Scan data or subdivision border cleaning

Hi,

I search help for scan data edge cleaning.
It is possible to project scan border on a curve in normal. I mean for exemple, if I have a hole in a scan, I draw a circle and I project the the free border on the curve.
I find the boring way to do it point by point, but i want to know if it’s possible with a command and maybe with historic.

Thank’s in advance,
Fred