Image Courtesy: Apple
What began as a simple workaround for a display limitation on an early Macintosh computer eventually turned into one of the most widely used image editing tools. In 1987, Thomas Knoll, then a PhD student, wrote a small program to simulate grayscale on a black and white screen, laying the groundwork for what would become Photoshop.
The initial tool, called “Display,” was created to support Knoll’s computer vision research. At the time, the Macintosh Plus could only show black and white images, making detailed visual work difficult. The project evolved when his brother, John Knoll, recognized its potential for digital image processing.
John Knoll, who worked at Industrial Light and Magic, saw how the software could be used to manipulate images digitally, an emerging concept in the late 1980s. He encouraged his brother to expand the program into a more comprehensive tool by combining multiple image processing utilities into a single application. This shift introduced the integrated workflow that remains central to Photoshop today.
Thoman Knoll. Credit: Computer History Museum
One of the early technical challenges involved differences in how images appeared across computer monitors. To address this, Thomas Knoll developed the Levels adjustment feature, drawing from his experience with traditional darkroom photography. This feature allowed users to control brightness and contrast digitally, translating analog techniques into software.
The project was initially named ImagePro before being renamed Photoshop. Early versions were shared with several technology companies, many of which declined to pursue it. Adobe ultimately recognized its potential and acquired distribution rights. Photoshop 1.0 was released in 1990 exclusively for Macintosh systems.
At launch, the software targeted professional users such as graphic designers and publishers. It included tools like the Lasso and Magic Wand, which significantly reduced the time required for image editing tasks. However, its early adoption was limited by the lack of consumer digital cameras and affordable printing options.
John Knoll. Credit: Computer History Museum
The software’s growth accelerated in the 1990s with the expansion of the internet and the development of digital photography. As image creation and sharing became more common, Photoshop provided the tools needed to process and refine visual content.
Over time, Photoshop expanded across platforms and use cases, influencing industries including photography, publishing, film, and web design. The original source code has since been preserved by the Computer History Museum, reflecting its role in the evolution of digital media tools.