Visual localization is critical to many applications in computer vision and
robotics. To address single-image RGB localization, state-of-the-art
feature-based methods match local descriptors between a query image and a
pre-built 3D model. Recently, deep neural networks have been exploited to
regress the mapping between raw pixels and 3D coordinates in the scene, and
thus the matching is implicitly performed by the forward pass through the
network. However, in a large and ambiguous environment, learning such a
regression task directly can be difficult for a single network. In this work,
we present a new hierarchical scene coordinate network to predict pixel scene
coordinates in a coarse-to-fine manner from a single RGB image. The proposed
method, which is an extension of HSCNet, allows us to train compact models
which scale robustly to large environments. It sets a new state-of-the-art for
single-image localization on the 7-Scenes, 12 Scenes, Cambridge Landmarks
datasets, and the combined indoor scenes.

本文提出了一种新的 Hierarchical Scene Coordinate 网络，可以在一个像素级的场景坐标的预测中，以逐层递进地方式执行粗到细的预测，这种新方法在单图像定位方面表现出较好的性能，并在 7-Scenes，12 Scenes，Cambridge Landmarks 数据集和室内场景数据集上创下了新的最佳表现。