The Perception of Visual Depth by David Marr

David Marr's concept of visual depth perception explains how the brain interprets three-dimensional structure from two-dimensional images captured by our eyes. He proposed a series of processing steps: first, extracting basic features like edges and shading; then constructing a "primal sketch" that identifies and organizes contours; and finally building a detailed 3D model of the environment using depth cues like disparity, perspective, and shading. This approach highlights how the brain transforms visual signals into meaningful spatial understanding, enabling us to judge distances and perceive depth accurately.