I am completing an analysis project for my ArcGIS class. I am analyzing the correlation between indigenous populations and food security in Guatemala. Since there is not a lot of information out there on this topic, I had to georeference .jpg maps I found online. I now have two RGB raster datasets: one shows the distribution of indigenous populations, and the other shows regional percentages of food scarcity. I would like to display the indigenous population raster layer as Quantities laid over the regional areas of food scarcity, therefore I have to convert it to vector data. I am having trouble finding a tool that can do this.
Best Answer
You have the municipality boundaries as a shapefile, and your jpeg has "homogeneous" values inside each municipality. Therefore, the best method to get your values is tansfer the values of eac band. It is easy if you have spatial analyst licence:
1) feature to point with the "inside" option to build the centroid (or add XY fields and make XY event layer if you don't have the licence)
2) extract multiple value to point
3) join the points' table to the polygons' table and you have the RGB attributes for each boundary.
Now it depends how your map was coded: either each banb has a meaningfull value and you are done, or this was a colormap and you need to find the relationship between the RGB values and the actual values (need to have information such as the legend to infer this)