On iMac I need to run java to run mkgmap so put
Java -jar in front of the rest of the mkgmap command.
In my case i need to use the path to java and mkgmap too.
/Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java -jar /Applications/mkgmap-r3132/mkgmap.jar --gmapsupp , etc --output-dir=/Users/xxx/Documents/xxx/
You might get problems if both img comes form the same map. This could mean that some parts have the same name - typ file or index file. Combining could remove duplicate parts, reducing some functionality.
It doesn’t work for me. Combining 2 img removes search index form second img.
I have my own map created with mkgmap. In Mapsource I select 2 sets of tiles and generate 2 img, then I combine both with mkgmap. Size of output img is different depending on order of input img, because removed indexes are different size.
I’m not sure if this error is enough to explain size difference that OP has observed (even assuming that all sizes are in MB).
I have tested mkgmap with options provided by OP. If you add --index, then shouldn’t you add --code-page too?
Edit: adding options --index doesn’t change mkgmap behavior. You would have to split img into tiles and then merge them back, to get new index. And in this case you should provide FID too. Code page is detected correctly.
OSM Combiner works best with the osm_generic_tiles.zip files, because they contain the necessary files for creating the overview map, but it can also use gmapsupp.img files. In the latter case it uses your GmapTool to split the files.
When creating the combined map with mkgmap it sets the following options:
area-name, draw-priority, latin1, code-page, show-profiles, net, route, product-id, index, tdbfile, family-name, family-id, series-name, description and overview-mapname