I started learning python to address this very issue(only having HTML experience previously). We backup our sheets to sharepoint. The problem we came across with backing up is that smartsheet just drops all the images into a single zip file and there isn't a way to know what row they originally went to. Therefore programming some thing to download separately with row names or modify the images in place and adding the row name.
I've managed to access the API and download the images but, I can't get the row numbers be on the image files.