image cropping and zooming in circular format in iOS?

Happy new year. Here i m trying to zoom cropped area and trying to do dropped area in circular format, but i didn't get proper solution for this. so please help me anybody know this?

CALayer* layer = self.blurredImageView.layer;
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextAddRect(c, self.cropArea);
CGContextAddRect(c, rect);
CGContextEOClip(c);
CGContextSetFillColorWithColor(c, [UIColor blackColor].CGColor);
CGContextFillRect(c, rect);
UIImage* maskim = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();