GeoGebra mathematics software allows users to export their documents (.ggb) or some of their parts as pictures (either raster PNG or vector SVG). This is usually done when exporting graphs or geometry. You can get the program for free, so try it out.
Convert GeoGebra document to Portable Network Graphic.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert ggb to png on Windows
A free mathematics software
Convert from ggb 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.