How to rotate image in Swift?

Question

I am unable to rotate the image by 90 degrees in swift. I have written below code but there is an error and doesn\'t compile

  func imageRotatedByDegrees(old         


        

Answer 1

set ImageView image

ImageView.transform = ImageView.transform.rotated(by: CGFloat(M_PI_2))

Swift 5

ImageView.transform = ImageView.transform.rotated(by: .pi)        // 180˚

ImageView.transform = ImageView.transform.rotated(by: .pi / 2)    // 90˚

ImageView.transform = ImageView.transform.rotated(by: .pi * 1.5)  // 270˚

Answer 2

In Swift 4.2 and Xcode 10.0

dropDownImageView.transform = dropDownImageView.transform.rotated(by: CGFloat(Double.pi / 2))

If you want to add animation...

UIView.animate(withDuration: 2.0, animations: {
   self.dropDownImageView.transform = self.dropDownImageView.transform.rotated(by: CGFloat(Double.pi / 2))
})

Answer 3

You can first set your image in imageView and rotate get your image in imageView

Here:

let customImageView = UIImageView()
customImageView.frame = CGRect.init(x: 0, y: 0, w: 250, h: 250)
customImageView.image = UIImage(named: "yourImage")

customImageView .transform = customImageView .transform.rotated(by: CGFloat.init(M_PI_2))
var rotatedImage = UIImage()
rotatedImage = customImageView.image!

Answer 4

If you just don't want specific rotation and like to use all orientations one by one.

func rotateImage() -> UIImage {
    let newOrientation = Orientation(rawValue: self.imageOrientation.rawValue + 1) ?? UIImage.Orientation(rawValue: 0)
    return UIImage(cgImage: self.cgImage!, scale: self.scale, orientation: newOrientation!)
}

Answer 5

You can use the code below for Swift 3:

extension UIImage {

func fixImageOrientation() -> UIImage? {
    var flip:Bool = false //used to see if the image is mirrored
    var isRotatedBy90:Bool = false // used to check whether aspect ratio is to be changed or not

    var transform = CGAffineTransform.identity

    //check current orientation of original image
    switch self.imageOrientation {
    case .down, .downMirrored:
        transform = transform.rotated(by: CGFloat(M_PI));

    case .left, .leftMirrored:
        transform = transform.rotated(by: CGFloat(M_PI_2));
        isRotatedBy90 = true
    case .right, .rightMirrored:
        transform = transform.rotated(by: CGFloat(-M_PI_2));
        isRotatedBy90 = true
    case .up, .upMirrored:
        break
    }

    switch self.imageOrientation {

    case .upMirrored, .downMirrored:
        transform = transform.translatedBy(x: self.size.width, y: 0)
        flip = true

    case .leftMirrored, .rightMirrored:
        transform = transform.translatedBy(x: self.size.height, y: 0)
        flip = true
    default:
        break;
    }

    // calculate the size of the rotated view's containing box for our drawing space
    let rotatedViewBox = UIView(frame: CGRect(origin: CGPoint(x:0, y:0), size: size))
    rotatedViewBox.transform = transform
    let rotatedSize = rotatedViewBox.frame.size

    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize)
    let bitmap = UIGraphicsGetCurrentContext()

    // Move the origin to the middle of the image so we will rotate and scale around the center.
    bitmap!.translateBy(x: rotatedSize.width / 2.0, y: rotatedSize.height / 2.0);

    // Now, draw the rotated/scaled image into the context
    var yFlip: CGFloat

    if(flip){
        yFlip = CGFloat(-1.0)
    } else {
        yFlip = CGFloat(1.0)
    }

    bitmap!.scaleBy(x: yFlip, y: -1.0)

    //check if we have to fix the aspect ratio
    if isRotatedBy90 {
        bitmap?.draw(self.cgImage!, in: CGRect(x: -size.width / 2, y: -size.height / 2, width: size.height,height: size.width))
    } else {
        bitmap?.draw(self.cgImage!, in: CGRect(x: -size.width / 2, y: -size.height / 2, width: size.width,height: size.height))
    }

    let fixedImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return fixedImage
}

Answer 6

In one line:

rotatedViewBox.transform = CGAffineTransform(rotationAngle: CGFloat.pi/2)