About image compression?

[AnnA]

I have a slideshow with photos in medium compression. If I open the slideshow
and add some new pages - will PPT perform a new compression om ALL PHOTOS or
just the added ones?

For instance when opening a JPG in Photoshop and re-saving it several times
causes a loss in image quality on every save. Is there a similair effect in
PPT that will cause all my includes images in the slide show to get lesser
and lesser image quality?

Thanks !

 

[Echo S]

Your images shouldn't receive a lesser quality unless you change the
compression settings. Leave them at medium, and you should be okay.

IIRC, PPT uses PNG internally, and it is a lossless format.