The key problem of planar dimension precision measurem en t handled in image manipulation is image object’s edge precision location. Aime d to this problem, a means is advanced that locates several scan lines’ edge in one dimension gray moment operators for precision sub-pixel edge location and g ets the result in statistics. The fundamental of the selection of the pixels for computation is confirmed at the foundation of analyzing edge pixels' distributi on. The feasibility can be confirmed in the experimen...