I think http://graner.name/nicolas/nombres/bibibinaire.php http://graner.name/nicolas/nombres/bibibinaire.php has the original image, and there single-1 numbers

I think http://graner.name/nicolas/nombres/bibibinaire.php http://graner.name/nicolas/nombres/bibibinaire.php has the original image, and there single-1 numbers look quite different. It seems to me that the original idea was that corners and non-curly ends of the curve are where 1s are.