imandel/boards-in-the-wild

Boards in the Wild

Boards in the Wild relates electronic CAD (ECAD) designs of printed circuit boards to photographs of the fabricated, populated boards built from them. Each accepted mapping links one side of one normalized board design to one photograph region showing that populated board, with a registration (homography) between the design and the photograph. It accompanies the paper Boards in the Wild (SCF '26, DOI 10.1145/3828611.3845653).

Code (schemas, loader, rehydration, overlay and projection examples, paper figures): https://github.com/imandel/boards-in-the-wild.

What is hosted and what is linked. This repository hosts metadata, mappings, labels, evaluation data and the openly licensed CAD files (raw and normalized). It hosts no photographs and no CAD bytes whose recorded terms do not permit redistribution: for those it records the source URL/page, SHA-256, byte size and a retrieval recipe, and the code repository downloads and verifies them.

Counts (release 1.0.0, accepted set paper-accepted-mappings/v3-safe)

unit	count
sources	25
release-scoped source records	14,897 (14,895 CAD-scope records plus 2 referenced only as photo sources)
CAD board-file candidates	22,774
mirrored (openly licensed) / reference-only	5,901 / 16,873
normalized board objects	14,024
mirrored / reference-only	5,149 / 8,875
candidate photographs, links only: distinct images (photo locations)	53,526 (76,247)
accepted mappings	9,449
normalized objects / distinct images (photo locations) in accepted mappings	3,998 / 9,239 (9,398)
mappings with mirrored / reference-only CAD	5,005 / 4,444
mirrored raw file locations / unique contents / bytes	34,928 / 25,474 / 10.60 GB
leakage families (train / validation / test)	3,618 (2,832 / 388 / 398)
mappings per split (train / validation / test)	7,086 / 1,112 / 1,251

Reference-only candidates: no accepted redistribution evidence 12,457; noncommercial license evidence 57; ti restricted noncommercial terms 4,359.

Files

path	rows	contents
data/board_candidates.parquet	22,774	22,774 CAD board-file candidates with license class, mirror flag and retrieval recipe.
data/cad_files.parquet	144,247	144,247 release-scoped raw CAD/project file locations: hash, size, license class, mirror path (mirrored) or retrieval recipe (reference-only).
data/evaluation/landmark_annotations.parquet	457	Blinded landmark correspondences (render pixels <-> photo pixels) and per-landmark errors of the accepted homography for 76 usable mappings.
data/evaluation/landmark_format_side_metrics.parquet	8	Landmark error by source format and side.
data/evaluation/landmark_primary_relation_metrics.parquet	76	Per-mapping landmark error summaries (76 usable).
data/evaluation/landmark_primary_unusable_subjects.parquet	4	Landmark subjects judged unusable (4) with reasons.
data/evaluation/landmark_repeat_corner_transform_errors.parquet	64	Repeat vs primary fitted-transform corner errors.
data/evaluation/landmark_repeat_cross_annotation_errors.parquet	192	Repeat vs primary annotation discrepancies.
data/evaluation/landmark_repeat_relation_metrics.parquet	16	Repeat-annotation per-mapping metrics (16 repeats).
data/evaluation/multiboard_review.parquet	410	Direct review outcomes for the 410 multi-board candidates (378 accepted).
data/evaluation/precision_final_labels.parquet	600	v2 precision evaluation: final adjudicated labels of the 600-mapping sample (anonymous rater slots); mapping_id is the v2 relation id.
data/evaluation/precision_sampling_frame.parquet	3,937	v2 precision evaluation: eligible v2 mappings with strata (format x side) and inclusion probabilities; mapping_id is the v2 relation id, in_this_release flags membership here.
data/evaluation/v3/precision_final_labels.parquet	600	Final adjudicated labels of the 600-mapping v3 precision sample (anonymous rater slots), with the v3-safe subset flag.
data/evaluation/v3/precision_sampling_frame.parquet	4,901	v3 precision evaluation frame after exclusion of previously labelled/near-duplicate subjects: strata (format x side), inclusion probabilities, selected, in_v3_safe.
data/evaluation/v3/precision_summary.json		summary
data/labels/cad_components.parquet	465,121	CAD components (board-mm placement, refdes, category, DNP) of accepted objects; value/footprint for mirrored only
data/labels/coco/public_component_labels.json		COCO (public export stage8-public-component-labels/v1): link-only images, component annotations, board/render/photo matrices
data/labels/coco/public_component_labels.development_test.json		COCO (public export stage8-public-component-labels/v1): link-only images, component annotations, board/render/photo matrices
data/labels/coco/public_component_labels.development_train.json		COCO (public export stage8-public-component-labels/v1): link-only images, component annotations, board/render/photo matrices
data/labels/coco/public_component_labels.development_validation.json		COCO (public export stage8-public-component-labels/v1): link-only images, component annotations, board/render/photo matrices
data/labels/component_geometries.parquet	4,072,027	fab/courtyard/silk/pad polygons in board mm, mirrored designs only (source license)
data/labels/components.parquet	534,708	one row per public COCO annotation (component region in photo px; refdes, category, DNP)
data/labels/open_cad_pads.parquet	721,356	pads of mirrored-CAD mappings in board mm and photo px, with source license
data/labels/pad_attributes.parquet	327,662	pad type/shape/copper layers/drill, mirrored designs only (source license)
data/license_observations.parquet	5,404	Recorded license/terms evidence per project group (one row per group, evidence reason, expression) behind the frozen submission rights decisions.
data/mappings.parquet	9,449	Accepted photo<->CAD mappings: normalized object, side, photo, render->photo homography, board polygon, board-mm->photo transform where validated, QA fields, split.
data/mirror_files.parquet	30,623	Every hosted file under mirror/: SHA-256, size, license expression(s), attribution, retrieval date (earliest catalog file time).
data/normalized_objects.parquet	14,024	14,024 normalized KiCad board objects with provenance links, design metrics and distribution class (mirrored if any alias board candidate is mirrored).
data/photos.parquet	76,247	76,247 candidate photographs (links only; no photo bytes hosted): SHA-256, size, display-frame width/height, EXIF orientation, source URL/page, verification.
data/project_groups.parquet	11,098	11,098 project groups (source-record closures).
data/source_records.parquet	14,897	Release-scoped source records (CAD scope, photo claims, mapping provenance) with page URLs, record-level license observations and the source-native payload.
data/sources.parquet	25	The 25 acquisition sources with their recorded site terms.
data/splits.parquet	3,618	Family-disjoint train/validation/test split over transitive leakage families (stage8 split table; rule and merge case per family).
mirror/raw/<sha[:2]>/<sha256>	25,474	openly licensed raw CAD/project files, byte-identical to the source, named by SHA-256
mirror/normalized/<sha[:2]>/<sha256>.kicad_pcb	5,149	normalized KiCad boards of mirrored designs
manifest.json		tables, row counts, schema versions, input receipts and counts
checksums.sha256		SHA-256 of every file in this revision

