iOS - UIImageView - how to handle UIImage image orientation

IosUiimageviewUiimageOrientation

Ios Problem Overview


Is it possible to setup UIImageView to handle image orientation? When I set the UIImageView to image with orientation RIGHT (it is photo from camera roll), the image is rotated to right, but I want to show it in proper orientation, as it was taken.

I know I can rotate image data but it is possible to do it more elegant?

Ios Solutions


Solution 1 - Ios

If I understand, what you want to do is disregard the orientation of the UIImage? If so then you could do this:

UIImage *originalImage = [... whatever ...];

UIImage *imageToDisplay =
     [UIImage imageWithCGImage:[originalImage CGImage]
              scale:[originalImage scale]
              orientation: UIImageOrientationUp];

So you're creating a new UIImage with the same pixel data as the original (referenced via its CGImage property) but you're specifying an orientation that doesn't rotate the data.

Solution 2 - Ios

You can completely avoid manually doing the transforms and scaling yourself, as suggested by an0 in this answer here:

- (UIImage *)normalizedImage {
    if (self.imageOrientation == UIImageOrientationUp) return self; 

    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    [self drawInRect:(CGRect){0, 0, self.size}];
    UIImage *normalizedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return normalizedImage;
}

The documentation for the UIImage methods size and drawInRect explicitly states that they take into account orientation.

Solution 3 - Ios

Swift 3.1

func fixImageOrientation(_ image: UIImage)->UIImage {
    UIGraphicsBeginImageContext(image.size)
    image.draw(at: .zero)
    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return newImage ?? image
}

Solution 4 - Ios

This method first checks the current orientation of UIImage and then it changes the orientation in a clockwise way and return UIImage.You can show this image as > self.imageView.image = rotateImage(currentUIImage)

   func rotateImage(image:UIImage)->UIImage
    {
        var rotatedImage = UIImage();
        switch image.imageOrientation
        {
            case UIImageOrientation.Right:
            rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Down);
            
           case UIImageOrientation.Down:
            rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Left);
            
            case UIImageOrientation.Left:
            rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Up);
    
             default:
            rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Right);
        }
        return rotatedImage;
    }
Swift 4 version
extension UIImage {

func rotate() -> UIImage {
    var rotatedImage = UIImage()
    guard let cgImage = cgImage else {
        print("could not rotate image")
        return self
    }
    switch imageOrientation {
    case .right:
        rotatedImage = UIImage(cgImage: cgImage, scale: scale, orientation: .down)
    case .down:
        rotatedImage = UIImage(cgImage: cgImage, scale: scale, orientation: .left)
    case .left:
        rotatedImage = UIImage(cgImage: cgImage, scale: scale, orientation: .up)
    default:
        rotatedImage = UIImage(cgImage: cgImage, scale: scale, orientation: .right)
    }
    
    return rotatedImage
}
}

Solution 5 - Ios

I converted the code in Anomie's answer here (copy-pasted above by suvish valsan) into Swift:

func fixOrientation() -> UIImage {
    if self.imageOrientation == UIImageOrientation.Up {
        return self
    }
    
    var transform = CGAffineTransformIdentity
    
    switch self.imageOrientation {
    case .Down, .DownMirrored:
        transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI));
        
    case .Left, .LeftMirrored:
        transform = CGAffineTransformTranslate(transform, self.size.width, 0);
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2));
        
    case .Right, .RightMirrored:
        transform = CGAffineTransformTranslate(transform, 0, self.size.height);
        transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2));
    
    case .Up, .UpMirrored:
        break
    }
    
    switch self.imageOrientation {
        
    case .UpMirrored, .DownMirrored:
        transform = CGAffineTransformTranslate(transform, self.size.width, 0)
        transform = CGAffineTransformScale(transform, -1, 1)
        
    case .LeftMirrored, .RightMirrored:
        transform = CGAffineTransformTranslate(transform, self.size.height, 0)
        transform = CGAffineTransformScale(transform, -1, 1);
    
    default:
        break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    let ctx = CGBitmapContextCreate(
        nil,
        Int(self.size.width),
        Int(self.size.height),
        CGImageGetBitsPerComponent(self.CGImage),
        0,
        CGImageGetColorSpace(self.CGImage),
        UInt32(CGImageGetBitmapInfo(self.CGImage).rawValue)
    )
    
