image uploaded rotated other way - ios

Question

let image_data = UIImageJPEGRepresentation(self.imagetoadd.image!,0.0)
The image in ios, am using swift 3 to do this is being uploaded rotated.How can I solve such thing?

Answer 1

JPEG images usually contain an EXIF dictionary, here are stored a lot information about how the image was taken, image rotation is one of it.
UIImage instances keeps these information (if the original image has it) as well inside a specific property called imageOrientation.
As far as I remember this information is ripped of by using the method UIImageJPEGRepresentation.
To create a correct data instance with the above information you must use Core Graphics methods, or normalize the rotation before sending the image.
To normalize the image something like that should be enough:
CGImageRef cgRef = imageToSave.CGImage;
UIImage * fixImage = [[UIImage alloc] initWithCGImage:cgRef scale:imageToSave.scale orientation:UIImageOrientationUp];
To keep the rotation information:
CFURLRef url = (__bridge_retained CFURLRef)[NSURL fileURLWithPath:path];//Save data path
NSDictionary * metadataDictionary = [self imageMetadataForPath:pathToOriginalImage];
CFMutableDictionaryRef metadataImage = (__bridge_retained CFMutableDictionaryRef) metadata;
CGImageDestinationRef destination = CGImageDestinationCreateWithURL(url, kUTTypeJPEG, 1, NULL);
CGImageDestinationAddImage(destination, image, metadataImage);
if (!CGImageDestinationFinalize(destination)) {
DLog(#"Failed to write image to %#", path);
}
Where the -imageMetadataForPath:
- (NSDictionary*) imageMetadataForPath:(NSString*) imagePath{
NSURL *imageURL = [NSURL fileURLWithPath:imagePath];
CGImageSourceRef mySourceRef = CGImageSourceCreateWithURL((__bridge CFURLRef)imageURL, NULL);
NSDictionary * dict = (NSDictionary *) CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(mySourceRef,0,NULL));
CFRelease(mySourceRef);
return dict;
}
This is a copy and paste from a project of mine, you probably need to do a huge refactoring, also because it is using manual memory management in core foundation and you are using SWIFT. Of course by using this last set of instructions, the backend code must be prepared to deal with image orientation too.
If you want to know more about rotation, here is a link.