Textbook of AI

1945–1980, Neuroscientist, computational vision pioneer

David Courtnay Marr was a British neuroscientist whose posthumously-published Vision: A Computational Investigation into the Human Representation and Processing of Visual Information (1982) reshaped the study of perception. Marr proposed three levels of analysis for any information-processing system: the computational (what is it doing and why?), the algorithmic (what representations and what algorithm?), and the implementation (how is it physically realised?). The framework remains a touchstone of cognitive science, computational neuroscience and AI methodology.

Marr's specific theory of vision proposed a hierarchy of representations: the primal sketch (edges, blobs, terminations), the 2½-D sketch (depth and orientation in the viewer-centred frame), and the 3-D model (object-centred volumetric representation). The computational stages identified, edge detection by zero-crossings of Laplacian-of-Gaussian filters, stereo matching by matching across scales, directly anticipated layers of modern convolutional neural networks.

He died of leukaemia in 1980 at the age of 35. The volume that secured his enduring influence in vision was completed and edited by his colleagues from his late drafts.