- LibreOffice https://www.libreoffice.org/ (It maybe works also with OpenOffice)
- Inkscape https://inkscape.org/
- A chart or a graph you want to export in high resolution
- 5-10 minutes
Nothing could be simpler...
First of all, if you are not working LibreOffice yet, then start LibreOffice Calc, import your data and generate the chart you like.
Once your chart is ready, right-click on it and select: Export as image, as displayed in the picture below.
You will then be invited to select where and how to save your image. The idea is to take profit of the vector format, so we are going to save our image as an SVG file.
Once saved, open the SVG file into Inkscape and you should see somehting like below.
Here you can still edit the picture as you want actually. If you changed your mind and wants to change your colors scheme or resize some elements. Everything is possible. For example here I just added outlines to the pie and its slices.
Then you can export in PNG in high resolution so that you make sure you don't lose quality like in the screenshot below.
High Resolution: 300 DPI export
Low Resolution: 60 DPI export
And after all if your communication support allows SVG files, I would advice you to just save a copy as Plain SVG and display the SVG directly. Like every modern browser supports SVG.
Plain SVG edited in Inkscape
Plain SVG from LibreOffice