Description: I have a document with lots of images and need compression. When I open the Image compression dialog, I get a 80% JPEG image quality as a default (which I find a bit low) but the help manual says : "The default value of 90 produces very good results and significant image data size reduction." 90 would be perfect. Is there a way to have the dialog box to behave as per the documentation ? Steps to Reproduce: 1.Insert an image into document 2.Right-click and select "compress" 3.See that the default JPEG compression is 80% Actual Results: See that the default JPEG compression is 80% Expected Results: The default JPEG compression should be 90% as mentioned in documentation. Reproducible: Always User Profile Reset: No Additional Info: [Information automatically included from LibreOffice] Locale: en-US Module: TextDocument [Information guessed from browser] OS: Mac OS X (All) OS is 64bit: no
I confirm it with Version: 7.3.1.2 (x64) / LibreOffice Community Build ID: 9fff0292474d6d0bf5df787b512c71d9ac4bc98e CPU threads: 4; OS: Windows 10.0 Build 19044; UI render: Skia/Raster; VCL: win Locale: de-DE (de_DE); UI: de-DE Calc: CL I don't know, if help is wrong or dialog cc: Design-Team
Yes, let's go with 90 (it's not percent but some arbitrary value between 1 and 100). Code pointer: * QualityMF in svx/source/dialog/compressgraphicdialog.cxx * quality-adjustment-spin/quality-adjustment-scale in svx/uiconfig/ui/compressgraphicdialog.ui (but those will be overwritten anyway)
I changed the default to 80% which make the images smaller in file size, but you can't see it with your eyes. In addition you click on image compression, so the user want smaller file size. If you use 90% the sizes are way bigger. The difference between 90% and 80% are ordinary factor 10.
(In reply to andreas_k from comment #3) > I changed the default to 80% ... For bug 128658. So rather update the documentation? Franz, can you follow Andreas' arguments?
(In reply to Heiko Tietze from comment #4) > (In reply to andreas_k from comment #3) > > I changed the default to 80% ... > > For bug 128658. So rather update the documentation? Franz, can you follow > Andreas' arguments? Hi all, my target is to print the document so I'll definitely stick with the 300 dpi as mentioned in bug 128658. I will print a test file with 90 and 80 images, just to check in the next few days. I'll update if I found out that there is a noticeable difference or just to confirm Andrea's argument. I suppose Andrea's right so that mean documentation needs to be updated. I'll keep you informed.
Did a test file (see attached file) and can confirm that on screen you can't tell the difference between the two compressions with your eyes. Also image sizes are for a 17cm x 12,75cm photo : - 80 % - 318 kB - 90 % - 462 kB I'll keep you updated with test print in the next few days. Just an additional quick comment... The interactive "export as PDF" dialog uses JPEG 90% 300 DPI as a default for image compression. There is some kind of inconsistency here.
Created attachment 178609 [details] File with a 80% and a 90% compressed photo Can't notice a difference with your eyes between the two compressions. Original image from wikimedia commons : https://commons.wikimedia.org/wiki/File:Apodemus_sylvaticus_(Sardinia).jpg