import static org.bytedeco.javacpp.opencv_imgproc.CV_BGR2GRAY;
import static org.bytedeco.javacpp.opencv_imgproc.cvtColor;
import static org.bytedeco.javacpp.opencv_objdetect.CASCADE_SCALE_IMAGE;

import org.bytedeco.javacpp.opencv_core;
import org.bytedeco.javacpp.opencv_core.Mat;
import org.bytedeco.javacpp.opencv_objdetect;

import ij.ImagePlus;
import ij.gui.Roi;
import ij.plugin.filter.PlugInFilter;
import ij.plugin.frame.RoiManager;
import ij.process.ImageProcessor;
import ijopencv.ij.ImagePlusMatConverter;
import ijopencv.opencv.RectRoiConverter;

/**
 *
 * @author jonathan
 */
public class FaceDetectionJ implements PlugInFilter
{

    ImagePlus       imp;

    @Override
    public int setup(String arg, ImagePlus imp)
    {
        this.imp = imp;
        return DOES_RGB;
    }

    @Override
    public void run(ImageProcessor ip)
    {
        // Converter
        ImagePlusMatConverter ic = new ImagePlusMatConverter();
        opencv_core.Mat img2 = ic.convert(imp, opencv_core.Mat.class);

        // Detect the faces and store them as an array of rectangles
        detectFaces(img2);

    }

    public opencv_core.RectVector detectFaces(opencv_core.Mat image)
    {
        RectRoiConverter rc = new RectRoiConverter();

        opencv_core.Mat img_gray = new opencv_core.Mat();
        cvtColor(image, img_gray, CV_BGR2GRAY);

        opencv_objdetect.CascadeClassifier faceclassifier = new opencv_objdetect.CascadeClassifier(
                "haarcascade_frontalface_alt.xml");
        // and eyes
        opencv_objdetect.CascadeClassifier eyeclassifier = new opencv_objdetect.CascadeClassifier(
                "haarcascade_eye.xml");

        opencv_core.RectVector rv = new opencv_core.RectVector();

        faceclassifier.detectMultiScale(img_gray, rv, 1.1, 2, CASCADE_SCALE_IMAGE, new opencv_core.Size(30, 30),
                new opencv_core.Size(500, 500));

        faceclassifier.close();


        // Add rectangles to ROI Manager
        RoiManager rm = new RoiManager();
        rm.setVisible(true);
            for (int i = 0; i < rv.size(); i++)
            {
                Roi r = rc.convert(rv.get(i), Roi.class);
                rm.add(imp, r, 0);

                // How do I search for eyes withing the ROI?
                // Something like this?
                //eyeclassifier.detectMultiScale(ROI in img_gray?);
                //for (int j = 0; j < ROI?; j++)
                //{
                //  And here? Like above? Roi e = ??
                //}
            }

        return rv; // and the function does actually not need to return anything anymore, right?
    }
}