The InsideScan plugin for scanning can do this too. It is quite broad in its ability.
So what I understand from this is that there's no way for FileMaker Pro to do this natively, I'd need a 3rd-party plug-in. Dang. I was hoping FMP12's new thumbnail capability for container fields would do the trick, but apparently all it does is store images 1/4, 1/16, and 1/64 the size of the original, so it doesn't have to push more bits than necessary down the wire to fill the available space in the target display. What I NEED it to do is store images in a fixed size that will EXACTLY fill the space in the target display.
Well, off to the suggestion box again, I guess.
Richard, why not size the images to exactly what you need them to be before you input them
I'm so used to FileMaker doing everything I want it to do that I'd already pulled in a couple of hundred images from all over the web before it dawned on me that this was something it COULDN'T do.
But I may just buckle down and do it that way. Yay for GraphicConverter, the best piece of shareware EVER!
Have you looked at the new function in FM12:
? store your original, but display how you want. Proportions are maintained, of course.
-- sent from my iPhone4 --
You may not consider this idea "native FileMaker," but perhaps you could do it with Perform Applescript and do shell script using sips.
sips -z 144 240 image.jpg
First you'd have to export the file to a known location, resize it, then bring it back into the database (maybe using a second container field).
There are also some web services that can resize an image, but my Web Viewer powers are too limited to help make that work.