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WHAT DOES LENA, A PLAYBOY CENTERFOLD in 1972, have in common with Yodaville, a simulated Middle East community near Yuma, Arizona?
Both Lena and Yodaville are discussed by James Vincent in “Keep It Clean,” London Review of Books, October 20, 2022. Also discussed there are automotive crash test dummies, the now-retired International Prototype Kilogram, and the Shirley Cards. I add The Teapot, already appearing here at SimanaitisSays.
James Vincent is reviewing Dylan Mulvin’s book Proxies: The Cultural Work of Standing In. Mulvin is Assistant Professor of Media and Communications at the London School of Economics. Here, in Parts 1 and 2 today and tomorrow, are tidbits gleaned from the LRB review, together with my usual Internet sleuthing (and first-hand fooling with The Teapot).
The Lena Image. Vincent writes of our world’s flood of images: “Yet despite their numbing infinite variety, these images all owe their sharpness and vibrancy to the legacy of a single photograph: a picture of a naked woman in a cluttered attic, a straw hat with feather trim worn at a rakish angle, face turned back over her shoulder to fix the camera with a bright, enigmatic eye. This is the Lena image (sometimes ‘Lenna’), which for nearly fifty years has been the default test subject for image compression algorithms, including the now ubiquitous JPEG format.”
Vincent writes, “Its use for this purpose began in the summer of 1973, when a group of researchers at the University of Southern California’s Signal and Image Processing Institute were casting around for a new picture to practise their work on…. Reports diverge as to how exactly the magazine found its way into the lab; some say the men sent out for a copy, others that a passing engineer happened to wander in while flicking through the pages of the November 1972 issue (coincidentally, the best-selling Playboy of all time). Either way, the group immediately lit on the centrefold: a picture of the Swedish-born model Lena Forsén, hat askew, clothes asunder.”
“To the men of SIPI she was merely a perfect test subject,” Vincent writes. “They tore off the top third of the page to fit her into their scanner, cropping the shot below the shoulder, removing the nudity, and rendering her as a digital image 512 x 512 pixels in size. And so Lena was enshrined for ever as the ‘patron saint of JPEGs’, used in countless research papers and academic journals to demonstrate the fidelity of algorithms.”
Why Lena? Vincent says, “First, there was the paper stock itself: glossy and high-quality, as Hugh Hefner demanded, it was ideal for scanning. Then there was the picture’s composition, which provides a number of visual challenges to test the mettle of any algorithm: different textures (flesh, hair, glass, wood, fabric); extremes of light and shadow; varying depths of focus; regions of flat colour (Lena’s bare shoulder) and fussy detail (the feather on the hat). Most important, though, it centres on a human face: since we know what a face should look like, any shortcomings in digital reproduction are quickly exposed.”
The Shirleys. Vincent writes of “the ‘Shirley Cards,’ distributed by Kodak to fulfill a similar role in commercial photography…. In the case of the Shirley Cards, the exclusive use of white models in early calibration tests meant that the world’s most popular film stock failed to capture the detail of other skin colours. ‘Whiteness moves through these standards with ease, whereas darker skin creates friction,’ Mulvin writes.”
“Beginning in the 1960s,” Vincent continues, “Kodak slowly began to fix this bias in its film, but not out of any sense of racial injustice: it was a response to complaints from furniture makers and chocolate sellers that Kodak cameras couldn’t properly capture their products’ hues.”
Automotive Crash Dummies. Vincent describes that “the dummy is a sit-in, rather than a stand-in, for the frail human body crumpled and twisted in cars and trucks. Its influence on the world has been similarly straightforward. Consider that, for many decades, crash test dummies were modelled on the dimensions of the ‘average man.’ ”
Vincent observes, “This meant that safety devices such as the three-point seat belt were optimised for male bodies. A study in 2011 found that, as a result, injury and fatality rates for women drivers was 47 per cent higher than for men in comparable crashes.”
Indeed, this shorcoming has been remedied: The original 50th-percentile male dummy from 1976 evolved into a full family to include a 95th-percentile male, a 5th-percentile female (albeit based on a male model), and several child dummies (these, particularly challenging to model because of a paucity of real data).
Tomorrow in Part 2, we’ll visit Yodaville, learn why the International Prototype Kilogram was retired, and how a teapot became a GMax primitive. ds
© Dennis Simanaitis, SimanaitisSays.com, 2022