Swift – Remove image background with CoreML – Ios swift

I am using CoreML with the DeepLabV3 model to remove the background from an image: https://developer.apple.com/machine-learning/models/

This is working well for removing the background from photos where the subject it a person/dog/car, but for other cases, such as skylines and some objects on a table (please see example images), it is unable to detect the object from the background.

Should I be using a different method for this?

Thank you

var imageSegmentationModel = DeepLabV3()
var request :  VNCoreMLRequest?

func setUpModel() {
        if let visionModel = try? VNCoreMLModel(for: imageSegmentationModel.model) {
                request = VNCoreMLRequest(model: visionModel, completionHandler: visionRequestDidComplete)
                request?.imageCropAndScaleOption = .scaleFill
        }
        else {
                fatalError()
        }
}

func predict() {
        DispatchQueue.global(qos: .userInitiated).async {
            guard let request = self.request else { fatalError() }
            let handler = VNImageRequestHandler(cgImage: (self.originalImage?.cgImage)!, options: [:])
            do {
                try handler.perform([request])
            }catch {
                print(error)
            }
        }
   }

func visionRequestDidComplete(request: VNRequest, error: Error?) {
        DispatchQueue.main.async {
            if let observations = request.results as? [VNCoreMLFeatureValueObservation],
                let segmentationmap = observations.first?.featureValue.multiArrayValue {
                
                self.maskImage = segmentationmap.image(min: 0, max: 255)
                print(self.maskImage!.size)
                
                self.maskImage = self.maskImage?.resizedImage(for: self.originalImage!.size)
                if let image:UIImage = self.maskOriginalImage(){
                    print("Success")
                    self.outputImageView.image = image
                }
            }
        }
            
    }

func maskOriginalImage() -> UIImage? {
        if(self.maskImage != nil && self.originalImage != nil){
            let maskReference = self.maskImage?.cgImage!
            let imageMask = CGImage(maskWidth: maskReference!.width,
                                    height: maskReference!.height,
                                    bitsPerComponent: maskReference!.bitsPerComponent,
                                    bitsPerPixel: maskReference!.bitsPerPixel,
                                    bytesPerRow: maskReference!.bytesPerRow,
                                    provider: maskReference!.dataProvider!, decode: nil, shouldInterpolate: true)
            
            let maskedReference = self.originalImage?.cgImage!.masking(imageMask!)
            return UIImage(cgImage: maskedReference!)
            
        }
        return nil
    }