Google open-sources data compression code for faster downloads

Google has made available online a new data compression code that it said can speed up downloads from the Internet —and benefit mobile Internet users.

 

Software engineer Lode Vandevenne said the algorithm, dubbed “Zopfli,” is an open-sourced general purpose data compression library named after a Swiss bread recipe.

 

“The smaller compressed size allows for better space utilization, faster data transmission, and lower web page load latencies. Furthermore, the smaller compressed size has additional benefits in mobile use, such as lower data transfer fees and reduced battery use,” Vandevenne said in a blog post.

 

Vandevenne said the new compression technique makes the compression much slower, but will not affect the decompression speed.

 

As a result, Zopfli’s compressed files are three to eight percent smaller compared to the present zlib at maximum compression.

 

“(W)e believe that Zopfli represents the state of the art in Deflate-compatible compression. Zopfli is written in C for portability. It is a compression-only library; existing software can decompress the data. Zopfli is bit-stream compatible with compression used in gzip, Zip, PNG, HTTP requests, and others,” Vandevenne said.

 

But Zopfli may take more time to compress files and may need two to three times more CPU time than zlib at maximum quality.

 

Thus, Vandevenne said Zopfli is best suited for applications where data is compressed once and sent over a network many times, such as static content for the web.

 

Open-sourcing

 

“By open sourcing Zopfli, thus allowing webmasters to better optimize the size of frequently accessed static content, we hope to make the Internet a bit faster for all of us,” Vandevenne added.

 

A separate article on PC World said Google and other services had been looking for ways to boost compression.

 

It said that in 2009, Google acquired data compression technology firm On2, while browser maker Opera has been refining compression functions. — TJD, GMA News