How a ‘Playboy’ Centerfold Became Part of the Creation of the JPEG

How a ‘Playboy’ Centerfold Became Part of the Creation of the JPEG

In her new book, How Sex Changed the Internet and the Internet Changed Sex: An Unexpected History, Samantha Cole traces the twisting history of the “Lena Centerfold,” an image from Playboy that became an international standard for training computers to recognise images. The image, taken in 1972, persisted for decades in computer science, even inspiring op-eds in 2015 from engineering students. The image and its ubiquity came to symbolise sexism and male domination for many young women entering the field.

And as for the woman herself, Lena? Read on to see how she became a stranger to her own image.

In 1972, Lena Sjööblom took a modelling gig with Playboy, posed for a nude photo, got the paycheck, and moved on with her life.

It was the first and last time Lena posed nude. She turned down a personal invitation from Hugh Hefner to visit his mansion. She took more gigs with Kodak, posing for “Shirley Cards” (named for the first model to pose for one, a white, brunette Kodak employee named Shirley Page) that helped technicians calibrate the lighting and colour balances on film. Her friends thought the Playboy anecdote was a fun bit of trivia, but for Lena that photo was in the past.

But for the rest of the world, Lena was changing the internet.

A few months after that issue of Playboy hit stands, at the University of Southern California’s Signal and Image Processing Institute, electrical engineer Alexander Sawchuk and his team were working on image-processing algorithms for computers. They used “test images” — a specific set of photos shared across imaging labs, so that each lab was working from the same standard — to put their image compression algorithms through their paces. The team’s work would eventually contribute to the development of the JPEG file format, one of the most common image formats we still use today.

None of the historical retellings of Lena’s story seems to include (or wants to reveal) who, exactly, brought the Playboy to work that day. But most accounts agree that when they needed a new image to scan into a Hewlett-Packard 2100 minicomputer, the November 1972 issue of Playboy was chosen for convenience. They were bored with the old test images and wanted a photo with a human face, interesting textures, and a glossy finish to test the limits of the technology. The centerfold was perfect.

They cut Lena’s photo out of the magazine from her shoulders up, effectively making the photo safe for work. Some have attributed the crop job to taste or tact; more likely, it was a technical matter. The top 5.12 inches of the page fit into the Muirhead wirephoto scanner, making a 512 x 512 pixel image.

The image suited their purposes so well, they gave the scans to other researchers working on similar image processing tasks, and it eventually travelled so widely that it was accepted as a standard across the industry. There were other test images in use at the time, but Lena became the established standard that labs around the country could agree on. Part of her enduring legacy is propelled by controversy. Over the course of two decades, Lena’s image spread quietly and uncontrollably before Playboy even noticed. By the time the publisher did notice, when the trade magazine Optical Engineering put Lena on its July cover in 1991, it was too late for them to try to reel her back in — the publisher gave permission for educational and research purposes instead.

But copyright violation wasn’t the cause for contention. With the tech world’s dot-com explosion offering promising futures for all at the same time, women were world-building, moderating, and hosting BBS servers, MUDs, and their own websites right there with the old boys’ club. But women still weren’t seen as equal competitors and colleagues with their male counterparts in the computing workforce. The Lena test image, some argued, was just another artefact of the carelessly patriarchal thinking that had ruled the last thirty years. Some demanded the image be retired.

Editor-in-chief of industry journal IEEE Transactions on Image Processing David Munson Jr. wrote an open letter addressing those complaints in 1996. His verdict was not to censor uses of Lena, but if there were other, equally useful options available, researchers should opt for those instead. “In cases where another image will serve your purpose equally well, why not use that other image?” Munson wrote. The issue appeared settled.

For years, Lena herself had no idea any of this was happening. She was living quietly in Sweden, unaware of the ruckus her photoshoot had stirred among computer geeks in the US. It wasn’t until she was invited to the Fiftieth Annual Conference of the Society for Imaging Science and Technology in 1997 that she understood the scope at which her image was being used, let alone as the gold standard for more than twenty years. She’d never even accessed the internet until then.

The conference was a surreal experience for Lena, mainly because all these people, mostly white male engineers, had never considered her real, physical existence before. They were meeting the Weird Science woman of their academia days, a set of pixels and colours they’d studied closely but never saw as part of a whole human.

The attitudes of experimentation on women’s bodies and images push women out of the industry before they have a chance to start. In 2015, Maddie Zug, a senior at the Thomas Jefferson High School for Science and Technology, wrote an op-ed to the Washington Post about her experience as one of a handful of female peers assigned to use the Lena image for a coding project. The teacher warned them not to look up the image. Of course, the first thing everyone in that computer lab did was search for the original and pull up the whole centerfold on their screens.

“At the time I was 16 and struggling to believe that I belonged in a male-dominated computer science class,” Zug wrote. “I tried to tune out the boys’ sexual comments. Why is an advanced science, technology, engineering and mathematics school using a Playboy centerfold in its classrooms?”

Today, female technology students still have many of the same complaints as they have from the beginning: Gender wage gaps, male-skewed advancement opportunities, and sexist attitudes still thrive in tech. Having to sit through a computing class where a story about a huddle of men and their unaware Playmate is the week’s lesson is salt in the wound.

Though now in her seventies and a grandmother, Lena seems to hold few strong opinions on the use of her image. Though the test image still haunts our modern machines, like a nostalgic nod, current image processing researchers occasionally use her in their papers. But in recent years, several journals and institutions announced they would outright ban submissions that featured Lena, including the Optical Society, the Society for Industrial and Applied Mathematics, and the entire family of around 150 Nature journals.

For some in the image processing world, Lena has simply outlasted her usefulness. In his 2018 farewell letter as editor-in-chief of IEEE Transactions, Scott Acton urged his colleagues to think outside the old standbys. The Lena crop contains around 260,000 pixels — pretty good for her time. An image from the iPhone 11, released in 2019, contains more than 12,000,000.

Five years after Lena’s Miss November issue, the Apple II would become the first graphics-capable personal computer to enter American homes. Before image processing reached the masses, however, people made do with what they had: text, assembled into mosaic.

Adapted from How Sex Changed the Internet and the Internet Changed Sex: An Unexpected History by Samantha Cole. Workman © 2022

Image: Courtesy of Workman
Image: Courtesy of Workman