Monocular Depth Cues
1. Linear Perspective
Linear perspective effects are probably the most familiar to us. They cause objects that are farther away to appear to be smaller, and lines that are parallel to appear to converge in the distance. Mathematically, this effect is modeled as a rational linear function (i.e., the quotient of two linear functions) and can be represented as a projective space operation using a 4x4 matrix. We shall review the definition and use of this representation later in this lesson in the context of deriving the mathematics of stereo projections.
Linear perspective is a monocular cue because the effects are manifested as actual differences in distance and size that require only a single eye to perceive. In this image, for example, the white road lines and the broken white center line are parallel, but seem to converge in the distance.
