autocad-image-redraw

name

autocad-image-redraw

description

Convert raster drawing references—including screenshots, scans, photos, sketches, exported PNG/JPG files, and photographed plans—into structured, editable AutoCAD DWG/DXF drawings with explicit evidence tracking, input preflight, specification validation, output inspection, and visual comparison. Use for dimension-driven redraws, hybrid reconstruction, visual tracing, or geometry-only redraws when the source is an image rather than a trustworthy source DWG.

AutoCAD Image Redraw

Reconstruct an image as an auditable CAD drawing. Treat the image as evidence, not as ground truth. If a trustworthy source DWG exists, use autocad-dwg-redraw instead.

Non-Negotiable Rules

1. Never claim physical accuracy from pixel similarity alone.
2. Resolve geometry in this order: explicit user requirements, readable dimensions, derived constraints, calibrated image measurements, then clearly labeled visual estimates.
3. Track every important value as known, scaled, inferred, or unreadable.
4. Calibrate each view or region independently when perspective or differing view scales are present.
5. Do not silently choose between conflicting dimensions. Record the conflict and return needs_review or blocked.
6. Preserve the original image, specs, reports, previews, and hashes so the result can be reproduced.

Choose a Profile

• strict-dimensioned: engineering deliverable; requires readable units and enough known or calibrated anchors to constrain the geometry.
• general: balanced default for plans, sketches, screenshots, and mixed-quality references.
• hybrid: use dimensions where available and calibrated proportions elsewhere; label inferred geometry.
• visual-trace: reproduce visible linework without asserting real-world scale.
• geometry-only: retain object geometry and useful construction layers; omit dimensions, leaders, notes, and table text.

If the source lacks a unit or scale anchor, choose visual-trace or use unitless. Do not default to millimeters merely because the drawing looks technical.

Runtime Requirements

Use Windows with AutoCAD and pywin32 for DWG generation/inspection. Preflight and comparison require Pillow, NumPy, and OpenCV; DXF preview requires ezdxf and PyMuPDF:

python -m pip install pywin32 pillow numpy opencv-python ezdxf pymupdf

End-to-End Workflow

1. Preserve and preflight the source

Copy the source into the project, compute a hash, and inspect readability before interpreting it:

python scripts\preflight_image_redraw.py --image input.jpg --mode general --output reports\input-preflight.json

Review rotation, crop, resolution, contrast, blur, perspective, occlusion, visible units, and available scale anchors. A quality warning is not automatically a blocker; it becomes a blocker when the selected profile requires evidence the image cannot provide.

2. Build a semantic redraw spec

Use references/image-redraw-spec.md. Create stable entity IDs, identify each view, record calibration anchors and evidence, and encode constraints rather than relying on raw pixel coordinates.

Keep source and CAD coordinate systems separate:

• source coordinates: image pixels, origin at top-left;
• CAD coordinates: drawing units, origin chosen for auditability;
• calibration: a view-specific affine, homography, or dimension-based relationship between them.

3. Validate the spec before drawing

python scripts\validate_image_redraw_spec.py --spec redraw-spec.json --profile general --report reports\spec-validation.json

Resolve errors, impossible geometry, duplicate IDs, missing required fields, invalid units, and constraint failures. In strict-dimensioned, missing units or calibration evidence must block drawing.

4. Draw in AutoCAD

python scripts\draw_image_spec.py --spec redraw-spec.json --output outputs\redraw.dwg

For Chinese text:

python scripts\draw_image_spec.py --spec redraw-spec.json --output outputs\redraw.dwg --text-style CN_TEXT --text-font "C:\Windows\Fonts\simhei.ttf"

For geometry-only output:

python scripts\draw_image_spec.py --spec redraw-spec.json --output outputs\redraw-geometry.dwg --geometry-only

When multiple AutoCAD instances or the Start page confuse COM, use --attach-document with a readable DWG. Use --dry-run before connecting to AutoCAD.

For rough, open-source visual tracing without AutoCAD, use image_to_dxf_open_source.py. For vector PDFs, use pdf_vector_to_dxf.py before raster tracing. Neither path converts uncertain pixels into authoritative dimensions.

5. Inspect the CAD output

python scripts\inspect_dwg_output.py --dwg outputs\redraw.dwg --report reports\dwg-inspection.json

Verify the file opens, ModelSpace is nonempty, units match the spec, expected layers and entity classes exist, and forbidden annotation classes are absent in geometry-only mode. Export an auditable DXF from AutoCAD, then audit and render it:

python scripts\render_dxf_preview.py --dxf outputs\redraw.dxf --png reports\cad-preview.png --pdf reports\cad-preview.pdf

6. Compare against the source

Create an anchors JSON containing corresponding source-image and CAD-preview points, then run:

python scripts\compare_redraw.py --source input.jpg --cad-preview reports\cad-preview.png --anchors anchors.json --output-dir reports\comparison

Inspect the side-by-side image, registered overlay, difference view, edge coverage, and edge-distance statistics. Use the comparison to find omitted walls, shifted holes, incorrect arcs, text collisions, and view-layout errors. Do not use it to validate physical dimensions.

7. Iterate and issue a disposition

Fix the highest-impact failure, regenerate, and rerun validation. Finish with one status:

• pass: selected profile and all required checks passed;
• pass_with_warnings: deliverable is usable with documented noncritical uncertainty;
• needs_review: a human decision is required, usually due to conflicting or inferred evidence;
• blocked: required source evidence is missing;
• fail: output is corrupt or violates a mandatory check.

Delivery Contract

Deliver as applicable:

• editable DWG and audit DXF;
• redraw spec JSON and calibration/anchor JSON;
• input preflight, spec validation, and DWG inspection reports;
• fixed-page PNG/PDF preview;
• side-by-side, overlay, difference image, and metrics JSON;
• manifest containing source/output hashes, selected profile, units, assumptions, warnings, and final status.

References and Scripts

• references/image-redraw-spec.md: generalized spec, evidence, views, calibration, constraints, and entities.
• references/image-redraw-validation.md: acceptance policies, checks, metrics, statuses, and report contract.
• scripts/preflight_image_redraw.py: source-image quality and evidence gate.
• scripts/validate_image_redraw_spec.py: semantic and constraint validation.
• scripts/draw_image_spec.py: JSON-to-DWG AutoCAD renderer.
• scripts/inspect_dwg_output.py: read-only DWG structure inspection through AutoCAD COM.
• scripts/render_dxf_preview.py: DXF audit and deterministic fixed-page preview.
• scripts/compare_redraw.py: registered visual comparison and edge metrics.
• scripts/image_to_dxf_open_source.py: rough raster-to-DXF baseline.
• scripts/pdf_vector_to_dxf.py: vector-PDF extraction path.