Title
Acorn: adaptive coordinate networks for neural scene representation
Abstract
AbstractNeural representations have emerged as a new paradigm for applications in rendering, imaging, geometric modeling, and simulation. Compared to traditional representations such as meshes, point clouds, or volumes they can be flexibly incorporated into differentiable learning-based pipelines. While recent improvements to neural representations now make it possible to represent signals with fine details at moderate resolutions (e.g., for images and 3D shapes), adequately representing large-scale or complex scenes has proven a challenge. Current neural representations fail to accurately represent images at resolutions greater than a megapixel or 3D scenes with more than a few hundred thousand polygons. Here, we introduce a new hybrid implicit-explicit network architecture and training strategy that adaptively allocates resources during training and inference based on the local complexity of a signal of interest. Our approach uses a multiscale block-coordinate decomposition, similar to a quadtree or octree, that is optimized during training. The network architecture operates in two stages: using the bulk of the network parameters, a coordinate encoder generates a feature grid in a single forward pass. Then, hundreds or thousands of samples within each block can be efficiently evaluated using a lightweight feature decoder. With this hybrid implicit-explicit network architecture, we demonstrate the first experiments that fit gigapixel images to nearly 40 dB peak signal-to-noise ratio. Notably this represents an increase in scale of over 1000X compared to the resolution of previously demonstrated image-fitting experiments. Moreover, our approach is able to represent 3D shapes significantly faster and better than previous techniques; it reduces training times from days to hours or minutes and memory requirements by over an order of magnitude.
Year
DOI
Venue
2021
10.1145/3450626.3459785
ACM Transactions on Graphics
Keywords
DocType
Volume
Neural Signal Representation
Conference
40
Issue
ISSN
Citations 
4
0730-0301
1
PageRank 
References 
Authors
0.38
0
6
Name
Order
Citations
PageRank
Julien N P Martel1287.46
David B. Lindell2467.19
Connor Z. Lin310.72
Eric R. Chan411.06
Marco Monteiro510.72
Gordon Wetzstein694572.47