@Ibralebbe Ab...
It depends on what kind of image file you want...
If you want a png or jpeg, etc you can download it from the [openstreetmap.org site][1] and use the share link at the right side. See also the 'cartinus' link this [link to a previous question.
![image][2]
question][2] for other relevent points.
![image][3]
Instead, if you want .img type map file to load on to a Garmin gps you don't download directly from the link above but from one of the sites that convert the osm data into a Garmin suitable map. See these [Garmin osm map download sites][3] sites][4]
I suggest that the first time you do this that you do a small local area such as the local suburb to acquaint yourself with the process. The [BBBike][4] [BBBike][5] "Select your own region" is good for this.
As a beginner using a Garmin, I found this [DC RAINMAKER][5] RAINMAKER][6] site to be helpful. The process is similar for most models.
[1]: http://www.openstreetmap.org
[2]: https://help.openstreetmap.org/questions/21192/error-export-load-average-on-the-server-is-too-high-at-the-moment
[3]: http://help.openstreetmap.org/upfiles/Screen_Shot_2014-06-23_at_2.43.26_pm_1.png
[3]: [4]: http://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/Download
[4]: [5]: http://download.bbbike.org/osm/
[5]: [6]: http://www.dcrainmaker.com/2013/05/download-garmin-705800810.html