Russell Kirsch, a computer scientist known for scanning the first digital image, has died after a nearly two-decade long journey with FTD.

Considered the inventor of the digital pixel, Kirsch utilized the country’s first programmable computer, the Standards Electronic Automatic Computer, to scan the world’s first digital photograph in 1957. That image, a black and white snapshot of his newborn son, was later ranked by Life magazine among the “100 photographs that changed the world,” and became the foundation for technologies including satellite images, CT scans, bar codes and digital photography.

Kirsch was diagnosed with FTD around 2003, a journey his family has shared in the past. He died at age 91 at his home in Oregon, his son Walden, the subject of his father’s historic photograph, told the Washington Post.

“Dad was an eminent guy, and it’s sad to see that change,” Walden told Oregon Live in 2018. “He was brilliant, curious, verbal, questioning, a great teacher, mathematician, scientist and father.”

The Post recently ran a detailed obituary to commemorate Kirsch’s life and work, which you can read here.