Introduction.

If this is your first attempt to create your own Garmin map, youíve come to the right place.

This tutorial assumes no prior knowledge from the reader about what makes a digital map and how the map making process works. If you already know about:

Then you can skip ahead to the overview of how to make a map using .

A map suitable for uploading directly to a Garmin GPS needs to be in Garmin image file format, held in a .img file. This file format is proprietary to Garmin. Luckily for us amateur map makers, the format was decoded by a Polish software developer who wrote an application called cGPSMapper to generate Garmin image files.

The only problem is that cGPSMapper isnít a graphical application. It takes as its input a text file in what has become known as Polish Map Format - traditionally held in a .mp file. Itís called Polish format simply because the person who invented it was Polish. The .mp file type stands for Mapa Polska (I think thatís right), which is Polish Map in Polish.

It is possible to create a map by writing a Polish format text file by hand, using a text editor, then using cGPSMapper to convert your .mp file into a Garmin map image. This is only a practical proposition for the very smallest of maps because you would have to type in the coordinates of every single map item, every bend in every road and every point on every region boundary. For anything but the most trivial of maps this would take the best part of forever. You would also have to learn the slightly arcane format in which Polish format maps are expressed.

Luckily thatís not necessary. Applications like allow you to draw a map on your PC screen. When itís finished will create the Polish format map file for you. The cGPSMapper application is still necessary to convert your Polish format file to a Garmin image file but you donít need to know how to operate the cGPSMapper application. It just has to be on your computer somewhere where can find it. will take care of all the nitty-gritty, calling cGPSMapper as necessary.

Another thing you need to understand is the difference between items which are part of your digital map and user-defined items like waypoints. For an explanation of the distinction, click here.

OK, with that understood you are ready to start. Where do you start? Probably the easiest way is to start with a computer image of a conventional map of the area you are interested in. This could be obtained by scanning in a paper map or maybe you could download a suitable image from the internet. This tutorial assumes you have procured a suitable image. We are now ready to proceed to the first lesson...


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