Brtdku

This is the complete code for rotation of image to any degree just add it to appropriate file ie in .m as below where you want to use the image processing

for .m

@interface UIImage (RotationMethods)

- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;

@end



@implementation UIImage (RotationMethods)



static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};



- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees 

{   

    // calculate the size of the rotated view's containing box for our drawing space

    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];

    CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));

    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;



    // Create the bitmap context

    UIGraphicsBeginImageContext(rotatedSize);

    CGContextRef bitmap = UIGraphicsGetCurrentContext();



    // Move the origin to the middle of the image so we will rotate and scale around the center.

    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);



    //   // Rotate the image context

    CGContextRotateCTM(bitmap, DegreesToRadians(degrees));



    // Now, draw the rotated/scaled image into the context

    CGContextScaleCTM(bitmap, 1.0, -1.0);

    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);



    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;



}



@end

This is the code snippet form apple's SquareCam example.

To call the above method just use the below code

UIImage *rotatedSquareImage = [square imageRotatedByDegrees:rotationDegrees];

Here the square is one UIImage and rotationDegrees is one flote ivar to rotate the image that degrees

Swift 3 and Swift 4 use .pi instead

eg:

//rotate 90 degrees

myImageView.transform = CGAffineTransform(rotationAngle: .pi / 2)



//rotate 180 degrees

myImageView.transform = CGAffineTransform(rotationAngle: .pi)



//rotate 270 degrees

myImageView.transform = CGAffineTransform(rotationAngle: .pi * 1.5)

- (UIImage *)rotateImage:(UIImage*)image byDegree:(CGFloat)degrees 

{   

    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,image.size.width, image.size.height)];

    CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));

    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;

    [rotatedViewBox release];



    UIGraphicsBeginImageContext(rotatedSize);

    CGContextRef bitmap = UIGraphicsGetCurrentContext();





    CGContextTranslateCTM(bitmap, rotatedSize.width, rotatedSize.height);



    CGContextRotateCTM(bitmap, DegreesToRadians(degrees));





    CGContextScaleCTM(bitmap, 1.0, -1.0);

    CGContextDrawImage(bitmap, CGRectMake(-image.size.width, -image.size.height, image.size.width, image.size.height), [image CGImage]);



    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;



}

Simply add this code to the image.

Image.transform=CGAffineTransformMakeRotation(M_PI / 2);

I got an error trying this in XCode 6.3 Swift 1.2

self.imageview.transform = CGAffineTransformMakeRotation(M_PI_2);

You should try this to force type cast fix:

self.imageview.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2));

Swift 3 version:

imageView.transform = CGAffineTransform(rotationAngle: CGFloat(M_PI_2))

Swift 4 | Xcode 9 syntax (please note that this code rotates a UIImageView 90 degrees clockwise, not a UIImage):

myImageView.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi / 2))

Swift 4+.

arrowImageView.transform = CGAffineTransform(rotationAngle: .pi/2)

Note: angle is in radian

.pi = 180 degree

.pi/2 = 90 degree

If you want to add with animation

  @IBAction func applyTransForm(sender: UIButton) {

        sender.isSelected = !sender.isSelected

        UIView.animate(withDuration: 1, animations: {

        if sender.isSelected {

            self.arrowImageView.transform = CGAffineTransform(rotationAngle: .pi)

        } else {

            self.arrowImageView.transform = CGAffineTransform(rotationAngle: 0)



        }

        })

    }

Output:

Here is the Swift 2.2 version of The iOSDev answer (in UIImage extension):

func degreesToRadians(degrees: CGFloat) -> CGFloat {

    return degrees * CGFloat(M_PI) / 180

}



func imageRotatedByDegrees(degrees: CGFloat) -> UIImage {

    // calculate the size of the rotated view's containing box for our drawing space

    let rotatedViewBox = UIView(frame: CGRectMake(0,0,self.size.width, self.size.height))

    let t = CGAffineTransformMakeRotation(self.degreesToRadians(degrees))

    rotatedViewBox.transform = t

    let rotatedSize = rotatedViewBox.frame.size



    // Create the bitmap context

    UIGraphicsBeginImageContext(rotatedSize)

    let bitmap = UIGraphicsGetCurrentContext()



    // Move the origin to the middle of the image so we will rotate and scale around the center.

    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);



    // Now, draw the rotated/scaled image into the context

    CGContextScaleCTM(bitmap, 1.0, -1.0);

    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), self.CGImage);



    let newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;



}

It´s best only use the bitmap. In my case use a UIImage that is in reference.image and I converted image at base64String. Without CGAffineTransformMakeRotation and without rotatedViewBox.transform

var rotatedSize = reference.image.size;

                //Create bitmap context

                UIGraphicsBeginImageContext(rotatedSize);

                var bitmap = UIGraphicsGetCurrentContext();

                //move origin to the middle of the image for rotation

                CGContextTranslateCTM(bitmap, rotatedSize.width / 2, rotatedSize.height / 2);

                //rotate image context

                CGContextRotateCTM(bitmap, 1.5708);

                CGContextDrawImage(bitmap, CGRectMake(-reference.image.size.width / 2, -reference.image.size.height / 2, reference.image.size.width, reference.image.size.height), reference.image.CGImage);

                var rotatedImage = UIGraphicsGetImageFromCurrentImageContext();

                var base64Image = UIImageJPEGRepresentation(rotatedImage, compression).base64EncodedStringWithOptions(0);

                UIGraphicsEndImageContext();

                return base64Image;