Reviews: Geometry-Aware Recurrent Neural Networks for Active Visual Recognition

The paper proposes a method for reconstructing, segmenting and recognizing object instances in cluttered scenes in an active vision context, i.e. in situations where the camera can be moved actively by an agent, for instance a robot. Active vision is investigated actively in the recent past, and there seems to be a convergence between different communities, which start to develop similar methodologies for different objectives: (i) research in agent control, in particular with POMDP/Deep-RL, tackles realistic settings requiring visual recognition and includes geometry in its research, and (ii) research in vision/object recognition discovered Deep-RL to tackle active vision and creates neural/differentiable formulations of geometry based methods. The proposed method belongs to the second category and solves the problem with a 3D tensor representation, to which different subsequent views are unprojected and integrated. Depth and FG masks are estimated directly from RGB input using U-nets, and the different 3D representations are aligned with the first viewpoint in the sequence using ground truth odometry (using groundtruth ego-motion is standard in the community when working with simulated environments). From the 3D representation, which is updated using a recurrent layer, different output layers estimate different desired quantities: reconstruction map (voxel occupancy), segmentation map, etc. A policy output estimates the next view from a discrete action space.