    CGContextConcatCTM(ctx, transform);
 
    switch self.imageOrientation {
    case .Left, .LeftMirrored, .Right, .RightMirrored:
        // Grr...
        CGContextDrawImage(ctx, CGRectMake(0, 0, self.size.height,self.size.width), self.CGImage);
        
    default:
        CGContextDrawImage(ctx, CGRectMake(0, 0, self.size.width,self.size.height), self.CGImage);
        break;
    }
    
    // And now we just create a new UIImage from the drawing context
    let cgimg = CGBitmapContextCreateImage(ctx)
    
    let img = UIImage(CGImage: cgimg!)
    
    return img;
}

(I replaced all occurencies of the parameter image with self, because my code is an extension on UIImage).


EDIT: Swift 3 version.

The method returns an optional, because many of the intermediate calls can fail and I don't like to use !.

func fixOrientation() -> UIImage? {
    
    guard let cgImage = self.cgImage else {
        return nil
    }
    
    if self.imageOrientation == UIImageOrientation.up {
        return self
    }
    
    let width  = self.size.width
    let height = self.size.height
    
    var transform = CGAffineTransform.identity
    
    switch self.imageOrientation {
    case .down, .downMirrored:
        transform = transform.translatedBy(x: width, y: height)
        transform = transform.rotated(by: CGFloat.pi)
        
    case .left, .leftMirrored:
        transform = transform.translatedBy(x: width, y: 0)
        transform = transform.rotated(by: 0.5*CGFloat.pi)
        
    case .right, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: height)
        transform = transform.rotated(by: -0.5*CGFloat.pi)
        
    case .up, .upMirrored:
        break
    }
    
    switch self.imageOrientation {
    case .upMirrored, .downMirrored:
        transform = transform.translatedBy(x: width, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
        
    case .leftMirrored, .rightMirrored:
        transform = transform.translatedBy(x: height, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
        
    default:
        break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    guard let colorSpace = cgImage.colorSpace else {
        return nil
    }

    guard let context = CGContext(
        data: nil,
        width: Int(width),
        height: Int(height),
        bitsPerComponent: cgImage.bitsPerComponent,
        bytesPerRow: 0,
        space: colorSpace,
        bitmapInfo: UInt32(cgImage.bitmapInfo.rawValue)
        ) else {
            return nil
    }
    
    context.concatenate(transform);
    
    switch self.imageOrientation {
        
    case .left, .leftMirrored, .right, .rightMirrored:
        // Grr...
        context.draw(cgImage, in: CGRect(x: 0, y: 0, width: height, height: width))
    
    default:
        context.draw(cgImage, in: CGRect(x: 0, y: 0, width: width, height: height))
    }
    
    // And now we just create a new UIImage from the drawing context
    guard let newCGImg = context.makeImage() else {
        return nil
    }
    
    let img = UIImage(cgImage: newCGImg)
    
    return img;
}

(Note: Swift 3 version odes compile under Xcode 8.1, but haven't tested it actually works. There might be a typo somewhere, mixed up width/height, etc. Feel free to point/fix any errors).

Solution 6 - Ios

UIImage extension in Swift. You don't need to do all that flipping at all, really. Objective-C original is here, but I've added the bit that respects the alpha of the original image (crudely, but it works to differentiate opaque images from transparent images).

