I'm trying to turn a PNG that looks like this to a shapefile with polygons that keep the categories marked by the colors on the map.

I have several maps to process, so manually tracing the polygons is not a valid option.

I tried already with this Python function, but I get the following error:

Runtime error  Traceback (most recent call last):   File "<string>", line 5, in <module>   File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\conversion.py", line 337, in RasterToPolygon     raise e ExecuteError: ERROR 010151: No features found in c:\gis\output\control_test.shp. Possible empty feature class. Failed to execute (RasterToPolygon).

Is it possible to fix this error or to use another function to get to my goal?

I have the original PNG as an SVG with vector drawn polygons if that helps.

Thanks!