A Tighter Lower Bound on the Spetsakis–Aloimonos Trilinear Constraints

摘要

This note provides a tighter lower bound on the Spetsakis–Aloimonos trilinear constraints used in the linear algorithm for point and line-based structure from motion. It was claimed that onlythreeindependent equations were available for a given point match between three views in the linear algorithm. This note shows that there in fact existsfourindependent equations. It has an important consequence: The minimum number of points required for the linear algorithm isseveninstead ofnine.