Lena Söderberg or Lena is the name given to a 512×512 pixel standard test image which has been in use since 1973,and was originally cropped from the centerfold of November 1972 issue of Playboy magazine. It is a picture of Lena Söderberg, a Swedish model, shot by photographer Dwight Hooker. The image is probably the most widely used test image for all sorts of image processing algorithms (such as compression and denoising) and related scientific publications.The anglicised version "Lenna" of Lena Söderberg's actual name comes from the Playboy article where Playboy changed the original "Lena".
Alexander Sawchuk estimates that it was in June or July of 1973 when he, then an assistant professor of electrical engineering at the USC Signal and Image Processing Institute (SIPI), along with a graduate student and the SIPI lab manager, was hurriedly searching the lab for a good image to scan for a colleague's conference paper. They had tired of their stock of usual test images, dull stuff dating back to television standards work in the early 1960s. They wanted something glossy to ensure good output dynamic range, and they wanted a human face. Just then, somebody happened to walk in with a recent issue of Playboy.
Dwight Hooker is a photographer for Playboy magazine. He was, at times, described as a master of the sensual and the erotic along with photographers Helmut Newton and J. Frederick Smith. Lena Söderberg, the standard test image for image processing algorithms (such as compression and denoising) and related scientific publications, was photographed by him.
Coincidentally, Playboy states the issue (November 1972) was its best-selling issue ever, having sold 7,161,561 copies as of May 2006, and the Lenna centerfold appears briefly in Woody Allen's film Sleeper released the following year.