Previous | Next --- Slide 52 of 86
Back to Lecture Thumbnails
gmoyer

How many point pairs would we need to find a unique solution for ${\bf P}$? Would we need one equation for each degree of freedom?

mpotoole

As mentioned in a previous lecture slide, there are 12 degrees of freedom with our camera matrix. Another way to view this is that there are 12 unknowns in this homogeneous linear system, and therefore there are 11 degrees of freedom once we constrain the norm of our unknowns to 1.

So how many point pairs are required to find a unique solution? Typically, you need one equation per degree of freedom. In this case, since we get two equations per 3D-2D correspondence, we need six correspondences to solve for our camera matrix.