OCR for construction documents does not work, we fixed it

Posted by wcisco17 3 hours ago

OCR for construction documents does not work, we fixed it(www.getanchorgrid.com)

So we've built an API and trained models that detects fixtures, extracts schedules, and analyzes construction documents. Check us out!

More examples: - https://www.getanchorgrid.com/developer/docs/endpoints/drawi...

Main website: - https://www.getanchorgrid.com/developer

Why we did it: https://www.getanchorgrid.com/developer/docs/changelog/const...

61 points | 42 comments

Terr_ 1 hour ago|

> OCR for construction documents does not work

I'm reminded of the Xerox JBIG2 bug back in ~2013, where certain scan settings could silently replace numbers inside documents, and bad construction-plans were one of the cases that led to it being discovered. [0]

It wasn't overt OCR per se, end-user users weren't intending to convert pixels to characters or vice-versa.

[0] https://www.youtube.com/watch?v=c0O6UXrOZJo&t=6m03s

TehCorwiz 1 hour ago|

If I recall it was an artifact of the compression algo.

Full context and details: https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres...

sreekanth850 34 minutes ago||

We’re taking a different path, building a parsing engine that converts CAD (DWG/DXF) into fully structured JSON with preserved semantics (no ML in the critical path).We also have a separate GIS parser that extracts vector data (features, layers, geometries) independently, Like to know how you handle consistency and reproducibility across runs using models and how you make it affordable, especially at scale. because as far as i know CAD and GIS need precision and accuracy.

i18nagentai 21 minutes ago||

OCR accuracy on technical documents is one of those problems that looks 95% solved until you hit the edge cases. Construction docs are especially tricky because of mixed handwriting, stamps, revision clouds, and poor scan quality. Curious how you handle multi-language documents — a lot of international construction projects have specs in two or three languages on the same page.

frogguy 1 hour ago||

Looks cool! Where are you getting the data to finetune the cv models for element extraction? I'm worried there isn't a robust enough dataset to be able to build a detection model that will generalize to all of the slightly different standards each discipline (and each firm for that matter) use.

wcisco17 56 minutes ago|

good q — we don't train on customer drawings. Our detection models are trained on a curated dataset of architectural drawings we've sourced and labeled ourselves, focused on the most common fixture and element types across CSI divisions.

The generalization problem you're pointing at is real and it's the hardest part of this. Our approach is to keep the detection scope tight — rather than trying to generalize across every firm's conventions, we train on a small but high-quality set of fixtures and optimize for precision within that scope.

The result is high confidence outputs on the elements we support, rather than mediocre coverage across everything.

We're expanding the detection surface incrementally as we validate accuracy division by division!

dylan604 18 minutes ago||

How in the world is an answer to a question from the account posting TFA replying directly to said question getting killed?

testUser1228 1 hour ago||

What do you foresee being the end use case for this (or most valuable use case)?

wcisco17 1 hour ago|

Anyone building in or for construction tech — whether that's a startup building estimating or project management software, a construction company with an internal tech team solving this themselves, or a builder looking to automate their workflow. The common thread is drawings. Every one of those groups lives and dies by their ability to extract actionable data from a PDF that was never designed to be machine-readable. We're building the layer that makes that possible so they don't have to start from scratch.

wang_li 1 hour ago||

Why does the workflow lie at the level of a real or virtual piece of paper and not in the metadata from the applications used to create that piece of paper? Seems like a CAD tool would allow you to identify each element of the drawing, assigning metadata as required.

jsidney 1 hour ago|||

Only a small set of construction stakeholders participate in the CAD ecosystem (e.g., architects, large GCs) while a broader set of stakeholders (subcontractors, trades, smaller GCs/CMs) do not receive BIM files and work with PDFs. CAD/BIM is a wonderful aspiration but for many the reality is PDFs.

instig007 32 minutes ago||

Re. "CAD/BIM", technically speaking CAD doesn't imply BIM, and the industry's promotion of BIM is akin to AI promotion among software engineering teams - the benefits aren't clear upon detailed review of the advertised capabilities. The CAD part, on the other hand, is generally recognized as the essential tooling for the profession and I'm surprised to hear that it just is a "wonderful aspiration".

cyanydeez 1 hour ago|||

Oh you sweet summer child. These draws are anywhere from 0 to 120 years old and might just be something pulled out of a floppy disk from 1970 to scanned in coffee ridden pieces of paper sitting in a desk folded a hundred times.

The world in which metadata is a common thing attached to any file doesn't exist, and probably never will, no matter how much you try to improve CAD work flow.

Iulioh 2 hours ago||

When will this be available for 30000x8000px electrical diagrams?

I have to make a BOM and oh boy I hate my job

oritron 2 hours ago||

What software made the bitmap? Seems like a step earlier in the pipeline could help generate a BOM more easily.

Iulioh 1 hour ago||

I'm not really sure and I don't have access to it, I just recive flat PDFs or TIFFs

A lot of them are "archival" so I'm pretty OOL

dylan604 12 minutes ago||

You might even be SOL

It is telling that so many of the comments here assume the person with a thing that is not the most practical would be easily able to request thing in a different format. The assumption that the person with the inconvenient thing would never have thought to ask if more convenient thing was available and just willfully toiling with the inconvenient thing is kind of insulting.

alexeischiopu 1 hour ago|||

I’m building a similar platform, with electrical being furthest ahead - SLD, panels, lights, power, comms.

Also do doors, windows, and mechanical equipment.

dm, and I can include you in the next preview.

testUser1228 32 minutes ago|||

I'm not sure how to dm on here, but I'm very interested

Iulioh 1 hour ago|||

I work in the automotive field, I don't know if this complicates the things further but I appreciate any help!

jsidney 2 hours ago||

What do you hate the most?

stronglikedan 36 minutes ago||

silly questions

hspraggins77 1 hour ago||

Great points raised!

alexeischiopu 1 hour ago||

Good idea :)

wcisco17 1 hour ago|

Thanks!!

vessenes 1 hour ago||

cool. What's pricing like?

wcisco17 1 hour ago|

Thanks! https://www.getanchorgrid.com/developer/pricing

Let me know if you find it useful or have any questions, happy to help.

vessenes 1 hour ago||

Thanks -- btw the Pricing link on the site pulls up a form, not that page.

achillesheels 2 hours ago|

Love it! Starbucks Vente Machiato sip

Love to give it to an arc client, not sure who the right person to implement this would be? Hmm…

wcisco17 1 hour ago|

Hey OP here - Love to help if you're looking for a team to implement a solution.

https://cal.com/anchorgrid/anchorgrid-external-meeting?durat...

More comments...