Hello:

Thank you very much for your replies.

Pilou, I gained some area with your piece of advice. I tried the program that you reccommended and I can't manage to get sattisfying results. My image is from a boat with large and thin lines, and also I'm a little dummie with computers.

Michael, that was wonderful. Thank you very much indeed. I tried it and it works perfectly.
I have just tried 3560x3560 and it also worked.

Thanks and regards.

Alberto