As GIF export format has support for transparent background, if it is not too difficult to implement, could you consider adding transparency support also for the PNG export format. I think this would be a welcome feature addition to LibreOffice as PNG is otherwise more advanced format.
Checked with LO 3.5, currently no support for transparency in .png Setting Status to NEW
@devseppala@gmail.com: Please excuse me for having overlooked your report. Marking this one as DUP because more details in later report. *** This bug has been marked as a duplicate of bug 50814 ***