Do you need computer vision to read construction drawings?
floorplan-parser pulls line geometry out of a drawing PDF two ways: it reads the vector paths the PDF already stores, or it renders the page to pixels and finds the lines with classic computer vision (threshold and Hough lines, no neural network). Both are scored against the drawing's own geometry. This recovers lines, not meaning: it does not know a wall from a door.
uv run python -m floorplan_parser --input plan.pdf --method vector --output out/plan
Code (MIT): github.com/dzakybd/floorplan-parser. Write-up: dzaky.ai.id. Results were computed ahead of time; this page runs no model.
Synthetic drawing
Score
Precision and recall are measured by length: how much of the extracted linework lies on the true lines (within 2 pt and 5°), and how much of the true linework was found. Time is the extraction call on an Apple M3 Pro, median of 3 runs.
Held-out FloorPlanCAD drawings (numbers only)
Ten real CAD drawings from the FloorPlanCAD test set: the original three examples plus seven selected within file-size strata using seed 20261019. The raster settings were tuned on the synthetic drawings only, then frozen and evaluated on these. F1 by length, with the number of extracted pieces in brackets.