You can import PNG graphics to LibreOffice Draw and save it on OpenDocument Drawing format. It might also be possible to use one of the on-line conversion services and perform the same conversion there.
Convert Portable Network Graphic to OpenDocument drawing.
We have found 2 software records in our database eligible for .png to .odg file format conversion.
Multiplatform software - convert png to odg on any platform
LibreOffice Draw is a useful software tool for creating various drawings, diagrams and other simple graphics. It's an open source program that comes as an integral part of LibreOffice suite.
Convert from png file
to odg file
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned png to odg. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Inkscape is vector graphics editor that using with W3C standard Scalable Vector Graphics (SVG) file format. Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.)