How to rotate an image 90 degrees on iOS?
self.imageview.transform = CGAffineTransformMakeRotation(M_PI_2);
Swift 4+:
self.imageview.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi/2))
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