Cut a UIImage into a circle

Question

I want to cut a UIImage into a circle so that I can then use it as an annotation. Every answer on this site that I've found describes creating an UIImageView, then modifying that and displaying it, but you cant set the image of an annotation to an UIImageView, only a UIImage. How should I go about this?

Answer 1

Xcode 11 • Swift 5.1 or later

edit/update: For iOS10+ We can use UIGraphicsImageRenderer. For older Swift syntax check edit history.

extension UIImage {
    var isPortrait:  Bool    { size.height > size.width }
    var isLandscape: Bool    { size.width > size.height }
    var breadth:     CGFloat { min(size.width, size.height) }
    var breadthSize: CGSize  { .init(width: breadth, height: breadth) }
    var breadthRect: CGRect  { .init(origin: .zero, size: breadthSize) }
    var circleMasked: UIImage? {
        guard let cgImage = cgImage?
            .cropping(to: .init(origin: .init(x: isLandscape ? ((size.width-size.height)/2).rounded(.down) : 0,
                                              y: isPortrait  ? ((size.height-size.width)/2).rounded(.down) : 0),
                                size: breadthSize)) else { return nil }
        let format = imageRendererFormat
        format.opaque = false
        return UIGraphicsImageRenderer(size: breadthSize, format: format).image { _ in
            UIBezierPath(ovalIn: breadthRect).addClip()
            UIImage(cgImage: cgImage, scale: format.scale, orientation: imageOrientation)
            .draw(in: .init(origin: .zero, size: breadthSize))
        }
    }
}

Playground Testing

let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"https://i.stack.imgur.com/Xs4RX.jpg")!))!
profilePicture.circleMasked

---

Answer 2

Make sure to import QuarzCore if needed.

 func maskRoundedImage(image: UIImage, radius: CGFloat) -> UIImage {
        let imageView: UIImageView = UIImageView(image: image)
        let layer = imageView.layer
        layer.masksToBounds = true
        layer.cornerRadius = radius
        UIGraphicsBeginImageContext(imageView.bounds.size)
        layer.render(in: UIGraphicsGetCurrentContext()!)
        let roundedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return roundedImage!
    }

Answer 3

UIImage extension:

extension UIImage {

    func circularImage(size size: CGSize?) -> UIImage {
        let newSize = size ?? self.size

        let minEdge = min(newSize.height, newSize.width)
        let size = CGSize(width: minEdge, height: minEdge)

        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
        let context = UIGraphicsGetCurrentContext()

        self.drawInRect(CGRect(origin: CGPoint.zero, size: size), blendMode: .Copy, alpha: 1.0)

        CGContextSetBlendMode(context, .Copy)
        CGContextSetFillColorWithColor(context, UIColor.clearColor().CGColor)

        let rectPath = UIBezierPath(rect: CGRect(origin: CGPoint.zero, size: size))
        let circlePath = UIBezierPath(ovalInRect: CGRect(origin: CGPoint.zero, size: size))
        rectPath.appendPath(circlePath)
        rectPath.usesEvenOddFillRule = true
        rectPath.fill()

        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return result
    }

}

Usage:

UIImageView:

@IBDesignable class CircularImageView: UIImageView {

    override var image: UIImage? {
        didSet {
            super.image = image?.circularImage(size: nil)
        }
    }

}

UIButton:

@IBDesignable class CircularImageButton: UIButton {

    override func setImage(image: UIImage?, forState state: UIControlState) {
        let circularImage = image?.circularImage(size: nil)
        super.setImage(circularImage, forState: state)
    }

}

Answer 4

Based on Nikos answer:

public extension UIImage {

func roundedImage() -> UIImage {
    let imageView: UIImageView = UIImageView(image: self)
    let layer = imageView.layer
    layer.masksToBounds = true
    layer.cornerRadius = imageView.frame.width / 2
    UIGraphicsBeginImageContext(imageView.bounds.size)
    layer.render(in: UIGraphicsGetCurrentContext()!)
    let roundedImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return roundedImage!
    }

}

//Usage

let roundedImage = image.roundedImage()

Answer 5

You can use this code to circle Image

extension UIImage {
func circleImage(_ cornerRadius: CGFloat, size: CGSize) -> UIImage? {
    let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
    UIGraphicsBeginImageContextWithOptions(size, false, 0)
    if let context = UIGraphicsGetCurrentContext() {
        var path: UIBezierPath
        if size.height == size.width {
            if cornerRadius == size.width/2 {
                path = UIBezierPath(arcCenter: CGPoint(x: size.width/2, y: size.height/2), radius: cornerRadius, startAngle: 0, endAngle: 2.0*CGFloat(Double.pi), clockwise: true)
            }else {
                path = UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius)
            }
        }else {
            path = UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius)
        }
        context.addPath(path.cgPath)
        context.clip()
        self.draw(in: rect)
        // 从上下文上获取剪裁后的照片
        guard let uncompressedImage = UIGraphicsGetImageFromCurrentImageContext() else {
            UIGraphicsEndImageContext()
            return nil
        }
        // 关闭上下文
        UIGraphicsEndImageContext()
        return uncompressedImage
    }else {
        return nil
    }
}}

Answer 6

All these answers were really complex for a straight forward solution. I just replicated my Objective-C code and adjusted for Swift.

self.myImageView?.layer.cornerRadius = (self.myImageView?.frame.size.width)! / 2;
self.myImageView?.clipsToBounds = true

Answer 7

I managed to answer my own question by finding a use of BezierPath!

