I think I need a bigger hammer...
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I think it's a communication issue here. The original poster seems to be researching ways to break captcha (hopefully for non-malicious purposes). Some people have already done some research into that area. Example : http://www.cs.sfu.ca/~mori/research/gimpy/[^]
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)I know it can be done. There are implementations of CAPTCHA that are far weaker than others. I just don't help people try to break something that other people use to secure their sites with. If he can type "CAPTCHA OCR" into Google, he'll get far more useful information, but he has to do that himself. The fact that he's asking for help at such a general level tells me that he knows nothing of OCR in the first place, let alone how to even start an advanced implementation of OCR that can crack one of these things. Plus, from what I've seen around the web on the subject, the implementation of his OCR would have to be pretty nearly custom made to defeat the features of the CAPTCHA type he's looking at. Things like lines throught the text, characters offset from each other, wavy text, different colors, overlapping characters, background blends, ..., would all have to be handled on a case-by-case basis. You could implement some analysis functionality for some of these things, but there's no way for the code to be absolutely sure of what it's dealing with without some outside help.
Dave Kreskowiak Microsoft MVP - Visual Basic
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I know it can be done. There are implementations of CAPTCHA that are far weaker than others. I just don't help people try to break something that other people use to secure their sites with. If he can type "CAPTCHA OCR" into Google, he'll get far more useful information, but he has to do that himself. The fact that he's asking for help at such a general level tells me that he knows nothing of OCR in the first place, let alone how to even start an advanced implementation of OCR that can crack one of these things. Plus, from what I've seen around the web on the subject, the implementation of his OCR would have to be pretty nearly custom made to defeat the features of the CAPTCHA type he's looking at. Things like lines throught the text, characters offset from each other, wavy text, different colors, overlapping characters, background blends, ..., would all have to be handled on a case-by-case basis. You could implement some analysis functionality for some of these things, but there's no way for the code to be absolutely sure of what it's dealing with without some outside help.
Dave Kreskowiak Microsoft MVP - Visual Basic
Ah okay. I had assumed that you posted it in the Hall of Shame because of how he couldn't properly understand your replies to him. But now, I am confused. What's Hall-of-Shame-ish about that thread? It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
Ah okay. I had assumed that you posted it in the Hall of Shame because of how he couldn't properly understand your replies to him. But now, I am confused. What's Hall-of-Shame-ish about that thread? It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)Nishant Sivakumar wrote:
It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :)
Time was, a person starting out on a project where they possessed no knowledge of the area in question would... you know, go to a library and research it. Now we have The Internet, and i've gotta say, researching things like this has become a much easier task... yet, time and time again, we see people asking the most basic questions, questions that would be answered in minutes by a quick search on Google. I tend to assume then, that they've already used Google, and simply couldn't comprehend any of the answers. Being the humble sort of person that i am, i realize that my answer would likely do no better, and prudently withhold it. :rolleyes: What strikes me as odd about this particular post though, is that he seems to understand roughly what he'll need to do: prior to his question, he lists three steps required to perform the task (i've no idea if they're accurate or not, but it's a start...) So given that, i don't understand why he doesn't (say) look for a noise reduction algorithm, an OCR library, a string-handling tutorial for whatever language he plans to work in, etc. Again, all of these things are just about as common as the tumbleweeds piling up around my neighborhood. Donno whether that really qualifies it as a WTF though; it seems to be closer to the norm here some days. :sigh:
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It appears that everybody is under the impression that I approve of the documentation. You probably also blame Ken Burns for supporting slavery.
--Raymond Chen on MSDN
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I think it's a communication issue here. The original poster seems to be researching ways to break captcha (hopefully for non-malicious purposes). Some people have already done some research into that area. Example : http://www.cs.sfu.ca/~mori/research/gimpy/[^]
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
Nishant Sivakumar wrote:
It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :)
Time was, a person starting out on a project where they possessed no knowledge of the area in question would... you know, go to a library and research it. Now we have The Internet, and i've gotta say, researching things like this has become a much easier task... yet, time and time again, we see people asking the most basic questions, questions that would be answered in minutes by a quick search on Google. I tend to assume then, that they've already used Google, and simply couldn't comprehend any of the answers. Being the humble sort of person that i am, i realize that my answer would likely do no better, and prudently withhold it. :rolleyes: What strikes me as odd about this particular post though, is that he seems to understand roughly what he'll need to do: prior to his question, he lists three steps required to perform the task (i've no idea if they're accurate or not, but it's a start...) So given that, i don't understand why he doesn't (say) look for a noise reduction algorithm, an OCR library, a string-handling tutorial for whatever language he plans to work in, etc. Again, all of these things are just about as common as the tumbleweeds piling up around my neighborhood. Donno whether that really qualifies it as a WTF though; it seems to be closer to the norm here some days. :sigh:
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It appears that everybody is under the impression that I approve of the documentation. You probably also blame Ken Burns for supporting slavery.
