Thread: Convert garmin .img pseudo-NT to non-NT? I know it's possible, but how?(SOLVED!!!)

I've gone through a lot of forums, and i see that GPSMapEdit 1.0.66.7 can open NT formats (based on the experience of users). Not a version less or more, but this exact version. Said it's some kind of bug that processes the img file. But if your are lucky to have GPSMapEdit 1.0.66.7, kindly share, because I'm quite sure its of the internet. I have tried and tired...

Cheerio

Originally Posted by Pdogz2009

I've gone through a lot of forums, and i see that GPSMapEdit 1.0.66.7 can open NT formats (based on the experience of users).

These users are wrong and mislead you.
The version 1.0.66.7 of GME is able to parse only pseudo-NT format, not the true NT format.

Updated [Only registered and activated users can see links. ] with a mini-TUTORIAL

The answer is No.

Don't confuse the way the maps are packed (not compressed) in the img file with the format of the map.
img files are containers, they can embed one or more maps.
There are two ways to pack maps in an img:
- standard packing: all sub-files (TRE, RGN, LBL, NET, NOD, DEM, TYP, MDR, SRT, MPS, MD2, TRF, QSI, IDX, MMR, SID, TDB, etc.) are put together, one after another, in the img file.
- GMP packing: for each tile, the 9 main subfiles (TRE, RGN, LBL, NET, NOD, DEM, MAR, MET(1), MET(2)) are packed in a container named GMP, then, all the GMP files and the other subfiles (TYP, MDR, SRT, MPS, MD2, TRF, QSI, IDX, MMR, SID, TDB, etc...) are packed in the img container.

It is not difficult to convert a mapset packed in one method to the other method (when possible but not always possible as we will see later).

The format of the map is another totally different concept: it is how data is stored inside each subfile (RGN, NET, NOD etc..). In NT format, points, polygons and polylines coordinates are usually Huffmann compressed (but not necessarily) and, most importantly, all routing data in the NET and NOD subfiles is fundamentally different from the data stored in the NET and NOD subfiles of the old format. . Moreover, the new format (NT format) has made it possible to develop new functionalities (such as point addressing and others...) which did not exist in the old format. So converting maps in NT format to the older format is impossible, unless you lose a lot of data and functionalities and, again, assuming someone is able to parse the data in the format subfiles NT.

So converting map in Old Standard from standard packing to GMP packing is easy (it's what someone called a pseudo-NT map but it has nothing to do with the NT format!) and also for the reverse but converting NT Format to Old Format is impossible.

Furthermore, maps in the Old Format can be packed either in standard packing or in GMP packing but maps in NT Format are necessarily packed in GMP packing: NT Format is incompatible with the standard packing.