Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA), is a public fully automatic program that distinguishes users from computers or people. This thesis developed a CAPTCHA recognition system that can be deployed on the NAO robot, a humanoid robot to pass the Turing test and also can be deployed on web services in order to provide a recognition service. The recognition system uses convolutional neural network to extract features in CAPTCHA image and encode data with one-hot encoding system which is widely used in multiclassification. Python is the programming language used in developing this project, TensorFlow and Keras library are used to easily establish a neural network. NAO robot version is v5 and code testing is on Ubuntu 16.04 release. The final recognition model showed about 99.67% accuracy on train dataset and 98.10% accuracy on test dataset with suitable optimizer and loss function. According to the one-hot encoding features when regulated data, the accuracy is a bit high than it performed in real applications. Due to a large amount of CAPTCHA data for the combination of numbers and letters, the CAPTCHA in this thesis dataset consists only of numbers, which could be improved by using datasets contains numbers and letters CAPTCHA. ; Video Link: https://youtu.be/4pxHi9h1caU


    Zugriff

    Download


    Exportieren, teilen und zitieren



    Titel :

    CAPTCHA Recognition System


    Beteiligte:
    Zhu, Wenhao (Autor:in)

    Erscheinungsdatum :

    2019-01-01


    Medientyp :

    Sonstige


    Format :

    Elektronische Ressource


    Sprache :

    Englisch



    Klassifikation :

    DDC:    629



    DRONE CAPTCHA

    WELDEMARIAM KOMMINIST / SAILER ANCA / PICKOVER CLIFFORD A | Europäisches Patentamt | 2019

    Freier Zugriff

    Drone captcha

    WELDEMARIAM KOMMINIST / SAILER ANCA / PICKOVER CLIFFORD A | Europäisches Patentamt | 2020

    Freier Zugriff


    Recognizing Objects in Adversarial Clutter: Breaking a Visual CAPTCHA

    Mori, G. / Malik, J. / IEEE | British Library Conference Proceedings | 2003


    RECOGNITION SYSTEM, RECOGNITION DEVICE, RECOGNITION METHOD, AND RECOGNITION PROGRAM

    SHIBATA YOSHIHISA / YAMAZAKI SUGURU / SHIMIZU SHUN et al. | Europäisches Patentamt | 2023

    Freier Zugriff