if let xyz = UIImage(contentsOfFile: readPath) {
     var Rect: CGRect = CGRectMake(0, 0, xyz.size.width, xyz.size.height)
     var x = UIBezierPath(roundedRect: Rect, cornerRadius: 200).addClip()

     UIGraphicsBeginImageContextWithOptions(xyz.size, false, xyz.scale)
     xyz.drawInRect(Rect)
     var ImageNew = UIGraphicsGetImageFromCurrentImageContext()
     UIGraphicsEndImageContext()
     annotation.image = ImageNew
}

Answer 8

Xcode 8.1, Swift 3.0.1

My code will look like this:

let image = yourImage.resize(CGSize(width: 20, height: 20))?.circled(forRadius: 20)

Add UIImage Extension, then:

func resize(_ size: CGSize) -> UIImage? {
    let rect = CGRect(origin: .zero, size: size)
    return redraw(in: rect)
}

func redraw(in rect: CGRect) -> UIImage? {
    UIGraphicsBeginImageContextWithOptions(rect.size, false, UIScreen.main.scale)

    guard let context = UIGraphicsGetCurrentContext(), let cgImage = cgImage else { return nil }

    let rect = CGRect(origin: .zero, size: size)
    let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: rect.size.height)

    context.concatenate(flipVertical)
    context.draw(cgImage, in: rect)

    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}

func circled(forRadius radius: CGFloat) -> UIImage? {
    let rediusSize = CGSize(width: radius, height: radius)
    let rect = CGRect(origin: .zero, size: size)

    UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale)

    guard let context = UIGraphicsGetCurrentContext(), let cgImage = cgImage else { return nil }

    let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: rect.size.height)
    context.concatenate(flipVertical)

    let bezierPath = UIBezierPath(roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: rediusSize)
    context.addPath(bezierPath.cgPath)
    context.clip()

    context.drawPath(using: .fillStroke)
    context.draw(cgImage, in: rect)

    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return image
}

Answer 9

Swift 5.3, Xcode 12.2, Handles all imageOrientations

Based on answer Leo Dabus

Thanks, works perfectly! BUT only for images with imageOrientation .up or .down. For images with .right or .left orientation there are distortions in result. And from iPhone/iPad camera for original photos initially we get .right orientation.

Code below takes into account imageOrientation property:

extension UIImage {

    func cropToCircle() -> UIImage? {
    
        let isLandscape = size.width > size.height
        let isUpOrDownImageOrientation = [0,1,4,5].contains(imageOrientation.rawValue)
    
        let breadth: CGFloat = min(size.width, size.height)
        let breadthSize = CGSize(width: breadth, height: breadth)
        let breadthRect = CGRect(origin: .zero, size: breadthSize)
    
        let xOriginPoint = CGFloat(isLandscape ?
                                (isUpOrDownImageOrientation ? ((size.width-size.height)/2).rounded(.down) : 0) :
                                (isUpOrDownImageOrientation ? 0 : ((size.height-size.width)/2).rounded(.down)))
        let yOriginPoint = CGFloat(isLandscape ?
                                (isUpOrDownImageOrientation ? 0 : ((size.width-size.height)/2).rounded(.down)) :
                                (isUpOrDownImageOrientation ? ((size.height-size.width)/2).rounded(.down) : 0))
    
        guard let cgImage = cgImage?.cropping(to: CGRect(origin: CGPoint(x: xOriginPoint, y: yOriginPoint),
                                                     size: breadthSize)) else { return nil }
        let format = imageRendererFormat
        format.opaque = false
    
        return UIGraphicsImageRenderer(size: breadthSize, format: format).image {_ in
            UIBezierPath(ovalIn: breadthRect).addClip()
            UIImage(cgImage: cgImage, scale: format.scale, orientation: imageOrientation).draw(in: CGRect(origin: .zero, size: breadthSize))
        }
    }
}

Answer 10

swift 3 conform to MVC pattern create an external file

@IBDesignable
class RoundImage: UIImageView{


@IBInspectable var cornerRadius: CGFloat = 0 {
    didSet{
        self.layer.cornerRadius = cornerRadius
    }
}

// set border width
@IBInspectable var borderWidth: CGFloat = 0 {
    didSet{
        self.layer.borderWidth = borderWidth
    }
}

// set border color

@IBInspectable var borderColor: UIColor = UIColor.clear {
    didSet{
        self.layer.borderColor = borderColor.cgColor
    }
}

override func awakeFromNib() {
    self.clipsToBounds = true
}


}// class

call class in the IB on storyboard

set cornerradius as you please (1/2 of width if desire circle)

Done!

Answer 11

I am using RoundedImageView class, the problem facing is that when browse image from gallery the image not show in round or circle.. I simply change the properties of UIImageView/RoundedImageView -> view -> Content Mode -> Aspect Fillsee screenshot

Answer 12

The accepted answer by @Leo Dabus is good but here's a better approach ✅

import UIKit

public extension UIImage {
    /// Returns a circle image with diameter, color and optional padding
    class func circle(_ color: UIColor, diameter: CGFloat, padding: CGFloat = .zero) -> UIImage {
        let rectangle = CGSize(width: diameter + padding * 2, height: diameter + padding * 2)
        return UIGraphicsImageRenderer(size: rectangle).image { context in
            let rect = CGRect(x: padding, y: padding, width: diameter + padding, height: diameter + padding)
            color.setFill()
            UIBezierPath(ovalIn: rect).fill()
        }
    }
}

How to use

let image = UIImage.circle(.black, diameter: 8.0)

• Fewer code lines
• Ability to add padding
• Non-optional result