3D Object Recognition By Corresponding and Quantizing Neural 3D Scene Representations

TL;DR

This paper introduces a self-supervised 3D object recognition system that learns view-invariant 3D features from RGB-D images, enabling accurate object detection and pose estimation without relying on labeled 3D data.

Contribution

The proposed model maps RGB-D images to 3D feature maps and clusters them into prototypes, allowing pose and scale estimation without strong supervision.

Findings

Outperforms baselines in object retrieval and pose estimation

Features are invariant to viewpoint and scale changes

Enables unsupervised learning of 3D object representations

Abstract

We propose a system that learns to detect objects and infer their 3D poses in RGB-D images. Many existing systems can identify objects and infer 3D poses, but they heavily rely on human labels and 3D annotations. The challenge here is to achieve this without relying on strong supervision signals. To address this challenge, we propose a model that maps RGB-D images to a set of 3D visual feature maps in a differentiable fully-convolutional manner, supervised by predicting views. The 3D feature maps correspond to a featurization of the 3D world scene depicted in the images. The object 3D feature representations are invariant to camera viewpoint changes or zooms, which means feature matching can identify similar objects under different camera viewpoints. We can compare the 3D feature maps of two objects by searching alignment across scales and 3D rotations, and, as a result of the operation, we can estimate pose and scale changes without the need for 3D pose annotations. We cluster object feature maps into a set of 3D prototypes that represent familiar objects in canonical scales and orientations. We then parse images by inferring the prototype identity and 3D pose for each detected object. We compare our method to numerous baselines that do not learn 3D feature visual representations or do not attempt to correspond features across scenes, and outperform them by a large margin in the tasks of object retrieval and object pose estimation. Thanks to the 3D nature of the object-centric feature maps, the visual similarity cues are invariant to 3D pose changes or small scale changes, which gives our method an advantage over 2D and 1D methods.