You've not told us where the photo/document is to start with. If it's an email attachment it will only be in a temporary folder (as suggested by Tuvok) and you won't be able to save a modified version of the file to that location.
If the program you're using to edit the file has a 'Save As' option (rather than just 'Save'), as most programs do, you can use that to choose a permanent location for the modified file. However my own preferred method would be to save the email attachment to a permanent location on my hard drive first, and then open it from there.