Homogeneous coordinates Projective coordinates. = of projective space. is the scale factor. Convert back to cartesian coords - (x, y, w) ←> (x/w, y/w). Allows easy operations on coord spaces using matrices If w = 0, it’s called ideal point. Ideal points do not have inhomogeneous equivalents Pinhole projection Similar calculation as homogeneous. Multiply by focal length Invariance to scaling - k(x, y, w) ←> (x/w, y/w)