Every Parquet file carries boards_in_the_wild.schema_version in its file metadata. Key joins: mappings.normalized_object_id → normalized_objects, mappings.photo_id → photos, mappings.cad_candidate_ids → board_candidates.candidate_id = cad_files.file_id, mappings.leakage_family_id → splits, cad_files.mirror_path → mirror_files.

Mappings carry: normalized object, side, photo; the render→photo homography (render_to_photo_homography, registration-render pixels → photo pixels, with the render recipe in render_meta_json); the board-mm→photo transform (board_to_photo_matrix, KiCad SVG board frame in millimetres → photo pixels) where a validated board transform exists (board_transform_status; otherwise only the render→photo homography is published and the row is flagged); the board polygon in photo pixels; the photo coordinate frame, size and EXIF orientation; the acceptance cohort, consensus corner delta and QA fields; the leakage family and split.

Licensing (mixed)

• Our metadata, annotations, labels, mappings and code-generated tables: CC BY 4.0.
• Mirrored CAD files keep their own licenses, listed per file in data/mirror_files.parquet (license_expressions, attribution, retrieved_at_earliest) and per location in data/cad_files.parquet. They include permissive and copyleft open-hardware licenses (e.g. MIT, Apache-2.0, CERN-OHL-P/W/S, TAPR-OHL, CC BY, CC BY-SA, GPL) and source-specific grants (Arduino CC BY-SA 4.0, Espressif Apache-2.0, Bus Pirate CC0-1.0, Pixhawk CC BY-SA 3.0, u-blox deliverable terms), with the exact recorded terms per file.
• Normalized KiCad files and full pad/net/copper geometry derived from a mirrored design follow that design's license, including share-alike terms (CC BY-SA, GPL, CERN-OHL-S); CC BY 4.0 covers only our metadata, mappings and component-level labels.
• Reference-only CAD (everything else, including TI designs under noncommercial terms and every design with noncommercial license evidence): no CAD bytes, normalized files, renders or full geometry are hosted — only URL, SHA-256, size, retrieval recipe, our homographies and component-level labels.
• Photographs are not hosted. They remain the property of their publishers.

Mirror eligibility follows a frozen submission-time policy (decision snapshot rights_submission_v2_87cb7310c35234373667c0f10ec420fe); it is a release-policy classification, not legal advice or a guarantee that a file is free of other rights.

Photo coordinate convention

All photo coordinates are in the EXIF-oriented display frame: OpenCV cv2.imread with IMREAD_COLOR, EXIF orientation applied (matcher_cv2_imread_color_exif_applied/v1). Each photo records its original EXIF orientation. 244 of the 76,247 candidate photos, and 27 of the 9,398 accepted-mapping photos, have a rotation tag (receipt: EXIF census match-expand-v3-exif-census-v1).

