Circular UIImageView in UITableView without performance hit?

I have a UIImageView on each of my UITableView cells, that display a remote image (using SDWebImage). I've done some QuartzCore layer styling to the image view, as such:

UIImageView *itemImageView = (UIImageView *)[cell viewWithTag:100];
    itemImageView.layer.borderWidth = 1.0f;
    itemImageView.layer.borderColor = [UIColor concreteColor].CGColor;
    itemImageView.layer.masksToBounds = NO;
    itemImageView.clipsToBounds = YES;

So now I have a 50x50 square with a faint grey border, but I'd like to make it circular instead of squared. The app Hemoglobe uses circular images in table views, and that's the effect I'd like to achieve. However, I don't want to use cornerRadius, as that degrades my scrolling FPS.

Here's Hemoglobe showing circular UIImageViews:

Is there any way to get this effect? Thanks.

Simply set the cornerRadius to half of the width or height (assuming your object's view is square).

For example, if your object's view's width and height are both 50:

itemImageView.layer.cornerRadius = 25;

Update - As user atulkhatri points out, it won't work if you don't add:

itemImageView.layer.masksToBounds = YES;

To Add border

self.ImageView.layer.borderWidth = 3.0f;

self.ImageView.layer.borderColor = [UIColor whiteColor].CGColor;

For Circular Shape

self.ImageView.layer.cornerRadius = self.ImageView.frame.size.width / 2;
self.ImageView.clipsToBounds = YES;

Refer this link

http://www.appcoda.com/ios-programming-circular-image-calayer/

Use this code.. This will be helpful..

    UIImage* image = ...;
    UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, 1.0);
    // Add a clip before drawing anything, in the shape of an rounded rect
    [[UIBezierPath bezierPathWithRoundedRect:imageView.bounds
                                cornerRadius:50.0] addClip];
    // Draw your image
    [image drawInRect:imageView.bounds];

    // Get the image, here setting the UIImageView image
    imageView.image = UIGraphicsGetImageFromCurrentImageContext();

    // Lets forget about that we were drawing
    UIGraphicsEndImageContext();

It works fine for me. :)

Here is a more up to date method in swift using IBDesignable and IBInspectable to subclass UIImageView

@IBDesignable class RoundableUIImageView: UIImageView {
    private var _round = false
    @IBInspectable var round: Bool {
        set {
            _round = newValue
            makeRound()
        }
        get {
            return self._round
        }
    }
    override internal var frame: CGRect {
        set {
            super.frame = newValue
            makeRound()
        }
        get {
            return super.frame
        }

    }

    private func makeRound() {
        if self.round == true {
            self.clipsToBounds = true
            self.layer.cornerRadius = (self.frame.width + self.frame.height) / 4
        } else {
            self.layer.cornerRadius = 0
        }
    }

    override func layoutSubviews() {
            makeRound()
    }
}