THE PERSPECTIVE VIEW OF 3 POINTS

In this paper we focus on the perspective view of three noncollinear points whose image-to-object correspondence is known. Such measurements are known to be ambiguous, resulting in as many as four possible solutions to the perspective three-point problem. Although there can be four solutions, it is quite often the case that there are only two solutions. We provide a geometric explanation of the camera-triangle configurations that cause one, two, three, or four solutions. The results also provide a justification for the common wisdom that there are "usually" two solutions.