UIImage from NSData with wrong orientation

Question

My app pick a photo from camera roll and store it as NSData. When I need to show the image in my app I create the UIImage from NSData.

If the original photo is an image I save from web, google image or so, the UIImage has right orientation, if the original photo is a portrait photo I shoot with the iPhone, the UIImage is rotated 90 degrees left.

I cannot imagine how to know which photo needs to rotate and which are OK.

any help is appreciated.

the code I use to save image as NSData in a coredata entity:

 asset.requestContentEditingInputWithOptions(PHContentEditingInputRequestOptions()) { (input, info) in
      if let imgurl = input?.fullSizeImageURL {
           let img = UIImage(data: NSData(contentsOfURL: imgurl)!)
           self.gearImage = img
           self.photoImageView.contentMode = UIViewContentMode.ScaleAspectFill
           self.photoImageView.image = self.gearImage
       }
}

then I save the NSData in coredata:

if self.gearImage != nil {
    newItem.cgPhoto = UIImagePNGRepresentation(self.gearImage!)
}

When I have to show the image I fetch the coredata entity and:

let img = UIImage(data: self.imageData)

And here is the problem. If the phasset fullSizeImageOrientation is null or 1 the image is OK, else has wrong rotation.

Max

Answer 1

Probably this is due to the format in which you generate the data from picture. Try convert it from jpg format first because not all formats contain information about the rotation of the image. Try something like this:

var imageData: NSData?
if let _jpgData = UIImageJPEGRepresentation(image, 0) {
    imageData = _jpgData
} else if let _pngData = UIImagePNGRepresentation(image) {
    imageData = _pngData
}