Hi,
I attach a vi that takes the front panel image and saves it in a JPEG file.
You can set the portion of your front panel image to save on disk.
I did not connect a vi reference, in this way it acts on the actual vi, but this can obviously changed.
In my example I used 8-bit pixel depth, you can easily change it to 24, remember in this case to connect the proper terminals on the functions.
Good luck,
Alberto