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ReCAPTCHA如何运作？

[英]How does ReCAPTCHA work?

原文 2009-09-16 21:52:44 0 2 security/ captcha/ recaptcha/ spam-prevention

My reading of this article suggests that a benefit of ReCAPTCHA is that it can have humans verify words not recognised in the OCR/digitization of books. 我对这篇文章的阅读表明，ReCAPTCHA的一个好处是它可以让人类验证OCR /书籍数字化中无法识别的单词。 It does this by using these words in "Are you human?" 它通过在“你是人吗？”中使用这些词来做到这一点。 tests. 试验。 So ReCAPTCHA kills two birds with one stone. 所以ReCAPTCHA一石二鸟。 Great! 大！

But I dont get it. 但我不明白。 If the word can't be recognised by the digitization process then what is the input entered, by the supposed human being, verified against? 如果数字化过程无法识别这个词，那么被假定的人输入的输入是什么？ How does this work? 这是如何运作的？

2 个解决方案

It shows two words. 它显示了两个词。 One of them the computer already knows, the other, it doesn't. 其中一台计算机已经知道，另一台则没有。 It assumes that if you get the known one right, that you must know the other. 它假定如果你知道正确的那个，你必须知道另一个。

You don't know which of the two is already known so you, theoretically can't trick it. 你不知道这两个中哪一个已经知道所以你理论上不能欺骗它。 Additionally, it will replay a word with multiple people to get independent confirmation before sending it back to the source (newspaper company, book scanning group) as a valid answer. 此外，它还会向多个人重播一个单词以获得独立确认，然后再将其作为有效答案发送回源（报纸公司，图书扫描组）。

But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? 但如果计算机无法读取这样的验证码，系统如何知道拼图的正确答案？ Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. 方法如下：OCR无法正确读取的每个新单词都会与另一个已知答案的单词一起提供给用户。 The user is then asked to read both words. 然后要求用户阅读这两个单词。 If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. 如果他们解决了已知答案的系统，系统会认为他们的答案对新答案是正确的。 The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct. 然后，系统将新图像提供给许多其他人，以更高的置信度确定原始答案是否正确。

http://recaptcha.net/learnmore.html http://recaptcha.net/learnmore.html

Quoted from LEARN HOW reCAPTCHA WORKS 引用来自学习如何工作

But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? 但如果计算机无法读取这样的验证码，系统如何知道拼图的正确答案？ Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. 方法如下：OCR无法正确读取的每个新单词都会与另一个已知答案的单词一起提供给用户。 The user is then asked to read both words. 然后要求用户阅读这两个单词。 If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. 如果他们解决了已知答案的系统，系统会认为他们的答案对新答案是正确的。 The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct. 然后，系统将新图像提供给许多其他人，以更高的置信度确定原始答案是否正确。