Moment invariants used as features for shape recognition has been widely used. The moments were computed using all the information of shape boundary associated with the interior region. This paper presents the theoretical improved moments computed based only on the shape boundary. Some invariants derived from improved moments in variation to translation, rotation, and scaling are presented. The computations of improved moment invariants based on chain code representation of a shape boundary can be done in real time. Experiments of discriminating country maps, industrial tools, and printed numerals by using improved moment invariants as features via graphical plots suggest that the improved moment invariants be good shape features close to human visual processing.