Core Image：合并两个 CIImage Swift

Question

所以我有 2 个 CIImage 想要合并在一起，所以每个的 alpha 为 0.5。我该怎么做？

我厌倦了以下代码，但生成的图像大小不正确，并且两个图像未正确结合...请帮助！

if let image = CIImage(contentsOf: imageURL) {
    let randomFilter = CIFilter(name: "CIRandomGenerator")
    let noiseImage = randomFilter!.outputImage!.cropped(to: (CGRect(x: CGFloat(Int.random(in: 1..<1000)), y: CGFloat(Int.random(in: 1..<1000)), width: image.extent.width, height: image.extent.height)))
    let compoimg = noiseImage.composited(over: image) //Misaligned image

} 

Answer 1

问题在于随机噪声生成器，因为随机噪声是从无限噪声映射中裁剪出来的......正确的代码可以补偿这种转换：

if let image = CIImage(contentsOf: imageURL) {
    let randomFilter = CIFilter(name: "CIRandomGenerator")
    let randX = CGFloat(Int.random(in: 0..<1000))
    let randY = CGFloat(Int.random(in: 0..<1000))
    let noiseImage = randomFilter!.outputImage!.cropped(to: (CGRect(x: randX, y: randY, width: image.extent.width, height: image.extent.height)))
    let tt = noiseImage.transformed(by: CGAffineTransform.init(translationX: -randX, y: -randY))
    let compoimg = tt.composited(over: image) //Correctly allied image
}