Powerpoint: compress or downsample large images/graphics I'm using Powerpoint 2011, and I'm not able to find an option to easily downsample or compress images to produce a smaller output PPTX or PPT file. 

I don't need the high resolution in some of the images in the slide, so the downsampling wouldn't hurt, but the option just does not seem to exist in the Mac version of Powerpoint (the Windows version has this feature.)

Is there any way I can compress the image and graphics sizes while saving or exporting a Powerpoint file in Mac? Or do I have downsample each of the individual images?
In PowerPoint 2011, you can use File > Reduce File Size to auto-downsample images. The dialog gives you a few options for quality: