This is great and works! Processing a large amount of data in the background representing the final image and save to 'path' is my step one. The image (img1) is displayed (and saved).
When I come back later, I apply another process step on the displayed image generating a new image. Meanwhile I don't remember where I saved img1 (my problem, but ... ) but the new image should also be saved in the same location as img1. That is where I did run into the issue which is now solved! Thank you!