Lenna Sjööblom’s Role in Image Compression History

Every selfie you take, every photo you post, and every movie you stream owes something—surprisingly—to an image pulled from a 1972 Playboy centerfold. The woman in the photo, Lenna Sjööblom, had no connection to computing, yet her image became an unlikely icon in the tech world.

In the mid-1970s, researchers at the University of Southern California's Signal and Image Processing Institute were seeking a high-quality, widely available image to use as a standard test in digital image processing. One engineer tore out a portion of Lenna’s centerfold and digitised it. That image—cropped to focus on her face and shoulder—became known as the "Lenna" image.

It is precisely this contradiction that makes her story so curious: a former Playboy model becoming a staple in programming labs, used by researchers who spent countless hours in front of screens refining image compression algorithms. Lenna’s photo served as a consistent benchmark to assess whether these algorithms preserved visual quality after compressing an image.

This work laid the foundation for formats like JPEG (Joint Photographic Experts Group) and MPEG (Moving Picture Experts Group)—technologies that make it possible to store thousands of images on your phone, post photos to social media, or stream films without massive data loads. Lenna’s image was used for decades in papers, presentations, and textbooks across the fields of computer vision and image processing.

Despite the controversial origin, Lenna’s image became both a technological tool and a cultural phenomenon. It has also sparked long-standing debates about ethics, representation, and the appropriateness of sourcing test data from non-consensual or sexualised contexts. Yet her presence in computing history is undeniable: a face that launched a thousand file formats.