Abstract

Captcha has been designed to be easy for humans and hardon the machines. Captcha are used by many websites to determinehuman users from indecent programs. This paper will propose two typesfor generating captcha these are; text and image captcha. In the first typeuse (6*6) captcha table to store alphabetic characters 'A'..'Z' and '0'..'9'and use random function to generate six numbers to represent the rowand colum numbers which used as index to retrieve the character fromthe captcha table to get the final captcha. In the second types a sample of100 images from PayPal.com Human Interactive Proofs (HIP) are used. Inorder to recognize these images three steps for recognize the characters(pre-processing, segmentation and classification) are adopted. Themodification was in the preprocessing step where proposing to useGabor filter to remove the noise in the images which make the recognitionaccuracy 100% which is good results when compared with the obtainedaccuracy in reference [1] where the accuracy value in the range (80% ..98%) for different scheme used in this work.

Keywords

The article was added to IASJ on 2016-10-25

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