夹紧CIImage返回奇怪的大小

Question

我试图裁剪一幅图像，然后用夹子从边缘扩展颜色，但是在那之后，我会返回一个奇怪的图像大小：

let image = UIImage(named: "frame_1")
var ciimage = CIImage(image: image!)

print("\(ciimage!.extent.width) x \(ciimage!.extent.height)")
// at this point it returns "480.0 x 360.0" that is ok

ciimage = ciimage!.clamping(to: CGRect(x: 50, y: 50, width: 480.0, height: 360.0))

print("\(ciimage!.extent.width) x \(ciimage!.extent.height)")
//now it returns two strange values: "1.79769313486232e+308 x 1.79769313486232e+308"

夹紧后不应该还480.0和360.0吗？我做错什么了？

Answer 1

好的，我解决了这个问题，夹紧后裁剪它：

ciimage = ciimage!.clamping(to: CGRect(x: 50, y: 50, width: 480, height: 360))

ciimage = ciimage!.cropping(to: CGRect(x: 0, y: 0, width: 480, height: 360))

结果如我所料。