Photographs: links only

Per photo: direct_url (download URL recorded at acquisition, a GitHub raw path on the recorded default branch, or a vendor CDN URL reconstructed from the recorded file name — the latter published only when the served bytes matched our SHA-256), page_url (product/project/repository page), SHA-256, byte size, display-frame width and height, EXIF orientation, source record and url_check (sha256_match, sha256_mismatch, unreachable:…, not_checked, or derived_from_document for images extracted from a vendor PDF, with derived_from_url and derived_from_page) with url_checked_at and url_recovery_method. Unverified URLs are kept as recorded; a mismatch usually means the host now serves a re-encoded rendition, so verify before use. Some CDNs serve different encodings from different edge servers, so even a verified URL can occasionally return other bytes; the rehydration tool reports this as hash_mismatch and a retry later may succeed. URL coverage for accepted-mapping photos: 7,269 of 9,239 distinct images have at least one photo location with a verified direct URL; by photo location: derived from document 153/9398, direct url unverified 678/9398, page or repo url only 1158/9398, verified direct url 7409/9398.

Labels

Component labels are nominal design intent projected from the CAD: amodal (occluded parts are included), DNP/DNI footprints flagged rather than removed, and not visibility-verified — they do not establish that a part is present, visible, populated or assembled as designed. Labels are in data/labels/: the public COCO export (coco/public_component_labels*.json, stage8-public-component-labels/v1; 9,393 mappings with a validated board transform, 534,708 component annotations, link-only images) and Parquet views of it (components.parquet), CAD component placement for every accepted object (cad_components.parquet), and — for mirrored designs only, under the source license — pad polygons (open_cad_pads.parquet), full fab/courtyard/silk/pad geometry (component_geometries.parquet) and pad attributes (pad_attributes.parquet). The 56 mappings without a validated board transform carry the render→photo homography only and no labels.

Splits

Family-disjoint train / validation / test over transitive leakage families: two mappings share a family when they share a project group, source record, photo file location, photo bytes (SHA-256), normalized CAD bytes or raw CAD bytes, or, where the seed plan recorded one, the same 768-px visual content hash (re-encoded near-duplicate photos are otherwise not merged). Each family is assigned by rule stage8-development-split/v1.1-byte-closure (SHA-256 of the family id, 80/10/10); merged families keep a shared split or take the most protective one (test > validation > train). The same split table labels the COCO export.

Evaluation data

v3 — this release's accepted set (data/evaluation/v3/): precision_sampling_frame.parquet (the 4,901 v3 mappings not previously labelled, with format×side strata, inclusion probabilities, selected and in_v3_safe), precision_final_labels.parquet (600 final adjudicated labels, three anonymous rater slots, in_v3_safe) and precision_summary.json. Strict endpoint (correct board and revision, correct side, populated physical board instance, usable registration, no unresolved competing mapping; unclear counts as failure): v3-safe 571/581 = 98.3% valid (Wilson 95% 96.9–99.1%); all 600 sampled v3 mappings 590/600 = 98.3% (97.0–99.1%). Before adjudication 580/600 labels were unanimous (Gwet AC1, binary, 0.977); the 20 disagreements were adjudicated blind. The sample is proportional over format×side, so its v3-safe members are a self-weighting random sample of v3-safe.

v2 — the previous accepted set, kept for reference (files directly under data/evaluation/):

• data/evaluation/precision_sampling_frame.parquet — the 3,937 eligible mappings with format×side strata and inclusion probabilities; precision_final_labels.parquet — final adjudicated labels of the 600-mapping sample (three anonymous rater slots).
• data/evaluation/landmark_*.parquet — blinded landmark correspondences (render pixels ↔ photo pixels) and error summaries for 80 mappings (76 usable) and 16 repeats.
• data/evaluation/multiboard_review.parquet — direct-review outcomes for the 410 multi-board candidates (378 accepted).

No reviewer identities are included. mappings.in_precision_sample_600 and in_landmark_sample_80 refer to these v2 samples; in the v2 evaluation files mapping_id is the v2 relation id and in_this_release flags whether that mapping is also in this release.

Known limitations

• Coverage reflects sources with attributable public documentation, downloadable ECAD and usable photographs; it does not represent all manufactured PCBs or format market share.
• Candidate recall is bounded by provenance links and an early-exit matching schedule; precision was evaluated (v3-safe 571/581 strictly valid; v2 set 587/600) but end-to-end recall was not.
• Normalization verifies a nonempty board, not that every design detail survived import. SHA-256 identifies bytes, not semantic design or revision identity.
• Projected labels transfer nominal design intent (see Labels); photographs show only the outer layers.
• Not every CAD footprint is a component. The board_hardware class includes single-copper-pad footprints such as stitching vias that designers place as footprints, so a few boards contribute thousands of board_hardware regions (e.g. the LimeRFE 8001P has 4,741 board_hardware of its 5,716 annotations); footprints that could not be classified (unresolved_component) can include large non-component regions such as outline or artwork footprints. Filter by category and area as your task requires.
• Unhosted photographs and files remain subject to upstream deletion, URL changes and license revisions; hashes, dates and recipes improve reproducibility but cannot guarantee access.

Citation

@inproceedings{mandel2026boards,
  title     = {Boards in the Wild},
  author    = {Mandel, Ilan and Castillo, Joey and Ju, Wendy and Roumen, Thijs},
  booktitle = {Proceedings of the 11th ACM Symposium on Computational Fabrication (SCF '26)},
  year      = {2026},
  publisher = {ACM},
  doi       = {10.1145/3828611.3845653}
}

Takedown and contact

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