Check Seed Lines — Algorithm Notes
Related user page: Check Seed Lines
Purpose
Prepare and normalize input seed lines so downstream centerline/corridor tools receive clean, consistent geometry.
Inputs and outputs
- Inputs: seed line vector, optional CHM raster
- Output: cleaned seed line vector
Main processing stages
- Normalize line geometries (multipart handling)
- Remove invalid/empty/degenerate features
- Optional short-line filtering
- Optional CHM footprint clipping (with inward shrink)
- Optional endpoint-only snapping
- Split at intersections
- Optional grouping and merge
- Optional densification of long segments
Assumptions
- Input is line geometry.
- Distance thresholds are interpreted in meter-like projected units.
- Raster footprint approximates valid-data extent.
Edge cases
- Excessive shrink distance can remove all line coverage.
- Aggressive minimum length can over-prune short valid segments.
- Snapping tolerance larger than intended can over-connect nearby lines.
Notes for maintainers
- Keep QC stages deterministic and independent where possible.
- Preserve clear logs for each pruning/cleanup stage.