image orientation correction

normalize_image_orientation.m

// simple but not performance wise
- (UIImage *)normalizeImageOrientation:(NSString *)path {
   UIImage *image = [UIImage imageWithContentsOfFile:path];

  if (image.imageOrientation != UIImageOrientationUp) {
    CGSize size = image.size;
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0, 0, size.width, size.height)];
    image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
  }
  return image;
}