extractFeatures static method

List<double>? extractFeatures(Face face)

Extract a normalized feature vector from a Face.

Returns null if the face has no contour data (ensure ML Kit is configured with enableContours: true).

Implementation

static List<double>? extractFeatures(Face face) {
  final box = face.boundingBox;
  if (box.width == 0 || box.height == 0) return null;

  final features = <double>[];

  for (final type in _contourTypes) {
    final contour = face.contours[type];
    if (contour == null) return null;

    for (final point in contour.points) {
      // Normalize to 0.0–1.0 relative to bounding box.
      features.add((point.x - box.left) / box.width);
      features.add((point.y - box.top) / box.height);
    }
  }

  if (features.isEmpty) return null;
  return features;
}