UIImage category to normalize image orientation by rotating an image so that it's orientation is UIImageOrientationUp. Based on http://stackoverflow.com/questions/5427656/ios-uiimagepickercontroller-result-image-orientation-after-upload/5427890#10611036

gistfile1.m

@interface UIImage (Orientation)

- (UIImage*)imageByNormalizingOrientation;

@end


@implementation UIImage (Orientation)

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

@end

Updated to Swift3
https://gist.github.com/NikhilManapure/42bf67cdc568058938c7ac38d84c4144