Geography maps or similar GIS files are often exported as TIFF graphics (.tif, .tiff). This can be usually done in a GIS software for the own default formats. For generics formats, you can use dedicated converters.
Convert Geography Markup Language to Aldus Tagged Image File Format (TIFF) bitmap image.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert gml to tiff on Windows
A converter that is able to transform various GIS file formats
Convert from gml file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.