How to determine map type according to w3i

I have read the "Inside w3m/w3x files" document and now, I still cant tell deferences between w3m and w3x files according to a war3map.w3i file.

I know there are something new in w3x, but where is the main deferences in w3i file that determine the map type obviously?

The very first int (the w3i version) can be used to determine the type.
It's currently 18 for w3m and 25 for w3x files.

New in the TFT format are the values for terrain fog, global weather, custom sound and light environment and water tinting as well as the random item tables at the end of the file.

I found it! Thank you!