Brent Perteet 2719ec244d Add PNG to SVG color separation tool for multi-color 3D printing ...

Created split_png_by_brightness.py to split rasterized logos into separate
SVG files by color for Underground Magnetics logo conversion.

Key features:
- OpenCV contour hierarchy detection for proper hole handling
- Letters with enclosed shapes (d, o, g, etc.) now render correctly
- Tight brightness thresholds to avoid antialiasing artifacts
- Automatic bounding box cropping for optimal file sizes
- Black text: brightness < 40 (236k pixels, 21 shape groups)
- Grey icon: brightness 108-118 (119k pixels, 2 shape groups)

Results:
- um_black.svg: 6.1KB, 3070x233px (was 139KB, 3613x391px)
- um_grey.svg: 728B, 413x390px (was 253KB, 3613x391px)

Files:
- split_png_by_brightness.py: Main color separation tool
- IMPROVEMENTS.md: Detailed changelog and comparison
- README_underground_magnetics.md: Usage documentation
- underground-magnetics.eps: Source logo file
- um_black.svg: Separated black text (cropped)
- um_grey.svg: Separated grey icon (cropped)
- requirements.txt: Added opencv-python dependency

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

2026-05-31 09:51:24 -05:00

8.4 KiB

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