public void TrainImages()
        {
            string path = Application.StartupPath + @"/../../Images/";

            string[] files = Directory.GetFiles(path, "*.jpg", SearchOption.AllDirectories);
            //   int[] labelsDb = _context.Labels.Select(_ => _.LabelNumber).ToArray();
            List <int> labelsDb = new List <int>();

            Mat[] matImages = new Mat[files.Length];



            for (int i = 0; i < files.Length; i++)
            {
                matImages[i] = new Image <Gray, byte>(files[i]).Mat;
                string[] strings = files[i].Split('-');
                string   number  = strings[strings.Length - 1].Split('.')[0];
                labelsDb.Add(int.Parse(number));
            }


            VectorOfMat images = new VectorOfMat(matImages);
            VectorOfInt labels = new VectorOfInt(labelsDb.ToArray());

            faceRecognizer.Train(images, labels);
            faceRecognizer.Write(Application.StartupPath + @"/../../Images/eigenRecognizer.yml");
            fisherRecognizer.Train(images, labels);
            fisherRecognizer.Write(Application.StartupPath + @"/../../Images/fisherRecognizer.yml");
            LBPHFaceRecognizer.Train(images, labels);
            LBPHFaceRecognizer.Write(Application.StartupPath + @"/../../Images/lpbhRecognizer.yml");
            isTrained = true;
        }
        public async Task TrainAsync()
        {
            await Task.CompletedTask;

            var files = Directory.GetFiles(DataFolder, "*.image");

            if (files?.Length > 0)
            {
                var count = files.Length;

                var counter = 0;

                var faceImages = new Mat[count];

                var faceLabels = new int[count];

                foreach (var file in files)
                {
                    var faceImage = new Image <Gray, byte>(file);

                    faceImage = ResizeImage(faceImage);

                    faceImages[counter] = faceImage.Mat;

                    faceLabels[counter] = int.Parse(Path.GetFileName(file).Split('.').First());

                    counter++;
                }

                //_fisherFaceRecognizer.Train(faceImages, faceLabels);

                //_fisherFaceRecognizer.Write(FisherTrainingDataPath);

                _lbphFaceRecognizer.Train(faceImages, faceLabels);

                _lbphFaceRecognizer.Write(LBPHTrainingDataPath);
            }
        }