Maps n Trax can import many plain image files (such as JPEG and PNG) without any special procedures other than what is described in the section about importing.  However, maps imported this way will not be georeferenced (calibrated) and will take a long time to import as they are tiled during import (and sometimes tiling can fail during import if there is not enough RAM available).

There are three aspects to preparing maps to work better in Maps n Trax which should all be done on a desktop or laptop computer before downloading/uploading to Maps n Trax:

• Georeferencing – Defining the coordinate system (spatial reference system, including projection) AND the geographical area that the map covers in a standardised way the Maps n Trax can interpret and use.
• Warping – Producing a version of a map image in a different projection to the original image.  Maps n Trax displays all maps in the standard iOS mapping projection of WGS84/Spherical Mercator.
• Tiling – Splitting a large image into smaller image tiles for several different zoom scale versions of the image.

All of these are optional depending on the map image file being imported and the features that are required for it within Maps n Trax.  Using a map that is not georeferenced in Maps n Trax is very limiting, however, as it can only be viewed without any location related functionality and cannot be zoomed in or out.

Note that georeferencning can be done within Maps n Trax itself after import, but it is highly recommended to do it on the desktop before import for better results.  For georeferencing after import, see Atlas, Map and Sheet Editors.

If an image is not tiled before import, it will be automatically tiled during import.  This can take a very long time and can fail due to the high RAM requirements of the process.  Processing large images requires a lot of RAM and CPU power and is therefore unsuited to small mobile devices.  Tiling on the desktop before import is highly recommended.

Maps that are not in WGS84/Spherical Mercator projection when imported into Maps n Trax will be warped to Spherical Mercator projection automatically during import if possible.  This will only occur for correctly georeferenced images.  If the images cannot be warped they will often work OK but will be less accurate for location features.  In some cases the inaccuracy would be so small as to be insignificant, but in other cases it would be intolerable, depending on how different the projection is to WGS84/Spherical Mercator for the region covered by that map.

There are several options available for georeferencing, warping and tiling map images.  It is recommended to use MapTiler (Mac, Windows, Linux) or MAPC2MAPC (Windows) to prepare maps as they provide the easiest methods and can do the georeferencing, warping and tiling all in one procedure.