Image-Based Localization Using Hourglass Networks

Iaroslav Melekhov, Juha Ylioinas, Juho Kannala, Esa Rahtu; Proceedings of the IEEE International Conference on Computer Vision (ICCV), 2017, pp. 879-886

In this paper, we propose an encoder-decoder convolutional neural network (CNN) architecture for estimating camera pose (orientation and location) from a single RGB image. The architecture has a hourglass shape consisting of a chain of convolution and up-convolution layers followed by a regression part. The upconvolution layers are introduced to preserve the fine-grained information of the input image. Following the common practice, we train our model in end-to-end manner utilizing transfer learning from large scale classification data. The experiments demonstrate the performance of the approach on data exhibiting different lighting conditions, reflections, and motion blur. The results indicate a clear improvement over the previous state-of-the art even when compared to methods that utilize sequence of test frames instead of a single frame.