SuperPrimitive: Scene Reconstruction at a Primitive Level
Authors: Kirill Mazur, Gwangbin Bae, Andrew J. Davison

Joint camera pose and dense geometry estimation from a set of images or a monocular video remains a challenging problem due to its computational complexity and inherent visual ambiguities. Most dense incremental reconstruction systems operate directly on image pixels and solve for their 3D positions using multi-view geometry cues. Such pixel-level approaches suffer from ambiguities or violations of multi-view consistency (e.g. caused by textureless or specular surfaces). We address this issue with a new image representation which we call a SuperPrimitive. SuperPrimitives are obtained by splitting images into semantically correlated local regions and enhancing them with estimated surface normal directions both of which are predicted by state-of-the-art single image neural networks. This provides a local geometry estimate per SuperPrimitive while their relative positions are adjusted based on multi-view observations. We demonstrate the versatility of our new representation by addressing three 3D reconstruction tasks: depth completion few-view structure from motion and monocular dense visual odometry. Project page: https://makezur.github.io/SuperPrimitive/