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.
.

[nehavilash]

To easily compress images for your presentation, you can use the Minimize Presentation tool in Impress as suggested. Alternatively, you can pre-optimize your pictures using online tool like Image Compressor before adding them to the slides, ensuring smooth performance and smaller file sizes.

[MrProgrammer]

Ampulex's signature is OpenOffice 4.1.7 on Mac OS. A web search finds that MacOS provides a batch image modification tool:

How to Use macOS SIPS to Batch Resize Images
MacOS image manipulation with sips
sips: Scriptable image processing system
Converting Image File Formats with the Command Line and sips
Use sips to quickly, easily—and freely—convert image file

If this solved your problem please go to your first post use the Edit ✏️ button and add [Solved] to the start of the Subject field. Select the green checkmark icon at the same time.

[robleyd]

Hopefully Ampulex has resolved the problem by now as the original post was over four years ago.