Why are the corners of my UIImage being cut when I rotate it?

Question

hi all i rotate my UIImage for crop. when i am rotate my image it just cuts from corners here my code.

-(UIImage*)imageLeftRotation:(UIImage*) newImage size:(CGSize) imgSize angle:(int) rotateAngle{

    UIImage *image = newImage;
    CGImageRef imgRef = image.CGImage;

    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGAffineTransform transform = CGAffineTransformIdentity;
    CGRect bounds = CGRectMake(0, 0, width+angle, height+angle);
    transform = CGAffineTransformRotate(transform, degreesToRadians(angle));
    UIGraphicsBeginImageContext(bounds.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextConcatCTM(context, transform);

    CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(angle,0,width,height), imgRef);
    UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    mainImages =[imageCopy retain];
}

how does i can resolve this and where i am wrong.

Deepika