How to crop UIImage on oval shape or circle shape?

Please give ideas for how to crop UIImage on oval shape or circle shape. Please share your ideas.

#import <QuartzCore/QuartzCore.h>

CALayer *imageLayer = YourImageview.layer;
        [imageLayer setCornerRadius:5];
        [imageLayer setBorderWidth:1];
        [imageLayer setMasksToBounds:YES];

by increasing radius it will become more round-able.

As long as the image is a square, you can get a perfect circle by taking half the width as the corner radius:

[imageView.layer setCornerRadius:imageView.frame.size.width/2]; 

You also need to add

[imageView.layer setMasksToBounds:YES];

Swift 4.2

import QuartzCore

var imageLayer: CALayer? = YourImageview.layer
imageLayer?.cornerRadius = 5
imageLayer?.borderWidth = 1
imageLayer?.masksToBounds = true