I need to use this map (PNG file) in which each color is a population density:
I've already located it using Georeferencing. Now I need to convert it to shapefile with polygons, and narrow down its colormap to 5, using ArcMap 10.3.
How can I convert it to polygon, with the right tolerance (because conversion from raster tool just made too may polygons), and how to introduce line as boundaries, not another polygon. And after that, how to classify about 200 colors in the image into 5, and add value to them?