David L. Waltz; helped to develop modern computer

e. barroso/columbia engineering

NEW YORK - David L. Waltz, a computer scientist whose early research in information retrieval provided the foundation for today’s Internet search engines, died Thursday in Princeton, N.J.

The cause was brain cancer, said his wife, Bonnie. He died at the University Medical Center at Princeton.

During his career as a teacher and a technologist at startup companies as well as large corporate laboratories, Mr. Waltz, 68, made fundamental contributions to computer science in areas ranging from computer vision to machine learning.


He developed a basic technique for computers to render three-dimensional scenes accurately. As part of his PhD dissertation at the Massachusetts Institute of Technology, he developed an algorithm that could extract a rich three-dimensional understanding of a scene from line drawings with shadows.

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The 3-D research was seminal in the fields of computer vision and artificial intelligence.

At MIT, Mr. Waltz was taught by Marvin Minsky, a pioneer in artificial intelligence. Mr. Waltz graduated in 1972, then taught computer science at the University of Illinois at Urbana-Champaign and, later, at Brandeis University in Massachusetts.

But it was as a member of a group of researchers at the Thinking Machines Corp., in Cambridge, that Mr. Waltz made his breakthrough in information retrieval. By joining the company, in 1984, Mr. Waltz gained access to computers that by ’80s standards held vast amounts of fast random-access memory, up to 512 megabytes.

“For the first time it was possible to use simple algorithms with lots and lots of data,’’ said Brewster Kahle, a computer scientist who directs the Internet Archives and was one of the Thinking Machines researchers.


Access to that database was crucial to Mr. Waltz’s development of a technique known as memory, or “case based,’’ reasoning. It revolutionized the way computers recognized characters, words, images and later, even voices.

The technique transformed the field of artificial intelligence and also greatly advanced voice recognition and machine vision technology. And it led directly to the “big data’’ and data-science approaches that are essential tools for search engines, allowing them to sift through large collections of information to improve accuracy and relevance.

Mr. Waltz obtained both undergraduate and graduate degrees at MIT in electrical engineering. He lived in Princeton.

Besides his wife, he leaves a brother, Peter; a son, Jeremy; a daughter, Vanessa Waltz, and a granddaughter.