Set quality/compression of images in PDFs?

[Ben Rubinstein]

Is there any way to control the quality/compression of images in PDFs 
generated by LiveCode?

Putting a 1MB JPG on a card, and printing from the rect of the image to the 
page rect, makes about a 6MB PDF file. Changing the jpeg quality of the input 
JPG seems to make no difference.

Replacing the image with one that's been scaled 50%, and is 500KB, makes a 
2.5MB PDF.

What - if anything - can be done to reduce the filesize of a PDF created by 
"open printing to pdf"?

TIA,

Ben