// from https://github.com/mbcharbonneau/UIImage-Categories/blob/master/UIImage%2BAlpha.m
// Returns true if the image has an alpha layer
    private func hasAlpha() -> Bool {
        guard let cg = self.cgImage else { return false }
        let alpha = cg.alphaInfo
        let retVal = (alpha == .first || alpha == .last || alpha == .premultipliedFirst || alpha == .premultipliedLast)
        return retVal
    }
    
    func normalizedImage() -> UIImage? {
        if self.imageOrientation == .up {
            return self
        }
        UIGraphicsBeginImageContextWithOptions(self.size, !self.hasAlpha(), self.scale)
        var rect = CGRect.zero
        rect.size = self.size
        self.draw(in: rect)
        let retVal = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return retVal
    }

Solution 7 - Ios

here is a workable sample cod, considering the image orientation:

#define rad(angle) ((angle) / 180.0 * M_PI)
- (CGAffineTransform)orientationTransformedRectOfImage:(UIImage *)img
{
    CGAffineTransform rectTransform;
    switch (img.imageOrientation)
    {
        case UIImageOrientationLeft:
            rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(90)), 0, -img.size.height);
            break;
        case UIImageOrientationRight:
            rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(-90)), -img.size.width, 0);
            break;
        case UIImageOrientationDown:
            rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(-180)), -img.size.width, -img.size.height);
            break;
        default:
            rectTransform = CGAffineTransformIdentity;
    };
    
    return CGAffineTransformScale(rectTransform, img.scale, img.scale);
}


- (UIImage *)croppedImage:(UIImage*)orignialImage InRect:(CGRect)visibleRect{
    //transform visible rect to image orientation
    CGAffineTransform rectTransform = [self orientationTransformedRectOfImage:orignialImage];
    visibleRect = CGRectApplyAffineTransform(visibleRect, rectTransform);
    
    //crop image
    CGImageRef imageRef = CGImageCreateWithImageInRect([orignialImage CGImage], visibleRect);
    UIImage *result = [UIImage imageWithCGImage:imageRef scale:orignialImage.scale orientation:orignialImage.imageOrientation];
    CGImageRelease(imageRef);
    return result;
}

Solution 8 - Ios

I converted the code from @Nicolas Miari answer to Swift 3 in case anybody needs it

func fixOrientation() -> UIImage
{
    
    if self.imageOrientation == UIImageOrientation.up {
        return self
    }
    
    var transform = CGAffineTransform.identity
    
    switch self.imageOrientation {
    case .down, .downMirrored:
        transform = transform.translatedBy(x: self.size.width, y: self.size.height)
        transform = transform.rotated(by: CGFloat(M_PI));
        
    case .left, .leftMirrored:
        transform = transform.translatedBy(x: self.size.width, y: 0);
        transform = transform.rotated(by: CGFloat(M_PI_2));
        
    case .right, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: self.size.height);
        transform = transform.rotated(by: CGFloat(-M_PI_2));
        
    case .up, .upMirrored:
        break
    }
    
    
    switch self.imageOrientation {
        
    case .upMirrored, .downMirrored:
        transform = transform.translatedBy(x: self.size.width, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
        
    case .leftMirrored, .rightMirrored:
        transform = transform.translatedBy(x: self.size.height, y: 0)
        transform = transform.scaledBy(x: -1, y: 1);
        
    default:
        break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    let ctx = CGContext(
        data: nil,
        width: Int(self.size.width),
        height: Int(self.size.height),
        bitsPerComponent: self.cgImage!.bitsPerComponent,
        bytesPerRow: 0,
        space: self.cgImage!.colorSpace!,
        bitmapInfo: UInt32(self.cgImage!.bitmapInfo.rawValue)
    )

    
    
    ctx!.concatenate(transform);
    
    switch self.imageOrientation {
        
    case .left, .leftMirrored, .right, .rightMirrored:
        // Grr...
        ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.height ,height:self.size.width))
        
    default:
        ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.width ,height:self.size.height))
        break;
    }
    
