Make UIImage a Circle without Losing quality? (swift)

Question

The image becomes blurry once applying roundImage: Making a UIImage to a circle form

extension UIImage
{
    func roundImage() -> UIImage
    {
        let newImage = self.copy() as! UIImage
        let cornerRadius = self.size.height/2
        UIGraphicsBeginImageContextWithOptions(self.size, false, 1.0)
        let bounds = CGRect(origin: CGPointZero, size: self.size)
        UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()
        newImage.drawInRect(bounds)
        let finalImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return finalImage
    }
}

Answer 1

try this one

let image = UIImageView(frame: CGRectMake(0, 0, 100, 100))

Answer 2

I recommend that you can use AlamofireImage ( https://github.com/Alamofire/AlamofireImage )

It's very easily to make rounded image or circle image without losing quality.

just like this:

let image = UIImage(named: "unicorn")!
let radius: CGFloat = 20.0

let roundedImage = image.af_imageWithRoundedCornerRadius(radius)
let circularImage = image.af_imageRoundedIntoCircle()

Voila!

Answer 3

Why are you using bezierpath ? Just set cornerradius for uiimageview .

If your image is larger than the imageview then you have to resize your image to your imageview size and then set cornerradius for that uiimageview .

It will work. Works for me

Replace the following line

UIGraphicsBeginImageContextWithOptions(self.size, false, 1.0)

with

UIGraphicsBeginImageContextWithOptions(self.size, view.opaque , 0.0)

Answer 4

Your issue is that you are using scale 1, which is the lowest "quality". Setting the scale to 0 will use the device scale, which just uses the image as is.

A side note: Functions inside a class that return a new instance of that class can be implemented as class functions. This makes it very clear what the function does. It does not manipulate the existing image. It returns a new one.

Since you were talking about circles, I also corrected your code so it will now make a circle of any image and crop it. You might want to center this.

extension UIImage {

    class func roundImage(image : UIImage) -> UIImage? {

        // copy
        guard let newImage = image.copy() as? UIImage else {
            return nil
        }
        // start context
        UIGraphicsBeginImageContextWithOptions(newImage.size, false, 0.0)

        // bounds
        let cornerRadius = newImage.size.height / 2
        let minDim = min(newImage.size.height, newImage.size.width)
        let bounds = CGRect(origin: CGPointZero, size: CGSize(width: minDim, height: minDim))
        UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()

        // new image
        newImage.drawInRect(bounds)
        let finalImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        // crop
        let maybeCrop = UIImage.crop(finalImage, cropRect: bounds)

        return maybeCrop

    }

    class func crop(image: UIImage, cropRect : CGRect) -> UIImage? {

        guard let imgRef = CGImageCreateWithImageInRect(image.CGImage, cropRect) else {
            return nil
        }
        return UIImage(CGImage: imgRef)
    }
}