For a task I have several maps created with GIS that look like the following:
I am mainly interested in the colored zones that aren't roads (red) or rivers (blue) and would like to turn these into vectors for further spatial analysis. The extraction of this by a simple Raster to Vectors gives me incomplete lines/polygons because the edges of these zones aren't sufficiently sharp.
I have tried some approaches using reclassify values (with SAGA) to clean up the edges somewhat, edge detection using the Orfeo Toolbox, and raster calculator to make the non-white values stronger, but this doesn't seem to lead to sharper edges. Because these zones have a lot of edges, manual digitizing of the edges would be too time-consuming.
Are there any ways to automatize this process?