Signal Processing

In September 1992, a committee called the Joint Photographic Experts Group published a standard that would fundamentally change how humanity stores and shares images. The JPEG format, based on the discrete cosine transform (DCT), made digital photography practical by reducing file sizes by a factor of 10 while maintaining acceptable visual quality. Three decades later, JPEG remains the most widely used image format in the world, with billions of images created daily. ...

A 4K video at 60 frames per second contains roughly 1,423 megabits of raw data every second—enough to fill a typical home internet connection 14 times over. Yet streaming platforms deliver that same content at 15-25 megabits per second, and you barely notice the difference. This 50-100x reduction isn’t magic. It’s mathematics applied with ruthless efficiency. The techniques that make this possible have evolved over three decades, from the H.261 videoconferencing standard in 1988 to today’s AV1 and H.266/VVC codecs. Each generation has squeezed out additional compression while maintaining perceptual quality, but the fundamental principles remain unchanged: exploit redundancy in space and time, discard information humans can’t perceive, and encode the remainder as efficiently as possible. ...