    // And now we just create a new UIImage from the drawing context
    let cgimg = ctx!.makeImage()
    
    let img = UIImage(cgImage: cgimg!)
    
    return img;
    
}

Solution 9 - Ios

If you need to rotate and fix the image orientation below extension would be useful.

extension UIImage {
    
    public func imageRotatedByDegrees(degrees: CGFloat) -> UIImage {
        //Calculate the size of the rotated view's containing box for our drawing space
        let rotatedViewBox: UIView = UIView(frame: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
        let t: CGAffineTransform = CGAffineTransform(rotationAngle: degrees * CGFloat.pi / 180)
        rotatedViewBox.transform = t
        let rotatedSize: CGSize = rotatedViewBox.frame.size
        //Create the bitmap context
        UIGraphicsBeginImageContext(rotatedSize)
        let bitmap: CGContext = 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, y: rotatedSize.height / 2)
        //Rotate the image context
        bitmap.rotate(by: (degrees * CGFloat.pi / 180))
        //Now, draw the rotated/scaled image into the context
        bitmap.scaleBy(x: 1.0, y: -1.0)
        bitmap.draw(self.cgImage!, in: CGRect(x: -self.size.width / 2, y: -self.size.height / 2, width: self.size.width, height: self.size.height))
        let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return newImage
    }
    
    
    public func fixedOrientation() -> UIImage {
        if imageOrientation == UIImageOrientation.up {
            return self
        }
        
        var transform: CGAffineTransform = CGAffineTransform.identity
        
        switch imageOrientation {
        case UIImageOrientation.down, UIImageOrientation.downMirrored:
            transform = transform.translatedBy(x: size.width, y: size.height)
            transform = transform.rotated(by: CGFloat.pi)
            break
        case UIImageOrientation.left, UIImageOrientation.leftMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.rotated(by: CGFloat.pi/2)
            break
        case UIImageOrientation.right, UIImageOrientation.rightMirrored:
            transform = transform.translatedBy(x: 0, y: size.height)
            transform = transform.rotated(by: -CGFloat.pi/2)
            break
        case UIImageOrientation.up, UIImageOrientation.upMirrored:
            break
        }
        
        switch imageOrientation {
        case UIImageOrientation.upMirrored, UIImageOrientation.downMirrored:
            transform.translatedBy(x: size.width, y: 0)
            transform.scaledBy(x: -1, y: 1)
            break
        case UIImageOrientation.leftMirrored, UIImageOrientation.rightMirrored:
            transform.translatedBy(x: size.height, y: 0)
            transform.scaledBy(x: -1, y: 1)
        case UIImageOrientation.up, UIImageOrientation.down, UIImageOrientation.left, UIImageOrientation.right:
            break
        }
        
        let ctx: CGContext = CGContext(data: nil,
                                       width: Int(size.width),
                                       height: Int(size.height),
                                       bitsPerComponent: self.cgImage!.bitsPerComponent,
                                       bytesPerRow: 0,
                                       space: self.cgImage!.colorSpace!,
                                       bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
        
        ctx.concatenate(transform)
        
        switch imageOrientation {
        case UIImageOrientation.left, UIImageOrientation.leftMirrored, UIImageOrientation.right, UIImageOrientation.rightMirrored:
            ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
        default:
            ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
            break
        }
        
        let cgImage: CGImage = ctx.makeImage()!
        
        return UIImage(cgImage: cgImage)
    }
}

Solution 10 - Ios

Thanks to Waseem05 for his Swift 3 translation but his method only worked for me when I wrapped it inside an extension to UIImage and placed it outside/below the parent class like so:

extension UIImage {

        func fixOrientation() -> UIImage
        {
    
            if self.imageOrientation == UIImageOrientation.up {
            return self
        }
    
        var transform = CGAffineTransform.identity
    
        switch self.imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: self.size.width, y: self.size.height)
            transform = transform.rotated(by: CGFloat(M_PI));
        
