"Pixel: a biography"

When on a trip, you never know when the flight attendant is going make the announcement, "ummm, we have a slight problem with the plane, does anyone know anything about pixels?"

And you will clear your throat and....

From Aeon:

Alvy Ray Smith was born before computers, made his first computer graphic in 1964, cofounded Pixar, 

was the first director of computer graphics at Lucasfilm, and the first graphics fellow at Microsoft. He is 

the author of A Biography of the Pixel (2021).

An exact mathematical concept, pixels are the elementary particles of pictures, based on a subtle unpacking of infinity

I have billions of pixels in my cellphone, and you probably do too. But what is a pixel? Why do so many people think that pixels are little abutting squares? Now that we’re aswim in an ocean of zettapixels (21 zeros), it’s time to understand what they are. The underlying idea – a repackaging of infinity – is subtle and beautiful. Far from being squares or dots that ‘sort of’ approximate a smooth visual scene, pixels are the profound and exact concept at the heart of all the images that surround us – the elementary particles of modern pictures.

This brief history of the pixel begins with Joseph Fourier in the French Revolution and ends in the year 2000 – the recent millennium. I strip away the usual mathematical baggage that hides the pixel from ordinary view, and then present a way of looking at what it has wrought.

The millennium is a suitable endpoint because it marked what’s called the great digital convergence, an immense but uncelebrated event, when all the old analogue media types coalesced into the one digital medium. The era of digital light – all pictures, for whatever purposes, made of pixels – thus quietly began. It’s a vast field: books, movies, television, electronic games, cellphones displays, app interfaces, virtual reality, weather satellite images, Mars rover pictures – to mention a few categories – even parking meters and dashboards. Nearly all pictures in the world today are digital light, including nearly all the printed words. In fact, because of the digital explosion, this includes nearly all the pictures ever made. Art museums and kindergartens are among the few remaining analogue bastions, where pictures fashioned from old media can reliably be found.

Almost everyone in the sciences and technologies knows Fourier. We use his great wave idea every day. But most know very little about the man himself. Few are aware that he was almost guillotined for his role in the French Revolution in the 1790s. Or that he went to Egypt with Napoleon Bonaparte in the expedition that revealed the Rosetta Stone. Or that Napoleon exiled him to Grenoble to keep him – or, more importantly, his knowledge of Napoleon’s military embarrassments in Egypt – out of Paris. While in exile, he mastered his great musical idea. Only when Napoleon himself was finally exiled to St Helena could Fourier return to Paris.

It’s common knowledge that music is a sum of sound waves of different frequencies (pitches) and amplitudes (loudnesses). It was Fourier who taught us that all audio is made up of waves too. He taught us that a one-dimensional (1D) signal, such as a sequence of sounds, is a sum of beautiful regular waves, like those in Figure 1 below:

Figure 1

Importantly for the pixel, Fourier taught us that a two-dimensional (2D) signal – a picture, say – is also a sum of regular waves, like those in Figure 2 below. They are 1D waves extruded out of the page and viewed from above the ripples. Fourier told us that you can add such corrugations together to get any picture – of your child, for example. It’s all music.

Figure 2

Perhaps the most unexpected person in this story – at least for readers in the United States – is Vladimir Kotelnikov, the man who turned Fourier’s idea into the pixel. Born in Kazan of a centuries-long line of mathematicians, Kotelnikov lived through the entire Soviet era – the First World War, the Russian Revolution, the Second World War and the Cold War. The NKVD, forerunner of the Soviet security agency the KGB, tried to imprison him twice during Stalin’s time, but a protector – Valeriya Golubtsova – saved him both times. She could because her mother was a personal friend of the Russian revolutionary Vladimir Lenin, and she herself was the wife of Georgi Malenkov, Stalin’s immediate successor as leader of the Soviet Union....

....MUCH MORE