The Life and Times of ‘Digital Light,’ a book review: A Biography of the Pixel

This is the physics and family history of everything that goes into visuals on screens, from cave drawings to Toy Story, through excursions to Egypt, Russian gulags, and a hundred other directions that manage to be both strangely relevant and typically intriguing.

Pixels are not the little light dots that appear on your computer screen (strictly speaking, we should call those display elements). Instead, they’re a single-point sample of a visual field with position and colour. Or, to put it another way, they’re the invisible digital bits that represent what Alvy Ray Smith refers to as “digital light” (the book’s original title) — the technology that allows you to see digital text, drawings, photographs, videos, movies, and TV shows because they’re rendered visible through computation. He describes the pixel as a “deep and abstract idea that connects our contemporary world together,” according to him.

Smith must understand: as a co-founder of Pixar, he was instrumental in the development of computer graphics, from sprites to the HSV colour space model (and he sold his second company, Altamira, to Microsoft, where it became the foundation for Microsoft’s multimedia authoring tools like PhotoDraw, and he was named Microsoft’s first graphics fellow).

Smith had spent the past ten years studying and creating A Biography of the Pixel, a book that explains the principles underlying the digital pictures we see every day on our computers, since few people understand what they are or how they operate (and even experts in the field rarely look at the big picture of how it all fits together). Even Smith had no idea that the initial pixels trace back to the first computers when he began working on the book. He goes back much deeper, to the earliest animation, which was a pig painted on the wall of a Palaeolithic cave with additional legs, making it seem to be running in the flickering firelight.

There is a great deal of mathematics involved with computer graphics, and Smith’s website includes an additional set of annotations with crucial equations and more in-depth analyses of underlying knowledge. Even without them, the book’s first section rambles through Napoleonic and post-revolutionary Russian history, introducing Fourier’s frequencies and waves, as well as Kotelnikov and Shannon‘s sampling theory, which explains how discrete digital bits like pixels can represent the visual world, where visual frequencies (not to be confused with light waves) are continuous and crammed with values.

A broad range

Smith covers a broad variety of topics in the history of science and technology, including rockets and espionage, Tom Stoppard plays, Alan Turing, von Neuman, and vocoders (and cinema). That’s because he’s teaching not just the history of display technology, but also information theory and his own hypothesis. This is because significant technological advances usually involve not only individuals with breakthrough ideas, but also disruptive chaos that fuels the need for the breakthrough, as well as a tyrant (anyone from Napoleon to Walt Disney) who intentionally or accidentally creates the space in which the breakthrough can occur (be that exile to a provincial town or providing funding and making demands).

You shouldn’t have to agree with Smith’s historical theory to find all of this entertaining and instructive. His digital light hypothesis is particularly controversial since no one has sat down and compiled all of the contributions and linkages that go into how pictures are shown on screens (in terms of information rather than the physics of light).

Pixels are important in many areas of computer graphics that aren’t covered in detail in the book, including digital photography, image processing, user interfaces, computer games, CAD, flight simulators, virtual and augmented reality, and virtual and augmented reality. Smith makes several important distinctions, such as the difference between ‘taking’ and’making’ pixels, but as the book progresses, he focuses more and more on the technology that generate digital and, in particular, computer-animated films.

A Biography of the Pixel is a dense and carefully documented chronicle of the 30 years of technology that led to the advent of digital filmmaking (and a century or so before that) as well as a reference book describing how and why that technology works. You may keep track of the abundance of information by using flow charts to trace the contributions of various persons and initiatives to the creation of cinema, the first computer systems, or digital movies. What qualifies as the world’s first computer? Who invented the first moving image, animated cartoon, and colour pixels? (If the book’s breadth, reach, and sheer depth get to you, the ending part repeats all of the important concepts so you can see how they fit together.)

Anecdotes from history

In this book, Smith describes the narrative of the people who came up with the ideas of Bezier curves, motion blurs, alpha channels, and shaders, as well as stories such as the Klingon simulation of the Genesis Device in Star Trek II: The Wrath of Khan being there merely to attract George Lucas’ attention. Along the way, there’s a lot of Pixar history, since Smith, along with Ed Catmull and the other Pixar pioneers, was involved in a number of computer graphics “firsts.” He also offers some convincing suggestions about why, despite having so many expertise and innovations, Xerox PARC lost out on colour computing the way it missed out on personal computing.

Smith then recounts his own detective work, interviewing other computer graphics pioneers to piece together the field’s early history, along with entertaining tales and personal recollections that reveal many unsung heroes.

Your knowledge of computer graphics will grow no matter how deep your dive, whether it be the discovery that pixels that appear when you zoom into a digital picture aren’t really pixels or the 1975 oil tanker simulation housed in a brick structure that looks like a ship.

This is a fascinating read that is actually three or four volumes bundled into one, with as much history, genealogy, and research as biography. Smith says about pixels and digital light, “My sincere aim is that you comprehend this bit of magic and be astounded by how it works.” Some of the twists and turns along the way may surprise you, but you’ll emerge with a far broader understanding of what goes into the digital material you’ll be looking at next.