Traditional subpixel edge location algorithms use local model to realize precise edge location.Which leads to side effects such as Zigzag effect and discontinuous edges.We present a new subpixel edge location algorithm based on partial differential equation(PDE)

where level-set reconstruction(LSR) is introduced to smooth edge along their tangents.Anchor and topology constraints are used to avoid over-smoothing and keep edge topology structures.Subpixel edge location experiments with both geometric and natural image show that this method can remove zigzag effect while keeping edge smoothness and continuity.