I believe you could recreate this for knitting by doing a brioche stitch for the bottom of the hat and switching to a k1, p1 rib for the top. The top in this picture is smaller than the body to allow it to conform to the shape of your head. When you're about a half inch from the finish at the the top, your decreases will be: First row, k2 tog, p2 tog all around. Second and third row, k1, p1 around. Fourth, k2 all around. Fifth, if needed, k2 all around. Draw through remaining loops, fasten off. Hide ends. This set of decreases comes out to about half an inch. You will want to do the math and figure out where you want to start with the k1,p1 rib. The hat length depends on what you want. Here in Wisconsin, we want hats that cover the ears. That will be about 7 1/2 to 8 1/2 inches. The ribbing would start, I believe, about 3/4 of the length you want your hat. I'd suggest a size 7 or 8 needle with a cast on about 100. Been a while since I've done Brioche. Is this an even number cast on or a multiple of 3? Does anyone remember?