我正在使用核心图像,并且将CIFilter棕褐色调应用于图像。我在viewDidLoad中运行了一次过滤器,然后立即调用另一个再次添加过滤器的函数。由于某些原因,当我尝试访问输出图像时,应用程序崩溃并说输出图像为nil。有人知道为什么会这样吗?
谢谢
import UIKit class ViewController: UIViewController { @IBOutlet weak var myimage: UIImageView! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. let image = CIImage(image: myimage.image) let filter = CIFilter(name: "CISepiaTone") filter.setDefaults() filter.setValue(image, forKey: kCIInputImageKey) myimage.image = UIImage(CIImage: filter.outputImage) self.reapplyFilter() } func reapplyFilter(){ let image = CIImage(image: myimage.image) let filter = CIFilter(name: "CISepiaTone") filter.setDefaults() filter.setVa lue(image, forKey: kCIInputImageKey) //ERROR HERE: fatal error: unexpectedly found nil while unwrapping an Optional value myimage.image = UIImage(CIImage: filter.outputImage) //ERROR } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }
您不能调用UIImage(CIImage:)该UIImage并将其用作UIImageView的图像。UIImageView需要一个由位图(CGImage)支持的UIImage。用CIImage实例化的UIImage没有位图;它没有实际图像,只是一组应用滤镜的说明。这就是为什么UIImageView的图像为nil的原因。
UIImage(CIImage:)