Revisiting Motion Parallax as a Source of 3-D Information

There are many similarities between binocular disparity and motion parallax as sources of information about the structure and layout of 3-D objects and surfaces. The former can be thought of as a transformation that maps one eye's image onto the other while the latter is a transformation that maps the changes in one eye's image over time. There are many empirical similarities in the ways we use the two sources of information but there are also significant differences. A consideration of those differences leads to the conclusion that, rather than seeing motion parallax as a close analogue of binocular stereopsis, motion parallax is better thought of as a special case of the kinetic depth effect in which the depth order of the depicted 3-D object or surface can be disambiguated by vertical perspective information.