserting it into the NSW graph, and searching its M nearest vertices that are used to build the edge connection. Finally, the NSW graph structure is implemented on GPU for nearest word searching, and match pair selection is achieved by an efficient algorithm, termed TF-IDF-Match4, for the calculation image similarity scores. The experiments are carried out using three large-scale UAV datasets and compared with the bag of words model algorithms in Colmap and DBoW. The results show that the proposed match pair retrieval algorithm can respectively achieve the speed up ratio of 45 and 18 times compared with Colmap and DBoW, which is provided matching pairs for higher accurate 3D reconstruction.

Key words: image retrieval, vocabulary tree, navigation small world, TF-IDF-Match4 weighted, GPU, the nearest neighbor search

中图分类号: