Last active
February 4, 2024 15:00
-
-
Save schickling/b5d86cb070130f80bb40 to your computer and use it in GitHub Desktop.
Extension to fix orientation of an UIImage (Sets orientation to portrait)
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
extension UIImage { | |
func fixedOrientation() -> UIImage { | |
if imageOrientation == UIImageOrientation.Up { | |
return self | |
} | |
var transform: CGAffineTransform = CGAffineTransformIdentity | |
switch imageOrientation { | |
case UIImageOrientation.Down, UIImageOrientation.DownMirrored: | |
transform = CGAffineTransformTranslate(transform, size.width, size.height) | |
transform = CGAffineTransformRotate(transform, CGFloat(M_PI)) | |
break | |
case UIImageOrientation.Left, UIImageOrientation.LeftMirrored: | |
transform = CGAffineTransformTranslate(transform, size.width, 0) | |
transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2)) | |
break | |
case UIImageOrientation.Right, UIImageOrientation.RightMirrored: | |
transform = CGAffineTransformTranslate(transform, 0, size.height) | |
transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2)) | |
break | |
case UIImageOrientation.Up, UIImageOrientation.UpMirrored: | |
break | |
} | |
switch imageOrientation { | |
case UIImageOrientation.UpMirrored, UIImageOrientation.DownMirrored: | |
CGAffineTransformTranslate(transform, size.width, 0) | |
CGAffineTransformScale(transform, -1, 1) | |
break | |
case UIImageOrientation.LeftMirrored, UIImageOrientation.RightMirrored: | |
CGAffineTransformTranslate(transform, size.height, 0) | |
CGAffineTransformScale(transform, -1, 1) | |
case UIImageOrientation.Up, UIImageOrientation.Down, UIImageOrientation.Left, UIImageOrientation.Right: | |
break | |
} | |
let ctx: CGContextRef = CGBitmapContextCreate(nil, Int(size.width), Int(size.height), CGImageGetBitsPerComponent(CGImage), 0, CGImageGetColorSpace(CGImage), CGImageAlphaInfo.PremultipliedLast.rawValue)! | |
CGContextConcatCTM(ctx, transform) | |
switch imageOrientation { | |
case UIImageOrientation.Left, UIImageOrientation.LeftMirrored, UIImageOrientation.Right, UIImageOrientation.RightMirrored: | |
CGContextDrawImage(ctx, CGRectMake(0, 0, size.height, size.width), CGImage) | |
break | |
default: | |
CGContextDrawImage(ctx, CGRectMake(0, 0, size.width, size.height), CGImage) | |
break | |
} | |
let cgImage: CGImageRef = CGBitmapContextCreateImage(ctx)! | |
return UIImage(CGImage: cgImage) | |
} | |
} |
I believe those transform around the origin (0, 0) and would thus flip/rotate your image to be outside the box. if you try it with an angle of around 45° you’ll see how it would break.
Thanks!
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
I believe those transform around the origin (0, 0) and would thus flip/rotate your image to be outside the box. if you try it with an angle of around 45° you’ll see how it would break.