--Raymond Chen on MSDN
I took his replies as "I know I can't do that, but how do I do it?". :wtf: It may seem like he's researching methods to do this for "educational purposes only", but I just don't take that kind of chance when security is involved. How do I know that he's not trying to build something to, say, scarf up event tickets on TicketMaster and scalp them? :wtf: There are sites out there dedicated to the research of the strength of various CAPTCHA methods. Any 5 second Google search will tell you that. It just amazes me that if a search that simple eludes someone, what possible hope does he have of even understanding the concepts behind an advanced OCR algorithm let alone comming up with the search terms to use in Google? :wtf: But, you're right, it's probably not the best WTF material. More like a "what was he thinking?" maybe... :->
Dave Kreskowiak Microsoft MVP - Visual Basic
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I took his replies as "I know I can't do that, but how do I do it?". :wtf: It may seem like he's researching methods to do this for "educational purposes only", but I just don't take that kind of chance when security is involved. How do I know that he's not trying to build something to, say, scarf up event tickets on TicketMaster and scalp them? :wtf: There are sites out there dedicated to the research of the strength of various CAPTCHA methods. Any 5 second Google search will tell you that. It just amazes me that if a search that simple eludes someone, what possible hope does he have of even understanding the concepts behind an advanced OCR algorithm let alone comming up with the search terms to use in Google? :wtf: But, you're right, it's probably not the best WTF material. More like a "what was he thinking?" maybe... :->
Dave Kreskowiak Microsoft MVP - Visual Basic
Dave Kreskowiak wrote:
More like a "what was he thinking?"
There's a new forum idea :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
Well, maybe what the problem is... he took some random string and made a CAPTCHA image of it and now he's trying to compare the user's response with his string, but didn't store the string so he is trying to un-CAPTCHA it to perform the compare? :-D
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Dave Kreskowiak wrote:
More like a "what was he thinking?"
There's a new forum idea :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)I think we already have it. It's called VB.NET Forum... :rolleyes:
Dave Kreskowiak Microsoft MVP - Visual Basic
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Well, maybe what the problem is... he took some random string and made a CAPTCHA image of it and now he's trying to compare the user's response with his string, but didn't store the string so he is trying to un-CAPTCHA it to perform the compare? :-D
Sadly, this happens all too often!
Dave Kreskowiak Microsoft MVP - Visual Basic
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next article I'll write. I think I'll develop a CCaptchaToOCR class. Publication date set for April 1. :)
Chris Meech I am Canadian. [heard in a local bar] I agree with you that my argument is useless. [Red Stateler] Hey, I am part of a special bread, we are called smart people [Captain See Sharp] The zen of the soapbox is hard to attain...[Jörgen Sigvardsson] I wish I could remember what it was like to only have a short term memory.[David Kentley]
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next article I'll write. I think I'll develop a CCaptchaToOCR class. Publication date set for April 1. :)
Chris Meech I am Canadian. [heard in a local bar] I agree with you that my argument is useless. [Red Stateler] Hey, I am part of a special bread, we are called smart people [Captain See Sharp] The zen of the soapbox is hard to attain...[Jörgen Sigvardsson] I wish I could remember what it was like to only have a short term memory.[David Kentley]
...inhale deeply...hold breath... :-D
Dave Kreskowiak Microsoft MVP - Visual Basic
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Dave, you've made my day. That's the funniest shit I've seen in quite sometime. I can imagine how you must have felt :laugh:
Nobody can give you wiser advice than yourself. - Cicero ப்ரம்மா
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Ah okay. I had assumed that you posted it in the Hall of Shame because of how he couldn't properly understand your replies to him. But now, I am confused. What's Hall-of-Shame-ish about that thread? It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)What, you mean instead of starting with a string reversing function?
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Nishant Sivakumar wrote:
It seems to be a newbie attempting to do something he has no clue about - much like those first time C++ programmers trying to write an advanced TCP server as their first project :)
Time was, a person starting out on a project where they possessed no knowledge of the area in question would... you know, go to a library and research it. Now we have The Internet, and i've gotta say, researching things like this has become a much easier task... yet, time and time again, we see people asking the most basic questions, questions that would be answered in minutes by a quick search on Google. I tend to assume then, that they've already used Google, and simply couldn't comprehend any of the answers. Being the humble sort of person that i am, i realize that my answer would likely do no better, and prudently withhold it. :rolleyes: What strikes me as odd about this particular post though, is that he seems to understand roughly what he'll need to do: prior to his question, he lists three steps required to perform the task (i've no idea if they're accurate or not, but it's a start...) So given that, i don't understand why he doesn't (say) look for a noise reduction algorithm, an OCR library, a string-handling tutorial for whatever language he plans to work in, etc. Again, all of these things are just about as common as the tumbleweeds piling up around my neighborhood. Donno whether that really qualifies it as a WTF though; it seems to be closer to the norm here some days. :sigh:
----
It appears that everybody is under the impression that I approve of the documentation. You probably also blame Ken Burns for supporting slavery.
--Raymond Chen on MSDN
Shog9 wrote:
it seems to be closer to the norm here some days
yup. in a way it's nice to know that it's not just the stereotypical lazy American kid who wants everything handed to him without having to spark any neurons beyond those required to pout and say "me want!" - there are spoiled lazy kids everywhere!
image processing toolkits | batch image processing | blogging
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Or maybe he's trying to test his CAPTCHA-ing algorithm?
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Or maybe he's trying to test his CAPTCHA-ing algorithm?
Somehow, I seriously doubt it.
Dave Kreskowiak Microsoft MVP - Visual Basic
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Shog9 wrote:
it seems to be closer to the norm here some days
yup. in a way it's nice to know that it's not just the stereotypical lazy American kid who wants everything handed to him without having to spark any neurons beyond those required to pout and say "me want!" - there are spoiled lazy kids everywhere!
image processing toolkits | batch image processing | blogging