I used QGIS to georeference a raster file of a custom US map. The map has features which are not strictly defined by state borders. I would like to digitize the map by creating contiguous borders for each feature. I tried that a few different way, but none of them really worked:
- traced the borders with polylines, and digitizing with the Polygonizer plugin. The plugin kept crashing.
- used Conversion > Raster > Vectorize (Raster to Vector). That one worked, but the result was many overlapping polygons for each feature, each with slightly different borders.
I have somewhere between 50-100 different raster images to process, which is why any automated solution is highly preferred. I'm new to GIS software, but could easily pre-process the images if needed, either manually or with a custom script (using Python/PIL, ImageMagick, Photoshop batch processing or similar tools).
Thanks for any pointers!