- Person
- Jacob Ziv
- Lived
- 1931–2023
- Field
- Information theory
- From
- Israeli
The story
Jacob Ziv was born in 1931 in Tiberias, in British-ruled Palestine, to Jewish parents who had emigrated from Russia. After serving as a teenage soldier and radar technician in the 1948 war, he studied electrical engineering at the Technion in Haifa and earned a doctorate at MIT in 1962. He became a leading figure in information theory, the mathematical science of communication.
In the 1970s, at the Technion, Ziv teamed up with the computer scientist Abraham Lempel. They wanted a method of lossless compression, one that shrinks data and restores it exactly, that would work on any kind of data without knowing its statistics in advance, and still come close to the theoretical limit. In 1977 they published A Universal Algorithm for Sequential Data Compression, the method known as LZ77. It reads data once and, whenever it finds a stretch that has appeared before, replaces it with a short pointer to the earlier copy. A second method, LZ78, followed in 1978, building a dictionary of phrases as it goes. The older standard method needed two passes and had to store a codebook; theirs needed neither.
The Lempel-Ziv methods became the foundation of everyday computing. LZ78, through a variant called LZW, powered the Unix compress program and the GIF image format. LZ77 sits at the heart of the Deflate method used in ZIP archives, the gzip tool and PNG images. The Technion notes that the algorithm underlies formats such as PNG, GIF, ZIP and TIFF and played a major role in PDF and MP3.
In 2021 Ziv received the IEEE Medal of Honor, the first Israeli scientist to do so, for fundamental contributions to information theory and data compression technology. Because the methods were published openly in scientific journals, programmers around the world could build them into software freely, and they remain at the core of file and image formats decades later. Ziv died in 2023, aged 91, a few weeks after Lempel.
Why it matters
Lempel-Ziv compression makes files smaller and web pages faster, saving storage, bandwidth and energy for billions of people every day.
About Jacob Ziv
Israeli engineer who, with Abraham Lempel, invented the Lempel-Ziv compression methods inside ZIP files, PNG and GIF images and much more, making data cheaper to store and faster to send.
Sources
- From WinZips to Cat GIFs, Jacob Ziv’s Algorithms Have Powered Decades of Compression IEEE Spectrum
- Dist. Prof. Jacob Ziv 1931–2023 Technion
- Jacob Ziv Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.