In this paper, spherical harmonics are proposed as shape descriptors for 2d images. We introduce the concept of connectivity; 2d images are decomposed using connectivity which is followed by 3d model construction. Spherical harmonics are obtained for 3d models and used as descriptors for the underlying 2d shapes. Difference between two images is computed as the Euclidean distance between their spherical harmonics descriptors. Experiments are performed to test the effectiveness of spherical harmonics for retrieval of 2d images. Item S8 within the MPEG-7 Still Images Content Set is used for performing experiments; this dataset consists of 3621 still images. Experimental results show that the proposed descriptors for 2d images are effective.