Crane Hook Annotation

Detect and tightly annotate tower-crane hook outlines in similar construction-site monitoring images. Use when Codex needs to batch-process .png, .jpg, or .jpeg images from a stable camera view, locate the hook from bright metal pixels inside a known search region, export annotated copies, and produce reusable coordinates or polygon metadata for follow-up QA.

Use this skill when the user has many similar site-monitoring images and wants the crane hook outlined with a strict polygon rather than a loose box.

Workflow

1. Confirm the images are from a similar viewpoint.
2. Run annotate-crane-hooks.ps1 on one sample image first.
3. Inspect the annotated output and the manifest JSON.
4. If the hook is consistently shifted, edit default-monitoring-profile.json.
5. Re-run the same script on the full directory once the sample looks right.

Quick Start

Run a sample image:

powershell

powershell -ExecutionPolicy Bypass -File .\skills\crane-hook-annotation\scripts\annotate-crane-hooks.ps1 `
  -InputPath .\sample-image.jpg `
  -OutputDir .\hook-batch-output `
  -WriteDebugRoi

Run a directory:

powershell

powershell -ExecutionPolicy Bypass -File .\skills\crane-hook-annotation\scripts\annotate-crane-hooks.ps1 `
  -InputPath .\incoming-images `
  -OutputDir .\hook-batch-output `
  -Recurse

Outputs

• annotated/: annotated images with the strict hook polygon and label
• debug-roi/: optional ROI crops for inspection
• manifest.json: one record per image with component bbox, polygon points, and status

Tuning

Read profile-tuning.md when:

• the hook is detected but the outline is systematically shifted
• the hook search area is too narrow or too wide
• the user changes camera angle or image resolution
• a different site needs its own profile

Adjust these fields first:

• search_roi_norm
• bright_threshold
• filters
• reference_component_bbox_norm
• polygon_points_in_bbox_norm

Notes

• The current default profile is calibrated from the accepted hook outline in this workspace.
• The script assumes a bright metal hook against a darker construction background.
• Batch execution is safest when images come from the same or a very similar camera setup.