ios - 使用给定路径裁剪图像

Question

是否有基于给定路径（CGPath）剪辑图像块（UIImage）的标准方法？（路径是椭圆，星形，多边形......）我现在的问题与这个有关： AVCaptureStillImageOutput 区域选择 ，暂时没有答案，我仍然没有解决方案。

Answer 1

使用此代码

CGPathRef path = CGPathCreateWithEllipseInRect(CGRectMake(50.0,50.0,300.0,200.0), nil);

UIGraphicsBeginImageContext(self.view.bounds.size);
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor blackColor].CGColor);
CGContextAddPath(UIGraphicsGetCurrentContext(), path);
CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(), [UIColor redColor].CGColor);
CGContextDrawPath(UIGraphicsGetCurrentContext(), kCGPathFillStroke);
UIImage *maskImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIImage *originalImage = [UIImage imageNamed:@"image"];
UIGraphicsBeginImageContext(self.view.bounds.size);
CGContextClipToMask(UIGraphicsGetCurrentContext(), CGRectMake(0.0,0.0,300.0,200.0), maskImage.CGImage);
[captureImage drawAtPoint:CGPointZero];
UIImage *clippedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();