Ars Technica

Inventor says Google is patenting work he put in the public domain

Enlarge / Meet inventor Jarek Duda.
Jarek Duda











ANS: Better, faster compression

Enlarge / Facebook has created a compression library based on ANS.











Google is patenting the use of ANS for video compression










The patent system makes it hard to give your idea away

US Patent and Trademark Office in Alexandria, Virginia.

ANS functions as a faster replacement for arithmetic coding schemes. Those schemes were invented in the 1970s and quickly became encumbered by patents, limiting their use during the early years. Duda told Ars that he is determined not to have that happen to ANS. He hoped that by publishing his work and not seeking his own patents, he could preclude anyone else from patenting the technique and leave it free for anyone to use.

The patent system may ultimately give Jarek Duda what he wants: patent offices in the US and Europe may reject Google's patent application, keeping ANS free for anyone to use. But if so, it will be thanks to months of hard work on his part.

In theory, the mere act of publishing an invention without applying for a patent should be enough to put it in the public domain. Patent examiners are supposed to search for prior art before granting a patent—and prior art can be found in any published work. So if an invention has been previously disclosed to the public, an examiner is supposed to find that disclosure and use it to reject a patent application.

The problem is that examiners aren't omniscient. They don't have the tools to search every document that has ever been published. And even if they did, they wouldn't necessarily be able to find publications that describe the same invention in different words.

Patent examiners also have limited time. In the United States, a typical examiner is supposed to devote a total of 19 hours to all phases of the examination process. That's not much time to understand a complex technology and then try to search every document ever published for references to it.

In practice, US examiners often lean heavily on the patent database itself to find prior art. Patents are in a format that's convenient for patent examiners, and they're already grouped by technology type, making it easy to find relevant patents. So if you apply for a patent, the patent office will likely prevent anyone from claiming something too similar to your invention. But if, like Duda, you choose not to get a patent on your invention, the patent office may not realize that you previously disclosed the invention, so they might grant a patent to someone else.

The European patent system offers a mechanism for third parties like Duda to supply information during the examination process. Duda took advantage of that process to submit a letter last October pointing out the similarities of his own prior work to Google's patent. The US Patent Office recently made a similar mechanism available. But this process puts the onus on inventors to monitor patent applications and object to efforts to patent their own work.

"There are many people like me who would just like their work to be used by others without restriction," Duda told Ars. "The patent office usually just checks not even the literature. They just check patents. If something was not written in patents, it's unlikely they'll find it."

"If the patent is granted, it's very difficult to get rid of it," Duda said. "They can sue you for millions of dollars, and to get rid of an existing patent, it costs hundreds of thousands of dollars."

Google has been an advocate for open video

To be fair to Google, the search giant has often been an advocate of keeping video standards free of patent encumbrances. Back in 2011, Google said it would drop support for the patent-encumbered H.264 codec from Chrome, allying itself with the open-standards advocates at Firefox. Google pushed its own VP8 codec as a more open alternative. More recently, Google promoted its royalty-free VP9 codec and has declared its support for the royalty-free AV1 format.

Google argues that nothing has changed—it's still committed to video formats being open and royalty-free.

So then why is Google trying to patent ANS-based video in the first place? Google declined to talk to us about this, so we can only speculate. But one likely reason is to provide leverage against other companies with large patent portfolios of their own. The boundaries of patents are never perfectly clear, so even if Google tries to exclusively use open, royalty-free codecs, it always has to worry about someone getting a patent that applies to Google's own video techniques.

Google's pursuit of the ANS patent might also be a simple act of bureaucratic absent-mindedness. Google has a large staff of patent lawyers, and their job is to get as many patents as possible. Steeped in patenting culture, it might simply not have occurred to them that someone like Duda might make a deliberate choice not to patent his invention—and might be offended by Google's attempt to do so.

In any event, Duda doesn't trust the search giant's intentions. He points to the recent lawsuit between Waymo, Google's self-driving car company, and Uber. That case was primarily about the alleged theft of trade secrets, but Waymo also included some patent claims in the lawsuit (the patent claims were dropped after a few months). In Duda's view, that belies claims that Google would only use patents in retaliation for others who sue Google for patent infringement.

"If they would guarantee that this patent will become open, maybe offered me a coauthorship, I would have no problem," Duda told Ars. "But nothing like this has happened."

Listing image by Photograph by Adrian Libotean