How could I convert a image with letters to text?

Question

I need to find letters in a image. I need a help to write an algorithm to decode the image.

I got the image an there is converted in a ByteArrayOutputStream but I don´t know what I do with it.

There is my java code:

URL url = new URL(urlImg);
WebClient webClient = new WebClient(BrowserVersion.getDefault());
WebRequest reqImg = new WebRequest(url);
reqImg.setHttpMethod(HttpMethod.GET);
InputStream imgStream = webClient.getPage(reqImg).getWebResponse().getContentAsStream();
BufferedImage img = ImageIO.read(imgStream);
ByteArrayOutputStream out = new ByteArrayOutputStream();
ImageIO.write(img, "png", out);

Dependencies: net.sourceforge.htmlunit htmlunit 2.15

JDK 1.6.0_43

Yes, I need it to validate an application. This a question about java. — bpedroso, Jul 29 '14 at 19:22
This is the point of captcha, so you can't convert it to text. — Rocky Pulley, Jul 29 '14 at 16:16
On my web application, the best way to do it was to show the image to the client. — bpedroso, Sep 03 '14 at 21:25

Alex Podworny · Accepted Answer · 2014-07-29T16:36:29.140

11

http://scraping.pro/example-captcha-solver-java/

I noticed that you're using Java, this is a way to do it in Java. Decoding Captchas is very possible, assuming the captcha is not very secure. This is exactly why captchas are always getting more complex - people can break them.

Edit If you aren't hard set on Java and don't want to use a paid service, you could use this tutorial with Python: http://www.boyter.org/decoding-captchas/

-By the way- Decoding Captchas is not always unethical. Sometimes it is required or makes life much easier. For example a company I'm working with will not disable the Captcha on their sites for automated tests that I've made. If I wanted to run my automated tests, I'd have to bypass the Captcha. Granted that also means other people can also bypass the Captcha if they really wanted to, but the company apparently doesn't care and wants easy to read, traditional Captchas.

edited Jul 29 '14 at 16:36

answered Jul 29 '14 at 16:20

Alex Podworny

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But, he uses deathbycaptcha. This is a paid service. I think that anyone have already write an algorithm to decode a image. This is not my expertise, but I´m trying here. if I get success, I ll post the answer here. Thanks. – bpedroso Jul 29 '14 at 16:26
@bpedroso Updated answer with alternate Python method, which does not require a paid service. – Alex Podworny Jul 29 '14 at 16:39
3

One reason to use a paid service: If you do it yourself, your code will likely stop working next month as soon as someone comes up with a new captcha scheme. If you pay someone to do it, they will crack the new scheme, and your code will quickly start working again at no extra effort on your part. Whether that's worth paying for is of course an economic question that depends primarily on your particular use case, not a technical question. – abarnert Aug 12 '14 at 07:09

How could I convert a image with letters to text?

1 Answers1