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  4. How to get data from image

How to get data from image

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  • J JanapatiBalu

    Hi, How can we get data or characters which is present on image.Actually i have captcha images in .JPEG extension and from that images i have to remove noise, extract the characters and then i have to convert the extracted characters in to string.So please give some idea how to proceed further.

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    Dave Kreskowiak
    wrote on last edited by
    #2

    There's a reason why it's noisy and distorted. It's so that you CAN'T use automation to get those characters!

    Dave Kreskowiak Microsoft MVP - Visual Basic

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    • D Dave Kreskowiak

      There's a reason why it's noisy and distorted. It's so that you CAN'T use automation to get those characters!

      Dave Kreskowiak Microsoft MVP - Visual Basic

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      JanapatiBalu
      wrote on last edited by
      #3

      Hai Dave, The image is noisy because, the image is a captcha image as you know there will be noise in captcha image.I have captcha images with JPEG extension, i have to remove noise from captcha image and after that i have to extract characters from captcha image. please give reply it would be help full for me......... regards, Balu.

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      • J JanapatiBalu

        Hai Dave, The image is noisy because, the image is a captcha image as you know there will be noise in captcha image.I have captcha images with JPEG extension, i have to remove noise from captcha image and after that i have to extract characters from captcha image. please give reply it would be help full for me......... regards, Balu.

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        Dave Kreskowiak
        wrote on last edited by
        #4

        What did I just get done telling you?? You CAN'T DO THAT because CAPTCHA was designed specifically to defeat what you're trying to do!

        Dave Kreskowiak Microsoft MVP - Visual Basic

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        • D Dave Kreskowiak

          What did I just get done telling you?? You CAN'T DO THAT because CAPTCHA was designed specifically to defeat what you're trying to do!

          Dave Kreskowiak Microsoft MVP - Visual Basic

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          JanapatiBalu
          wrote on last edited by
          #5

          Dave i understood what u have suggested me. ok removing noise is difficult, but give some idea how can i extract data from captcha image.Give reply if u have idea about extracting data from image. Regards, Balu.

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          • J JanapatiBalu

            Dave i understood what u have suggested me. ok removing noise is difficult, but give some idea how can i extract data from captcha image.Give reply if u have idea about extracting data from image. Regards, Balu.

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            Dave Kreskowiak
            wrote on last edited by
            #6

            What part of "YOU CAN'T DO THAT" don't you understand? The text in those images is deliberatly wavy a filled with noise so that no OCR software can read it. You can't get the text in a CAPTCHA image because there's no technology out there that can read it! That's the whole point behind CAPTCHA!! It's a test to determine if a machine is trying to access a website or if its a human doing it. The machines will always fail this test because there's no way they can make out the text in the image.

            Dave Kreskowiak Microsoft MVP - Visual Basic

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            • J JanapatiBalu

              Dave i understood what u have suggested me. ok removing noise is difficult, but give some idea how can i extract data from captcha image.Give reply if u have idea about extracting data from image. Regards, Balu.

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              Craster
              wrote on last edited by
              #7

              No, you haven't understood. The whole purpose of captcha images is to ensure that it is a human that is viewing the image. They are specifically designed to make it impossible for any kind of automated tool to extract the data. So, not only is it as impossible as makes no difference, you also can't really have a good reason to be doing it - attempting to bypass security controls is a bad thing.

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              • D Dave Kreskowiak

                What part of "YOU CAN'T DO THAT" don't you understand? The text in those images is deliberatly wavy a filled with noise so that no OCR software can read it. You can't get the text in a CAPTCHA image because there's no technology out there that can read it! That's the whole point behind CAPTCHA!! It's a test to determine if a machine is trying to access a website or if its a human doing it. The machines will always fail this test because there's no way they can make out the text in the image.

                Dave Kreskowiak Microsoft MVP - Visual Basic

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                Maximilien
                wrote on last edited by
                #8

                Dave Kreskowiak wrote:

                You can't get the text in a CAPTCHA image because there's no technology out there that can read it!

                not yet at least.


                Maximilien Lincourt Your Head A Splode - Strong Bad

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                • J JanapatiBalu

                  Hi, How can we get data or characters which is present on image.Actually i have captcha images in .JPEG extension and from that images i have to remove noise, extract the characters and then i have to convert the extracted characters in to string.So please give some idea how to proceed further.

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                  Nish Nishant
                  wrote on last edited by
                  #9

                  This article may help :- http://www.cs.sfu.ca/~mori/research/gimpy/[^] It probably won't help you break more advanced captchas though.

                  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*)

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                  • J JanapatiBalu

                    Hi, How can we get data or characters which is present on image.Actually i have captcha images in .JPEG extension and from that images i have to remove noise, extract the characters and then i have to convert the extracted characters in to string.So please give some idea how to proceed further.

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                    Dan Neely
                    wrote on last edited by
                    #10

                    As Dave and Nish have said, CAPTCHAs are explicitly designed to defeat OCR. It may not be totally impossible, you're going to have to do a good amount of research to try and process them. Noone has written a CCaptchaOcrConverter class that you can just copy/paste into your application.

                    -- CleaKO The sad part about this instance is that none of the users ever said anything [about the problem]. Pete O`Hanlon Doesn't that just tell you everything you need to know about users?

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                    • D Dan Neely

                      As Dave and Nish have said, CAPTCHAs are explicitly designed to defeat OCR. It may not be totally impossible, you're going to have to do a good amount of research to try and process them. Noone has written a CCaptchaOcrConverter class that you can just copy/paste into your application.

                      -- CleaKO The sad part about this instance is that none of the users ever said anything [about the problem]. Pete O`Hanlon Doesn't that just tell you everything you need to know about users?

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                      Dan Neely
                      wrote on last edited by
                      #11

                      dan neely wrote:

                      It may not be totally impossible, you're going to have to do a good amount of research to try and process them.

                      PS IF you don't even know all the right questions to ask, you're probably not the right person to be doing the actual research either.

                      -- CleaKO The sad part about this instance is that none of the users ever said anything [about the problem]. Pete O`Hanlon Doesn't that just tell you everything you need to know about users?

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                      • D Dan Neely

                        dan neely wrote:

                        It may not be totally impossible, you're going to have to do a good amount of research to try and process them.

                        PS IF you don't even know all the right questions to ask, you're probably not the right person to be doing the actual research either.

                        -- CleaKO The sad part about this instance is that none of the users ever said anything [about the problem]. Pete O`Hanlon Doesn't that just tell you everything you need to know about users?

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                        Dave Kreskowiak
                        wrote on last edited by
                        #12

                        dan neely wrote:

                        IF you don't even know all the right questions to ask, you're probably not the right person to be doing the actual research either.

                        Bingo!

                        Dave Kreskowiak Microsoft MVP - Visual Basic

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                        • D Dave Kreskowiak

                          dan neely wrote:

                          IF you don't even know all the right questions to ask, you're probably not the right person to be doing the actual research either.

                          Bingo!

                          Dave Kreskowiak Microsoft MVP - Visual Basic

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                          Wayne Phipps
                          wrote on last edited by
                          #13

                          OMG, this thread has to be the funniest thing I've read for ages. It's brightend my day. Thanks guys!

                          Regards Wayne Phipps ____________ Time is the greatest teacher... unfortunately, it kills all of its students View my Blog

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                          • D Dave Kreskowiak

                            What part of "YOU CAN'T DO THAT" don't you understand? The text in those images is deliberatly wavy a filled with noise so that no OCR software can read it. You can't get the text in a CAPTCHA image because there's no technology out there that can read it! That's the whole point behind CAPTCHA!! It's a test to determine if a machine is trying to access a website or if its a human doing it. The machines will always fail this test because there's no way they can make out the text in the image.

                            Dave Kreskowiak Microsoft MVP - Visual Basic

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                            D Offline
                            DavidNohejl
                            wrote on last edited by
                            #14

                            Dave Kreskowiak wrote:

                            What part of "YOU CAN'T DO THAT" don't you understand?

                            I am sorry Dave, I am afraid can't do that. :rolleyes:


                            "Throughout human history, we have been dependent on machines to survive. Fate, it seems, is not without a sense of irony. " - Morpheus "Real men use mspaint for writing code and notepad for designing graphics." - Anna-Jayne Metcalfe

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                            • J JanapatiBalu

                              Hi, How can we get data or characters which is present on image.Actually i have captcha images in .JPEG extension and from that images i have to remove noise, extract the characters and then i have to convert the extracted characters in to string.So please give some idea how to proceed further.

                              J Offline
                              J Offline
                              jhwurmbach
                              wrote on last edited by
                              #15

                              The black hats did hire recently?


                              Failure is not an option - it's built right in.

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                              • D DavidNohejl

                                Dave Kreskowiak wrote:

                                What part of "YOU CAN'T DO THAT" don't you understand?

                                I am sorry Dave, I am afraid can't do that. :rolleyes:


                                "Throughout human history, we have been dependent on machines to survive. Fate, it seems, is not without a sense of irony. " - Morpheus "Real men use mspaint for writing code and notepad for designing graphics." - Anna-Jayne Metcalfe

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                                Brady Kelly
                                wrote on last edited by
                                #16

                                Hahahaha!!!:laugh::laugh:

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                                • J JanapatiBalu

                                  Dave i understood what u have suggested me. ok removing noise is difficult, but give some idea how can i extract data from captcha image.Give reply if u have idea about extracting data from image. Regards, Balu.

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                                  PlayByTheRules
                                  wrote on last edited by
                                  #17

                                  JanapatiBalu wrote:

                                  i understood what u have suggested me.

                                  Oh no you haven't!

                                  1 Reply Last reply
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