如何在iPhone上检测最大纹理分辨率？

import UIKit

class MaximumTextureSizeViewController: UIViewController {
    
    @IBOutlet weak var textureView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        checkMaximumTextureSize()
    }
    
    private func checkMaximumTextureSize() {
        let context = CIContext()
        let cgImage = context.createCGImage(CIImage(cvPixelBuffer: pixelBuffer), from: CIImage(cvPixelBuffer: pixelBuffer).extent)
        
        let maxSize = CGSize(width: 2048, height: 2048)
        let options = [CIDetectorImageOrientation: .up, CIDetectorSmallerSizeLimit: maxSize] as [String : Any]
        
        guard let detector = CIDetector(ofType: CIDetectorTypeFace, context: context, options: options) else {
            return
        }
        
        detector.features = [CIDetectorFeature(type: CIDetectorFeature.TypeFace, properties: [CIDetectorPropertyAccuracy: CIDetectorAccuracyHigh])] as NSArray
        
        let ciImage = CIImage(cgImage: cgImage)
        detector.detect(ciImage)
        
        let maxDimension = ciImage.extent.size.width
        print("Maximum texture size: \(maxDimension)")
    }
}