How Google reCAPTCHA Buy Buoys Google Book Search

By Clint Boulton  |  Posted 2009-09-16 Print this article Print

Google today bought reCAPTCHA, a company that provides CAPTCHAs to shield more than 100,000 Websites from spam and fraud.

But Google isn't just trying to fend off spam, it's buying the startup to improve book scanning for its Google Book Search project.

CAPTCHAs, short for a "Completely Automated Public Turing test to tell Computers and Humans Apart" are those quixotic codes you have to enter into Websites to let them know you are human and not some grubby spamming machine, which has trouble deciphering the funky text and words the CAPTCHAS put in front of them as passwords to enter.

ReCAPTCHA Founder Luis von Ahn and others actually coined the CAPTCHA term at Carnegie Mellon University in 2000. Von Ahn, a computer science professor at the university, went on to create reCAPTCHA in 2008.

We use CAPTCHAs at eWEEK as a buffer between our Web pages and readers who want to leave comments:

Captcha for google buy.png

Yet Google targeted reCAPTCHA for another reason. The words in many of reCAPTCHA's CAPTCHAS (say that 10 times fast!) come from scanned archival newspapers and old books, in which the ink has degraded over time.

While computers find these words hard to recognize, we users keep typing them in as a CAPTCHA, crowdsourcing away as we teach computers to read the scanned text. ReCAPTCHA actually invites users to do this on its Website:


Because this technology improves the Optical Character Recognition (OCR) process of converting scanned images into plain text, the technology can boost text scanning projects such as Google Books and Google News Archive Search. Google Product Manager Will Cathcart and von Ahn note:

Having the text version of documents is important because plain text can be searched, easily rendered on mobile devices and displayed to visually impaired users. So we'll be applying the technology within Google not only to increase fraud and spam protection for Google products but also to improve our books and newspaper scanning process.

ReadWriteWeb's Frederic Lardinois nails it when he notes:

Google currently makes over 1 million out-of-copyright books available for download through Google Books and one of the main arguments against these books has been the fact that these texts are not edited and include a lot of OCR errors. With reCAPTCHA, Google could potentially bring the error rate down dramatically and make Google Books even more useful.

Of course, this endeavor may be for naught if Google Book Search does not bank the district court's approval Oct. 7, or pass muster with the Justice Department.

If this is the case, reCAPTCHA will remain a fine buy for Google's spam-fighting effort, but as I've said before, I believe the Google Book Search will be blessed, albeit with some modifications.

More coverage on this on Google's latest buy on TechMeme here. |

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