I have a very specific problem. I am trying to build an offline map on leaflet, rhomobile(based on ruby) and OSM data. The problem is that I am making now a offline layer images folder with the city data rendered and in average a big city is 200mb . In case that OSM data file is only 5mb .
What is the optimal way to do it less? Maybe geojson or something else?
I know for Tilemill you can export data to .mbtiles which is sqlite3 database, but the weight of the file is the same and even bigger ... What you would suggest?