Papers › SNAP: Self-Supervised Neural Maps for Visual Positioning and Semantic Understanding

SNAP: Self-Supervised Neural Maps for Visual Positioning and Semantic Understanding

8 Jun 2023NeurIPS 2023 11arXiv:2306.05407archive 2025-07-28

Paul-Edouard Sarlin, Eduard Trulls, Marc Pollefeys, Jan Hosang, Simon Lynen

Semantic 2D maps are commonly used by humans and machines for navigation purposes, whether it's walking or driving. However, these maps have limitations: they lack detail, often contain inaccuracies, and are difficult to create and maintain, especially in an automated fashion. Can we use raw imagery to automatically create better maps that can be easily interpreted by both humans and machines? We introduce SNAP, a deep network that learns rich neural 2D maps from ground-level and overhead images. We train our model to align neural maps estimated from different inputs, supervised only with camera poses over tens of millions of StreetView images. SNAP can resolve the location of challenging image queries beyond the reach of traditional methods, outperforming the state of the art in localization by a large margin. Moreover, our neural maps encode not only geometry and appearance but also high-level semantics, discovered without explicit supervision. This enables effective pre-training for data-efficient semantic scene understanding, with the potential to unlock cost-efficient creation of more detailed maps.

PaperPDFConference PDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="2306.05407")

Code

Syntology Ran 1 of 8 code samples harvested from 1 repository linked to this paper; 7 have no recorded run. Of those that ran: 1 ran · honoured contract.

By repository: official repository: 8 samples from 1 repository, 1 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

google-research/snap officialmentioned in papermentioned on GitHubjaxApache-2.0 report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

8 samples harvested; 1 ran; 1 honoured the contract we drafted; 7 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · honoured contract
7unverified

Licence: 7 of the 8 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from google-research/snap. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

get_block_desc google-research/snap/snap/models/resnet.py official repository ran · honoured contract fingerprinted Apache-2.0 (permissive) · 4f697aeaa3747cc2 · report
balancing_weights google-research/snap/snap/models/semantic_net.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · 5a7176d92f373893 · report
masked_mean google-research/snap/snap/models/layers.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · c1386112ff3f93ea · report
masked_softmax google-research/snap/snap/models/layers.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · ee3edbe8686ce0eb · report
normalize google-research/snap/snap/models/layers.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · e4d204bc18f18435 · report
pad_to_multiple google-research/snap/snap/models/image_encoder.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · 3f53d845c39b8bf4 · report
standardize google-research/snap/snap/models/resnet.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · f0dbdc7813be0fcd · report
template_matching google-research/snap/snap/models/pose_exhaustive_voting.py official repository unverified Apache-2.0 recorded; this copy not marked cleared · pointer only · 703f7585dc88471c · report

Tasks

Scene Understanding

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Methods

ALIGN

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections