A novel technique for shape coding of a digital object based on its inner and/or outer isothetic polygonal shape, is proposed. The method uses a multigrid background for several applications including digital image visualization and retrieval with varying levels of accuracy. The elegance of the proposed shape code lies in capturing the shape of the objects present in an image from their gross appearances to finer details with a set of hierarchical isothetic polygons that tightly envelop (cover) the objects from outside (inside). Experimental results demonstrate the strength and efficiency of the proposed scheme.