Camera.FaceDetectionListener

MyFaceDetectionListener.java

public class MyFaceDetectionListener implements Camera.FaceDetectionListener {
    private Matrix m = new Matrix();
    private RectF rect = new RectF();

    // Call this before startFaceDetection().
    // targetWidth and targetHeight are usually size of view which shows camera preview.
    public void setup(boolean useFrontCamera, int displayOrientation, float targetWidth, float targetHeight) {
        m.setScale(useFrontCamera ? -1 : 1, 1);
        m.postRotate(displayOrientation);
        m.postTranslate(1000, 1000);
        m.postScale(targetWidth / 2000f, targetHeight / 2000f);
    }

    @Override
    public void onFaceDetection(Camera.Face[] faces, Camera camera) {
        for (Camera.Face face : faces) {
            rect.set(face.rect);
            m.mapRect(rect);
            processFace(rect);
        }
    }
    
    public void processFace(RectF rect) {
      // Do something with rect.
    }
}