iOS: Image get rotated 90 degree after saved as PNG representation data

Swift 4.2

Add the following as UIImage extension,

extension UIImage {
    func fixOrientation() -> UIImage? {
        if self.imageOrientation == UIImage.Orientation.up {
            return self
        }

        UIGraphicsBeginImageContext(self.size)
        self.draw(in: CGRect(origin: .zero, size: self.size))
        let normalizedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return normalizedImage
    }
}

Example usage:

let cameraImage = //image captured from camera
let orientationFixedImage = cameraImage.fixOrientation()

Explanation:

The magic happens when you call UIImage's draw(in:) function, which redraws the image respecting originally captured orientation settings. [link to docs]

Make sure to call UIGraphicsBeginImageContext with image's size before calling draw to let draw rewrite the UIImage in current context's space.

UIGraphicsGetImageFromCurrentImageContext lets you capture whatever is the result of the redrawn image, & UIGraphicsEndImageContext ends and frees up the graphics context.

Starting with iOS 4.0 when the camera takes a photo it does not rotate it before saving, it

simply sets a rotation flag in the EXIF data of the JPEG.If you save a UIImage as a JPEG, it

will set the rotation flag.PNGs do not support a rotation flag, so if you save a UIImage as a

PNG, it will be rotated incorrectly and not have a flag set to fix it. So if you want PNG

images you must rotate them yourself, for that check this link.