I've been tinkering with this for a while now and I think my brain has finally melted so hopefully somebody can help clear things up for me.
I have a photo app that manipulates images that are 2540x1778 @ 254ppi. For obvious reasons, when manipulating the image in the application we use a scaled down version (currently 500x349 @ 96ppi). The trouble I am currently having is upscaling text from the smaller image back to the full size image when it comes to saving, particularly taking into account the difference in resolutions.
Hopefully somebody can make this simple for me, or at least point me in the right direction.