function DecideOberlap(BBox_x1, BBox_y1, BBox_x2, BBox_y2, BBox_gt_x1, BBox_gt_y1, BBox_gt_x2, BBox_gt_y2)

     x1 = BBox_x1;

     y1 = BBox_y1;

     width1  = BBox_x2 - BBox_x1;

     height1 = BBox_y2 - BBox_y1;

     x2 = BBox_gt_x1;

     y2 = BBox_gt_y1;

     width2  = BBox_gt_x2 - BBox_gt_x1;

     height2 = BBox_gt_y2 - BBox_gt_y1;

     endx     = math.max(x1+width1, x2+width2);

     startx     = math.min(x1, x2);

     width     = width1 + width2 - (endx - startx);

     endy = math.max(y1 + height1, y2 + height2);

     starty = math.min(y1, y2);

     height = height1 + height2 - (endy - starty);

     if width<= or height<= then

         ratio = ;

     else

         Area = width*height;

         Area1 = width1*height1;

         Area2 = width2*height2;

         ratio = Area/Area1;

     end

     return ratio 

 end