Can anyone has an idea how to check if an image has fiscal stamp?
Below I have 2 invoices: one with customer stamp, one without it.
I was thinking maybe some node to count the pixels from an image and what is higher than average it means it has the stamp.
This is an interesting problem, I like your initial approach, however you could try improving it by turning the image into binary using Global Thresholder, then experiment with the nodes: Fill Holes, Morphological Image Operations.
Take a look at the prototype workflow I build: