Raster Scribe
Interactively trace lines in RGB raster maps with live previews, color sampling, and snapping.
Trace contours, roads, and other lines with live previews, color sampling, snapping, and configurable shortcuts.
Create a temporary line layer, or use an editable MultiLineString or MultiCurve layer.
Requires a GDAL-readable north-up raster with RGB values in bands 1-3. Single-band grayscale
or black-and-white and indexed/palette rasters need conversion to RGB. Rotated, skewed,
and flipped mappings are unsupported. Ordinary LineString layers are unsupported.
Optional Enhanced tracing (slower) uses a bundled Python HFM solver to follow interrupted contours.
Uses the Python libraries supplied with QGIS; no extra dependencies or compiled solver need installing.
Raster Scribe is an independently maintained fork of Raster Tracer by Mikhail Kondratyev.
License: GNU GPL version 3 or later; original component notices are preserved in NOTICE.txt.
https://github.com/IongIer/raster_scribe/blob/master/LICENSE
Original project: https://github.com/mkondratyev85/raster_tracer