UIImageの回転

UIImageの回転

_imageOriginal = [UIImage imageNamed:@"購入記録no1.png"];

UIGraphicsBeginImageContextWithOptions(CGSizeMake(_imageOriginal.size.height, _imageOriginal.size.width), YES, _imageOriginal.scale);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, _imageOriginal.size.height, _imageOriginal.size.width);
CGContextScaleCTM(context, 1, -1);
CGContextRotateCTM(context, M_PI_2);

CGImageRef      imgRef = [_imageOriginal CGImage];
CGContextDrawImage(context, CGRectMake(0, 0, _imageOriginal.size.width, _imageOriginal.size.height), imgRef);
_imageRotation = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();