Ios 如何使用Swift 4在ARKit中实现实时摄像机过滤器？

我想在我的项目中集成iPhone摄像头过滤器，我的项目基于ARKit，我想应用苹果在摄像头应用程序中提供的各种过滤器，特别是生动、生动、温暖和生动、凉爽

我已经尝试了我在下面提到的各种可能性

func session(_ session: ARSession, didUpdate frame: ARFrame) {
        guard let currentBackgroundFrameImage = sceneView.session.currentFrame?.capturedImage,
        let pixelBufferAddressOfPlane = CVPixelBufferGetBaseAddressOfPlane(currentBackgroundFrameImage, 1) else { return }

       let x: size_t = CVPixelBufferGetWidthOfPlane(currentBackgroundFrameImage, 1)
       let y: size_t = CVPixelBufferGetHeightOfPlane(currentBackgroundFrameImage, 1)
       memset(pixelBufferAddressOfPlane, 128, Int(x * y) * 2) }

我得到了黑白相机过滤器使用上述代码

func session(_ session: ARSession, didUpdate frame: ARFrame) {
        let bg = session.currentFrame?.capturedImage
        if (bg != nil) {
            let image = CIImage(cvPixelBuffer: bg!)
            let filter:CIFilter = CIFilter(name: "CIPixellate")!
            filter.setDefaults()
            filter.setValue(image, forKey: kCIInputImageKey)
            //let filteredImageData = filter.value(forKey: kCIOutputImageKey) as! CIImage

            let context = CIContext()
            //if let result = filter.outputImage,
            if let result = filter.value(forKey: kCIOutputImageKey) ,
                let cgImage = context.createCGImage(result as! CIImage, from: (result as! CIImage).extent) {
                let imageForUser = UIImage(cgImage: cgImage)
                sceneView.scene.background.contents = imageForUser
                sceneView.scene.background.contentsTransform = SCNMatrix4MakeRotation(.pi / 2, 0, 0, 1)
            }
        }
}

使用上面的代码，相机被卡住，渲染速度非常慢，有时应用程序会因为内存问题而崩溃。（在iPhone XR中测试）

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请帮助我了解实时摄像机过滤器功能。如果你能为我提供ARKit相机过滤器的代码，那就太好了。多谢各位

首先，不要在每一帧创建一个新的

CIContext

。这是一件非常昂贵的物品。尝试在初始化期间创建它，并在每一帧重复使用它。

func session(_ session: ARSession, didUpdate frame: ARFrame) {

   let image = CIImage(cvPixelBuffer: frame.capturedImage)
   let filter = CIFilter(name: "CIPixellate")!
   filter.setValue(image, forKey: kCIInputImageKey)
   let result = filter.outputImage!
   sceneView.scene.background.contents = context.createCGImage(result, from: image.extent)
   sceneView.scene.background.contentsTransform = SCNMatrix4MakeRotation(.pi / 2, 0, 0, 1) // fixes orientation

}