在CameraView中用Swift制作模糊的特定区域？

import AVFoundation
import CoreImage

class CameraViewController: UIViewController {
    var captureSession: AVCaptureSession?
    var videoPreviewLayer: AVCaptureVideoPreviewLayer?
    var blurFilter: CIFilter?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建相机预览视图
        captureSession = AVCaptureSession()
        guard let captureDevice = AVCaptureDevice.default(for: .video),
              let input = try? AVCaptureDeviceInput(device: captureDevice) else {
            return
        }
        captureSession?.addInput(input)
        
        videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
        videoPreviewLayer?.videoGravity = .resizeAspectFill
        videoPreviewLayer?.frame = view.layer.bounds
        view.layer.addSublayer(videoPreviewLayer!)
        
        // 创建模糊滤镜
        blurFilter = CIFilter(name: "CIGaussianBlur")
        
        // 创建特定区域
        let blurRect = CGRect(x: 100, y: 100, width: 200, height: 200)
        let blurLayer = CALayer()
        blurLayer.frame = blurRect
        view.layer.addSublayer(blurLayer)
        
        // 开始相机会话
        captureSession?.startRunning()
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        videoPreviewLayer?.frame = view.layer.bounds
    }
    
    func applyBlurToRect(rect: CGRect) {
        // 获取相机图像
        guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer),
              let sourceImage = CIImage(cvPixelBuffer: imageBuffer) else {
            return
        }
        
        // 将滤镜应用到图像上
        blurFilter?.setValue(sourceImage, forKey: kCIInputImageKey)
        blurFilter?.setValue(10, forKey: kCIInputRadiusKey)
        guard let outputImage = blurFilter?.outputImage else {
            return
        }
        
        // 将处理后的图像显示在特定区域上
        let context = CIContext()
        let cgImage = context.createCGImage(outputImage, from: outputImage.extent)
        blurLayer.contents = cgImage
    }
    
    // 在相机捕获到新的帧时调用
    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        // 应用模糊效果到特定区域
        applyBlurToRect(rect: blurRect)
    }
}