We tackle the problem of large scale visual place recognition, where the task is to quickly and accurately recognize the location of a given query photograph. We present the following three principal contributions. First, we develop a convolutional neural network (CNN) architecture that is trainable in an end-to-end manner directly for the place recognition task. The main component of this architecture, NetVLAD, is a new generalized VLAD layer, inspired by the "Vector of Locally Aggregated Descriptors" image representation commonly used in image retrieval. The layer is readily pluggable into any CNN architecture and amenable to training via backpropagation. Second, we develop a training procedure, based on a new weakly supervised ranking loss, to learn parameters of the architecture in an end-to-end manner from images depicting the same places over time downloaded from Google Street View Time Machine. Finally, we show that the proposed architecture obtains a large improvement in performance over non-learnt image representations as well as significantly outperforms off-the-shelf CNN descriptors on two challenging place recognition benchmarks.

本文提出了一个新的卷积神经网络结构NetVLAD，通过基于新的弱监督排序损失的训练过程，从Google街景中的时间机器下载的图片中，快速和准确地识别所查询照片的位置。同时，该网络结构在两个具有挑战性的地点识别基准测试中优于非学习图像表示和现成卷积神经网络描述符，同时也改善了标准图像检索基准测试上的现有最先进的紧凑图像表示。

NetVLAD：用于弱监督地点识别的CNN架构