But the story behind this photograph is an unusual one! It comes from the cover of the November 1972 issue of Playboy, on which the young Swedish woman Lena Sjööblom-Soderberg, then aged 21, was posing. A few months after it was published, the photograph was used to test an algorithm developed by Alexander Sawchuk and his team at the University of Southern California (United States). Although the exact circumstances in which a copy of Playboy found its way into a computer science laboratory remain unclear, we do know that the researchers were impressed by the photograph's rich combination of contrasts, colors and textures, which made it an ideal candidate for evaluating their new image-processing technique. Many of their colleagues followed suit, testing their own algorithms on the image—and they continue to do so today.
Controversy arose fairly early on: is using an image taken from Playboy inappropriate in a professional setting, or even misogynistic? The debate is ongoing, and although "Lena" will always be the "first lady" of the Internet, more and more researchers are now choosing other images for their tests.