AI Vision 框架错误：M1 Mac 中的“无法创建 Espresso 上下文”

Question

I am making an app to classify food images. I trained a model using a dataset found from Kaggle. When press the classify button I am getting this error in console:

Error Domain=com.apple.vis Code=9 "Could not create Espresso context" UserInfo={NSLocalizedDescription=Could not create Espresso context}

So I was looking for solution by googling and found in apple developer forum that it is M1 Mac specific issue. What should I do now?

Classify class:

import Foundation
import CoreML
import Vision
import UIKit

class VisionClasifier{
    private let model : VNCoreMLModel
    private var completion: (String) -> Void = { _ in }
    
    private lazy var request:[VNCoreMLRequest] = {
        let request = VNCoreMLRequest(model: model){ request, error in
            
            guard let results = request.results as? [VNClassificationObservation] else{
                return
            }
            
            if !results.isEmpty{
                if let result = results.first{
                    self.completion(result.identifier)
                }
            }
        }
        
        request.imageCropAndScaleOption = .centerCrop
        return [request]
    }()
    
    init?(mlModel:MLModel?){
        if let m = mlModel{
            if let model = try? VNCoreMLModel(for: m){
                self.model = model
            }else{
                return nil
            }
        }else{
            return nil
        }
        
    }
    
    func classify(_ image:UIImage, completion:@escaping (String)->Void){
        self.completion = completion
        DispatchQueue.global().async {
            guard let image = image.cgImage else{
                return
            }
            
            let handler = VNImageRequestHandler(cgImage: image, options: [:])
            
            do{
                try handler.perform(self.request)
            }catch{
                print(error) // -> here is the error
            }
        }
    }
}

Is this an M1 Mac specific error?

Answer 1

Yes, it can be a M1 specific error.

after line:

request.imageCropAndScaleOption = .centerCrop

add

request.usesCPUOnly = true