Feather alpha edges

[Feraud]

Hi.
I need to blur the alpha edges of an image, but only the edges not the whole image. I’ve been searching for something like that, but no luck. Any idea?
Thanks

[AlphaOne (Raymond)]

Dialate/Erode node with a blur node.

[Feraud]

I’m afraid my first tries were wrong… once you confirm it could work I think I get a way to use it to get what I wanted. I share how I used it

Thank you for the help