How to export to PDF without changes of images?

[v_mil]

Dear All!

I have a document with different images: some of them are in PNG, other are in JPG with different quality from 10 to 95 %. Export to PDF with “Lossless compression” since version 6.4.4.2 converts all images to PNG. The result is very huge. “JPEG compression” requires the “Quality” setting. Set it to the same quality of all images is impossible due to the nature of the images. A higher quality provides a huge result. A lower quality makes some images unreadable.

How to export to PDF keeping the original images (at least, PNG, JPG) without changes?

With best regards.
Viktor.

[LeroyG]

@v_mil,

While exporting to PDF, have you selected Reduce image resolution?

A value of “300 DPI” is enough for printing.

Edit your question if you want to add more information; also can comment an answer. Do not use Add Answer to comment.

[v_mil]

Thank you! The images are already prepared with the appropriate resolution - 300 dpi at actual size. When I exported documents with previous versions of LO, setting “Lossless compression” preserved the image format and quality. When I exporting the same document now, the size of PDFs is two time greater! Openning the last ones by InkScape and extracting the images shows that they are in png disregarding the original format.

[LeroyG]

@v_mil,

I created a sample file with two images. The first imported image is .jpg, the second is .png. I exported it as PDF (LibreOffice 6.3.6.2 (x86); OS: Windows 6.1).

Opening the file code I can see that images code are different (for .jpg is JFIF).

Can you download the sample file, export with the same options and share the resulting PDF? To share the file, edit your question and use the paper clip.

By the way, importing the file in Inkscape I can’t see differences between the .jpg and the .png.

[v_mil]

Many thanks! Sorry for the late answer. I exported them to PDF. The PDF was openned by InkScape and fully ungroupped. After that, both images was extracted. Both are PNG (The first image, The second image). The size of the first image is greater because of JPEG artefacts in the original one.
In the version 6.3.6.2. there are no problems. The problem appears since 6.4.5.2.

[v_mil]

LibreOffice 7.0.0.2 has the same problem. Also, different versions of LibreOffice installed “in parallel” (https://wiki.documentfoundation.org/Installing_in_parallel/Linux) export to PDF without the text “png” and “jpg”. So, installing old version in this way is not a workaround.

[v_mil]

After upgrading the system now it works normally, if installen normally, not “In parallel”. Now PDF files have enough size.