Speaker: 李楠，深圳大学

Title: Singular Analysis for the P3P Problem

Language: Chinese

Time & Venue: 2026.07.21 15:30-16:30 思源楼525

Abstract: The P3P problem, which determines the pose of a perspective camera from three 3D-to-2Dpoint correspondences, is fundamental in computer vision. The number of P3P solutions mayvary under different configurations, i.e. relative arrangement of three 3D points and thecamera center. Under singular configuration, the P3P problem possesses a multiple solutionand P3P solvers lead to inaccurate and unstable results. In this talk, we use some tools fromcomputational algebraic geometry to stratify the singular configurations with respect to themultiplicity. We show that, for a valid triangle of three 3D points, the camera center must lieon the "danger cylinder" to be a P3P solution of multiplicity $\geg2s, and for multiplicity$\geq3$, it must lie either on one of three "Morley generatrices" or on the circumcircle, andfor multiplicity $\geq4$, it must lie on the circumcircle. These findings offer new insights intothe geometric understanding of the P3P problem and provide a theoretical basis forimproving the accuracy and stability of P3P solvers.