Batch compression of pictures

[Ampulex]

Dear

I am a rookie on impress and any other presentation software. I try to find an answer online but couldn't find anything.

What i did is I downloaded pictures from a cloud and inserted them in impress. Most are 3 to 4 pictures a slide. Now i start to notice the software runs slower because of the huge pictures.
I can see the percentages of scaling are 8 to 20%. Probably the pictures also have a high resolution. Is there a way to crop the pictures to that scaling and lower the resolution? I presume the pictures i use are the original format/size buts called when i insert them in impress?

Thank you for the support.

[RoryOF]

/Tools /Minimise presentation will make a copy of your presentation with the pictures reduced and embedded.

[Ampulex]

Thank you Rory that's exactly what i was looking for. 200MB to 5.5MB with print optimized and with screen optimized as little as 0.4MB

[RoryOF]

I normally would make a presentation using pictures as they come to hand, but before presentation, after the file was complete, I would minimise the file and use the minimised version for the actual event. Ideally one should optimise all picture before including them in the presentation; this was fine when one had projectors only of limited resolution, but now one can have projectors of advanced resolution and it can be good to remake a file targetted for those.
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