Projective Mappings

Definition: A nonsingular projective mapping between two projective spaces is any mapping defined by multiplication of homogeneous coordinates by a full rank matrix. A collineation on ${I\!\!P}^{n}$ is an invertible projective mapping of ${I\!\!P}^{n}$ onto itself.

All projective mappings can be represented by matrices. As with homogeneous coordinate vectors, these are only defined up to a non-zero rescaling.