[Question] What is purpose to call face_detector()?

[takuya-takeuchi]

• face_recognition version: N/A
• Python version: N/A
• Operating System: N/A

Description

I am porting your library to C# on https://github.com/takuya-takeuchi/FaceRecognitionDotNet. Then, contributor points

def _raw_face_locations(img, number_of_times_to_upsample=1, model="hog"):
    """
    Returns an array of bounding boxes of human faces in a image

    :param img: An image (as a numpy array)
    :param number_of_times_to_upsample: How many times to upsample the image looking for faces. Higher numbers find smaller faces.
    :param model: Which face detection model to use. "hog" is less accurate but faster on CPUs. "cnn" is a more accurate
                  deep-learning model which is GPU/CUDA accelerated (if available). The default is "hog".
    :return: A list of dlib 'rect' objects of found face locations
    """
    if model == "cnn":
        return cnn_face_detector(img, number_of_times_to_upsample)
    else:
        return face_detector(img, number_of_times_to_upsample)

face_detector(img, number_of_times_to_upsample) should be changed to

private IEnumerable<MModRect> RawFaceLocations(Image faceImage, int numberOfTimesToUpsample = 1, Models model = Models.Hog)
        {
            switch (model)
            {
                case Models.Cnn:
                    return CnnFaceDetectionodelV1.Detect(this._CnnFaceDetector, faceImage.Matrix, numberOfTimesToUpsample);
                default:
                    {
                        using (var pyr = new PyramidDown(2))
                        {
                            var rects = new List<MModRect>();
                            var image = faceImage.Matrix;
                            var levels = numberOfTimesToUpsample;
                            while (levels > 0)
                            {
                                levels--;
                                DlibDotNet.Dlib.PyramidUp<PyramidDown>(image, 2);
                            }
                            var dets = this._CnnFaceDetector.Operator(image);
                            foreach (var d in dets.First())
                            {
                                var drect = pyr.RectDown(new DRectangle(d.Rect), (uint)numberOfTimesToUpsample);
                                d.Rect = new Rectangle((int)drect.Left, (int)drect.Top, (int)drect.Right, (int)drect.Bottom);
                                rects.Add(d);
                            }
                            return rects;
                        }
                    }
            }
        }

(Sorry to use C# rather than python.)

The 2nd argument 'number_of_times_to_upsample' does not suit to face_detector operator. On original dlib, the 2nd argument face_detector operator takes double threshold. This value is threshold for searching saliency image rather than indicating number of times to upsampling. Was this done intentionally?

What I Did

N/A

[takuya-takeuchi]

I'm very sorry. It is not issue.