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: self.size.width, y: 0);
            transform = transform.rotated(by: CGFloat(M_PI_2));
        
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: self.size.height);
            transform = transform.rotated(by: CGFloat(-M_PI_2));
        
        case .up, .upMirrored:
            break
        }
    
    
        switch self.imageOrientation {
        
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: self.size.height, y: 0)
            transform = transform.scaledBy(x: -1, y: 1);
        
        default:
            break;
        }
    
        // Now we draw the underlying CGImage into a new context, applying the transform
        // calculated above.
        let ctx = CGContext(
            data: nil,
            width: Int(self.size.width),
            height: Int(self.size.height),
            bitsPerComponent: self.cgImage!.bitsPerComponent,
            bytesPerRow: 0,
            space: self.cgImage!.colorSpace!,
            bitmapInfo: UInt32(self.cgImage!.bitmapInfo.rawValue)
        )
    
    
    
        ctx!.concatenate(transform);
    
        switch self.imageOrientation {
        
        case .left, .leftMirrored, .right, .rightMirrored:
            // Grr...
            ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.height ,height:self.size.width))
        
        default:
            ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.width ,height:self.size.height))
            break;
        }
    
        // And now we just create a new UIImage from the drawing context
        let cgimg = ctx!.makeImage()
    
        let img = UIImage(cgImage: cgimg!)
    
        return img;
    
    }
}

Then called it with:

let correctedImage:UIImage = wonkyImage.fixOrientation()

And all was then well! Apple should make it easier to discard orientation when we don't need front/back camera and up/down/left/right device orientation metadata.

Solution 11 - Ios

extension UIImage {
    func fixImageOrientation() -> UIImage {
        UIGraphicsBeginImageContext(self.size)
        self.draw(at: .zero)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage ?? self
    }
}
  1. Create extension like top example.

  2. Call it: imageView.image?.fixImageOrientation() or UIImage(named: "someImage").fixImageOrientation()

  3. Good luck all!

Solution 12 - Ios

Swift 3.0 version of Tommy's answer

let imageToDisplay = UIImage.init(cgImage: originalImage.cgImage!, scale: originalImage.scale, orientation: UIImageOrientation.up)

Solution 13 - Ios

Inspired from @Aqua Answer.....

in Objective C

- (UIImage *)fixImageOrientation:(UIImage *)img {

   UIGraphicsBeginImageContext(img.size);
   [img drawAtPoint:CGPointZero];

   UIImage *newImg = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();

   if (newImg) {
       return newImg;
   }

   return img;
}

Solution 14 - Ios

I tried the checkmarked solution and it doesn't work for me. But the below solution works for fixing orientation from camera before converting to png.

Swift 5:

let imageToDisplay = originalImage.resize(new: originalImage.resize)

Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionMartin PilchView Question on Stackoverflow
Solution 1 - IosTommyView Answer on Stackoverflow
Solution 2 - Iosuser2067021View Answer on Stackoverflow
Solution 3 - IosAquaView Answer on Stackoverflow
Solution 4 - Iosvarender singhView Answer on Stackoverflow
Solution 5 - IosNicolas MiariView Answer on Stackoverflow
Solution 6 - IosDan RosenstarkView Answer on Stackoverflow
Solution 7 - IoslbsweekView Answer on Stackoverflow
Solution 8 - IosWaseem05View Answer on Stackoverflow
Solution 9 - IosDhaval H. NenaView Answer on Stackoverflow
Solution 10 - IoshawtakshunView Answer on Stackoverflow
Solution 11 - IosMihail SalariView Answer on Stackoverflow
Solution 12 - IosAbdurrahman Mubeen AliView Answer on Stackoverflow
Solution 13 - IosumakantaView Answer on Stackoverflow
Solution 14 - IosVictor KosseView Answer on Stackoverflow