A long time ago, when we were using 3.5” floppy disks with a capacity of 1.44 MB, compression was a very serious IT problem. Hard drives were also small, and a 13 GB hard drive was the dream. Today we have much larger storages, but we generate and store much more data. This is why Google is working on a new JPEG compression algorithm that is 35% more efficient than the current solutions.

You probably wonder why we need more efficient compression methods. This may not be visible, but all web sites use compression mechanisms. However, this is not used in order to save space on servers. The whole thing is to speed up the loading of web pages and to reduce the access time to content. It is true that today we have very fast internet connections, computers and smartphones. However, the fast loading of web pages is also achieved by the image compression algorithms.

The new algorithm developed by Google is called Guetzli.

Interestingly, this is an open-source solution, so anyone interested can implement the Guetzli algorithm in their application. However, it is not a salvation for all of our problems with large jpeg files (most often photos). The Guetzli algorithm gives very satisfactory results, but it requires a lot of computing power and RAM. Compression of a resolution of 1 megapixel requires approximately 300 MB of RAM. Therefore, it will not be possible to use it in smartphones and digital cameras. Implementation of Guetzli in graphical applications such as GIMP and Photoshop also seems to be pointless. However, the different story are cloud servers with photos.

Compression example
Fragment (20×24 pixels) of image compressed with different methods: no compression (left), libjpeg (center) and Guetzli (right).

People prefer images compressed by the Guetzli algorithm.

Google conducted a fairly simple experiment with 31 different photographs. The images were compressed using the new method and the usual libjpeg codec, with both files being kept in a similar file size. It turned out that in 75% of cases people preferred Guetzla photos because of higher quality. This demonstrates that the focus of the algorithm on the choice of colour quantization gives a satisfactory effect to the human eye. All indications are that Google will adopt a new compression algorithm on large-scale. We should be happy with that because we will save our mobile data packets. Photos compressed using the Guetzli algorithm are 100% compatible with all web browsers and can be viewed on any smartphone. You do not even need to update anything. Just wait until Google launches Guetzli compression on a large scale and treat it with the graphics held in Google Drive. I bet that also Facebook and other, where we collect a lot of photos, will interest in this subject in the near future.

Source: Google blog