objective c - Create UIImageView with circle border iOS -

i trying create border around uiimageview perfect circle using cornerradius. i've looked @ says code correct, returns more of diamond shape. (i've imported quartzcore, not sure needed to)

image.layer.cornerradius = (image.bounds.size.width/2); image.layer.borderwidth = 5; image.layer.bordercolor = [uicolor whitecolor].cgcolor; 

any ideas?

have tried add:

image.layer.maskstobounds = yes; 

another thing: width of image equal height?