Convex Hull using JavaCV or WPIjavaCv

how would I convex hull a binary image with either JavaCV or WPIJavaCV?

Currently i am using:

    public static WPIContour] findConvexContours(WPIBinaryImage image)
    {
        image.validateDisposed();

        IplImage tempImage = IplImage.create(image.image.cvSize(), image.image.depth(), 1);

        opencv_core.cvCopy(image.image, tempImage);

        CvSeq contours = new CvSeq();
        opencv_imgproc.cvFindContours(tempImage, storage, contours, 256, opencv_imgproc.CV_RETR_LIST, opencv_imgproc.CV_CHAIN_APPROX_TC89_KCOS);
        ArrayList<WPIContour> results = new ArrayList();
        while (!WPIDisposable.isNull(contours)) {
            CvSeq convexContour = opencv_imgproc.cvConvexHull2(contours, storage, opencv_imgproc.CV_CLOCKWISE, 1);
            WPIContour contour = new WPIContour(opencv_core.cvCloneSeq(convexContour, storage));
            results.add(contour);
            contours = contours.h_next();
            
            
        }

        tempImage.release();
        WPIContour] array = new WPIContour[results.size()];
        return results.toArray(array);
    }

but it crashes the app when it runs.

Thanks,
Dimitri