• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

计算机工程与科学

• 图形与图像 • 上一篇    下一篇

基于CNN特征加权和区域整合的图像检索

袁晖1,廖开阳1,3,郑元林1,2,曹从军1,3,汤梓伟1,邓轩1   

  1. (1.西安理工大学印刷包装与数字媒体学院,陕西 西安 710048;
    2.陕西省印刷包装工程重点实验室,陕西 西安 710048;
    3.陕西省印刷包装工程技术研究中心,陕西 西安 710048)
     
  • 收稿日期:2018-04-23 修回日期:2018-05-29 出版日期:2019-01-25 发布日期:2019-01-25
  • 基金资助:

    陕西省教育厅科研计划(17JK0990)

Image retrieval based on CNN feature
weighting and region integration

YUAN Hui1,LIAO Kaiyang1,3,ZHENG Yuanlin1,2,CAO Congjun1,3,TANG Ziwei1,DENG Xuan1   

  1. (1.Faculty of Printing,Packaging Engineering and Digital Media Technology,Xi’an University of Technology,Xi’an 710048;
    2.Key Laboratory of Printing and Packaging Engineering of Shaanxi Province,Xi’an 710048;
    3.Printing and Packaging Engineering Technology Research Centre of Shaanxi Province,Xi’an 710048,China)
     
  • Received:2018-04-23 Revised:2018-05-29 Online:2019-01-25 Published:2019-01-25

摘要:

相比传统特征,卷积神经网络提取的特征对图像具有更强的描述能力,其卷积层比全连接层更适合用来检索图像。然而卷积特征是高维特征,若直接用来匹配图像会消耗大量的时间和内存。提出了一种新的改善和整合卷积特征,形成单维特征向量,再将其用于图像匹配的方法。首先,提取最后一个卷积层的三维特征,再对该卷积特征重新加权,突显图像的边缘信息和位置信息;其次,用滑动窗口进行处理,形成多个区域特征向量,再相加整合成全局特征向量;最后,用余弦距离衡量查询图和测试图的相似性得出检索的初始排名,并且用拓展查询方法进行重排得出最终的平均精度均值mAP。分别在Paris6k和Oxford5k数据库以及用100k张图扩展的Paris106k和Oxford105k数据库上进行测试。相对于CroW方法在Paris数据库上获得的mAP性能指标,本文方法提升了约3个百分点;在Oxford数据库上提升了约1个百分点。实验结果表明,新方法提取的全局特征能够更好地描述图像。

关键词: 图像检索, 卷积神经网络, 全局特征, 特征加权, 区域整合

Abstract:

Compared with traditional features, the features extracted by convolutional neural networks have a stronger image description capability, and the  convolutional layer is more suitable for image retrieval than the full connected layer. However, convolution features which are highdimensional consume huge time and memory to do image matching. We propose a new method to improve and integrate convolution features to construct a singledimensional feature vector, and then use it for image matching. Firstly, the 3D feature extracted from the last convolution layer is reweighted to highlight the edge information and location information of the image. Then, we integrate several regional feature vectors which are processed by sliding windows, into a global feature vector. Finally, we get the initial ranking results of the search by using the cosine distance to measure the similarity between the query graph and the test image, and conduct reranking with the extended query method to get the final mean average precision (mAP ). We conduct experiments on the Paris6k and Oxford5k  databases and two extended databases Paris106k and Oxford105k which are extended by100k images. On Paris databases, the proposed method improves the mAP by about 3% compared with the crossdimensional weighting features (CroW) method on Paris. On Oxford databases, our method is about 1%  better than the CroW method. The results show that the global features extracted by our new method can better describe the image.
 

Key words: image retrieval, convolutional neural network, global feature, feature weighting, region integration