Specialized GPS/GIS converters like the Total GIS converter can be used to export a variety of map / spatial formats as common pictures, typically as TIFF but also as JPEG images. Used mainly for sharing maps as pictures, to reduce the file size etc. However the resulting image usually cannot be used in GIS software anymore.
Convert GPS Pathfinder Office geoid grid file to JPEG bitmap image format.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert dgf to jpg on Windows
A converter that is able to transform various GIS file formats
Convert from dgf 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.