OK, having played around with it a little bit on a mac you could try to do this:
If you want to keep using the photos in Evernote:
- Open Evernote
- Select a note containing the photos you want to move to Tropy
- Drag each photo into Tropy (this will create an item for each photo)
- When you have a transcription of the photo, select the photo in Tropy and copy/paste the transcription into the notepad.
- When you have moved all the photos of the Evernote entry this way, select the corresponding items in Tropy and right click -> merge them into a single item.
If you move the photos this way, the original photos will stay where Evernote keeps them; this may not be ideal. You can add an extra step and make new copies of your photos. First create a folder where you want to keep all the photos. Then, instead of dragging the photos from Evernote into Tropy directly, drop them in the folder you created (this creates a copy), then drag the photo from the folder into Tropy.
Obviously this is still moving each photo manually so it may not be feasible to do for your entire library, but it's probably easier to do this way than starting from scratch.