For years, Google has been trying to reduce how much space images take up on the web. Most of those efforts have been based around its proprietary (and largely ignored by non-Google entities) WebP format, but a new project out of the company’s research and open source divisions could help make JPEG images — one of the most common image formats on the planet — up to 35 per cent smaller, while retaining their quality.
The project is an image encoder called Guetzli (which is Swiss German for cookie; the project was born out of Google Research's Zurich office). In addition to making image files that are smaller, Guetzli is also focused on creating images that look better than other compressed images, too.
Check out these comparisons Google offered up to show Guetzli compared to an uncompressed image or an image compressed using the common libjpeg encoder.
The first image is uncompressed. The second is compressed with libjpeg. The third image was compressed with Guetzli and has fewer digital artifacts, even though its file size is smaller than the libjepeg file. (Image: Google)
In fact, Google claims that its research shows that even when image file sizes are the same (meaning the libjpeg files are encoded in a higher quality setting, resulting in larger file sizes), human raters like the Guetzli images better.
Again, the first image is uncompressed. The second image is encoded with libjpeg and the third image uses Guetzli.
The more important thing, however, as Ars Technica notes, is that Guetzli works with the web browsers and file formats we already have. Other attempts at making images smaller have all relied on building new image formats that never get broad enough support to actually take off. The beauty of this project is that it creates JPEG images the world already uses.
Google has made the Guetzli encoder open source, and it's available on Github for anyone to integrate into their own projects or to use on their own. That's a big deal because right now, many web-based image programs (and even stand alone image processing apps) use the libjpeg encoder because it is free and tends to do a good enough job. If Guetzli does work as well as Google claims, this could potentially be a solid libjpeg replacement for web developers, designers or photographers. It will also be good for regular web users because photos and images will take up less space.