This is ultimately to scale the images to fit correctly in an advanced PDF

if you find out a way to do this, i would be super interested - but i tried every possible thing I could think of and just couldn't do it. it maybe could have been done client-side via dom manipulation like you said, but we have a common use case where images would be uploaded via mobile app so that wouldn't work. in the end, our conclusion was jsut to tell the client we'll pick a standard resize amount that will hopefully cover most images, and they have to view and verify all PDFs to see that the image looks ok (not too large or too small); if it is too large/small, they can edit a custom field which the PDF pulls from to resize it.