• Courtesy of the Pennebaker Family
• Bill Pennebaker and collaborators at IBM Research Center

Teaching online during the pandemic made Elizabeth Allen-Pennebaker think of her father — not just because the octogenarian shared her home in Burlington's Hill Section, near her office at Champlain College.

William Boone Pennebaker Jr. (October 23, 1935-September 8, 2021 ) came to mind because he helped develop the technology that allowed her to keep working when COVID-19 prevented in-class learning. An assistant professor in the college's Core division, she often told her dad, "It's because of you that I have a job."

Bill was an engineer with expertise in computer software science. At the IBM Thomas J. Watson Research Center in Yorktown Heights, N.Y., he helped develop a way to compress a photograph, enabling its efficient storage and transport while preserving the quality of the image. It was called a "joint photographic experts group," aka JPEG — which, in turn, was instrumental in the development of the MPEG, or moving picture experts group, used for videoconferencing.

Bill and company laid the groundwork for the innovation, said computer engineer Robert Moorhead, a former coworker of Bill's who is now a professor at Mississippi State University. "It's key," he said.

"I wouldn't call what Bill did revolutionary, but it was definitely evolutionary," Moorhead said, noting that developing JPEG technology was a collaborative endeavor among several groups.

In 2020, between Zoom classes, Allen-Pennebaker, 52, told her father: "'Hey, Dad. We use JPEGs all day long.'"

Bill and his late wife, Margaret Carlson Pennebaker, discovered Vermont in the mid-1960s. Before they were married, the two regularly drove from Westchester County, N.Y., in an unheated, red Volkswagen Beetle to ski at Mad River Glen.

"By the time you're done with that trip, you're either in love, or you can't stand each other and don't want to see each other again," Allen-Pennebaker said.

For Bill and Margaret, it was love. They got hitched in 1967 and settled in Carmel, N.Y., with dreams of moving to Vermont after retirement.

In his professional and personal pursuits, Bill was a problem solver — an engineer, inventor and builder who was deeply focused on his projects.

• Courtesy of the Pennebaker Family
• Bill with daughters Elizabeth and Patty riding an electric bicycle he built

"Bill was literally the prototype classic engineer," Moorhead said. "He did things in an orderly fashion. He was accurate. He developed things. He thought things through. He was tenacious. Bill didn't talk about something unless he thought it was going to work."

While at IBM, he and colleague Joan Mitchell developed the algorithms for a JPEG technique known as "lossless compression," according to Moorhead. The method remains a gold standard in the field some 30 years after its development, he said, allowing medical images to retain their definition and quality. Moorhead likened the digital compression process to suctioning the air out of a plastic bag of blankets before storing it.

Bill was busy at home, too. The family farmhouse was no-frills when he and Margaret bought it, with an outhouse for a toilet and a pump in the kitchen sink. Bill rebuilt the stone foundation, plumbed the house and wired it for electricity, among other projects he undertook in the old building.

"Most people will renovate. My dad restores," said Allen-Pennebaker's younger sister, Patty Rutins, a web designer who lives in Sunderland.

She recalled one winter when Bill was hard at work on a secret project in his basement workshop. On Christmas Day, he surprised his girls with a hand-hewn dollhouse — a three-story Colonial with electricity, pipes and a shingled roof.

"It was the staple of our playroom forever," Rutins said.

That is, until 1993, when Bill wrapped up his 35-year career at IBM and he and Margaret moved to Vermont.

In retirement, Bill worked on restoring the couple's Vermont home. They purchased a late 18-century house in Maine and transported the dismantled structure, piece by labeled piece, to their land in Shaftsbury. Construction workers handled framing and most of the assembly, but Bill helped reconstruct and restore the house, and the couple did some hands-on finish work. Bill made built-in period cabinets with a contemporary twist: a hydraulic lift that moved the TV around.

• Courtesy of the Pennebaker Family
• Bill at Bromley Mountain

He also crafted beautiful pieces of miniature furniture that were exhibited at the Bennington Museum. At Margaret's encouragement, he ran for and won a seat on the Shaftsbury Selectboard. She died in 2006, the first of the six years he served.

While Bill held elected office, the State of Vermont directed the Town of Shaftsbury to close and cap its landfill, according to Wynn Metcalfe, who was chair of the selectboard at the time. Bill took it upon himself to handle the project, researching the best and safest methods to shut the landfill and working with the state to facilitate the closure. His work saved Shaftsbury tens of thousands of dollars, Metcalfe estimated.

"It was a big deal, a huge deal," Metcalfe said. "The scientist came out in him, and he had the time and wanted to do it. And he did."

Bill worked on other inventions outside of IBM. He and a friend designed an early version of the electric bicycle that was powered by a car battery; the harder the rider pedaled, the more power the battery supplied.

"My father knew that all these modern e-bikes were derived from the work that he had done," Allen-Pennebaker said.

When he could no longer live alone, in 2015, Bill moved in with his oldest daughter. "My father was so wonderful, we duked it out over who was lucky enough to get him," Allen-Pennebaker recalled. "And I won."

He died at home on September 8, 2021, of progressive supranuclear palsy, at the age of 85.