SVG images in ODF would have an extra copy of PNG format, which makes the file size become large. Is it intentional? If yes, why?

This question is also asked in zh-tw forum.

Opening files with SVG images inside in LibreOffice and saving as ODT files, the file sizes became much more. Then the user found that under the Pictures folder of ODT files, all the SVG files had a copy of PNG format, which made the file size became much more than the original file.

The original files were made by Apache OpenOffice. In AOO it wouldn’t have a PNG copy.

Is this behavior intentional? Would anyone please tell us what it is for? Besides, is there any expert options to control this behavior, i.e., to control if a PNG copy is made or not?

The png version is included to help consumers, which are not able to read svg-images. For example Word got only recently the ability to read svg-images. Including different representations of the same content is explicitly allowed in file format for this purpose.

I cannot confirm your observation about Apache OpenOffice. I have got version 4.1.5 and it includes png-images too. And Word 365, which has an usable ODF export, includes a png-image as well.

I do not know any setting to suppress including png-images. If file size is really a problem for you, then you should write an enhancement request to provide means to save to a minimal file size.

Thank you very much.

Enhancement Request: