•Problem:
perspective is non-linear.
•Solution:
Homogenous coordinates.
–Represent
points in plane as (x,y,w)
–(x,y,w), (kx, ky, kw), (x/w, y/w, 1) represent same point.
–If we
think of these as points in 3D, they lie on a line through origin. Set of 3D points that project to
same 2D point.