The December 2022 issue of IEEE Spectrum is here!

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iCandy: Tech for the Hands, Eyes, and Body

Touch and see what isn’t really there

1 min read

Photo: Xinhua/eyevine/Redux
This gargantuan bucket is part of Taiyuan Heavy Industry Co.’s WK-75, the largest mining excavator in the world. The shovel, which can move 75 cubic meters of earth with a single scoop, can be used to dig up to 12 000 metric tons of coal per hour. But there is no concern that such heavy loads may cause the attached vehicle to tip over: The excavator is longer than a basketball court and weighs 2000 metric tons.

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From WinZips to Cat GIFs, Jacob Ziv’s Algorithms Have Powered Decades of Compression

The lossless-compression pioneer received the 2021 IEEE Medal of Honor

11 min read
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Photo of Jacob Ziv
Photo: Rami Shlush
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Lossless data compression seems a bit like a magic trick. Its cousin, lossy compression, is easier to comprehend. Lossy algorithms are used to get music into the popular MP3 format and turn a digital image into a standard JPEG file. They do this by selectively removing bits, taking what scientists know about the way we see and hear to determine which bits we'd least miss. But no one can make the case that the resulting file is a perfect replica of the original.

Not so with lossless data compression. Bits do disappear, making the data file dramatically smaller and thus easier to store and transmit. The important difference is that the bits reappear on command. It's as if the bits are rabbits in a magician's act, disappearing and then reappearing from inside a hat at the wave of a wand.

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