void drawConvexHull(IplImage * convexHullImage, CvPoint * handpoint,

//
//      引数:
//              convexHullImage : ConvexHull画像用IplImage
//              handpoint       : 手領域内の点の座標配列
//              hull            : ConvexHullの頂点のhandpointにおけるindex番号
//              hullcount       : ConvexHullの頂点の数
//
void drawConvexHull(IplImage * convexHullImage, CvPoint * handpoint,
		    int *hull, int hullcount)
{
    CvPoint pt0 = handpoint[hull[hullcount - 1]];
    for (int i = 0; i < hullcount; i++) {
	CvPoint pt = handpoint[hull[i]];
	cvLine(convexHullImage, pt0, pt, CV_RGB(0, 255, 0));
	pt0 = pt;
    }
}