Opens a dialogue box in order to load a picture file from disk (BMP, GIF, TIF, PNG or JPEG).

Picture files are associated with a properties file named with the picture followed by a .DAT extension. The file format of the map properties .dat file is described in 'Map file .dat'.

When the properties file is not found, the file is considered as a user picture that can be scaled manually (see Import and scale user pictures).