CAPTCHA Breaking Scripting Language

Introduction

The CAPTCHA Breaking Library and Scripting Language provides the necessary tools for quickly creating a program capable of reading text out of an image. The actual job of determining which letter is in a given image is done with the help of Neural Networks, Contour Analysis, and Bitmap Vector Subtraction.

CAPTCHAs that are able to be segmented by color (i.e., each letter is a different color) may first be converted to a perceptive color space where distances between colors are mathematically determined based on how the human eyes perceive color, not how colors are different in the RGB color-space. This allows most multicolor CAPTCHAs to be solved quite trivially.

Documentation

To get started, check out the hello world tutorial, the language syntax, and the solver walkthrough.

Example

Here is a code snippet written in CBL that breaks a CAPTCHA originally from here.

**********************************************************
* Scott Clayton                           April 14, 2012 *
**********************************************************
* This script is part of the CBL interpreter:            *
* http://code.google.com/p/captcha-breaking-library/     *
**********************************************************
* The CAPTCHA that this script breaks came from:         *
* http://www.codeproject.com/Articles/5947/CAPTCHA-Image *
**********************************************************

SetMode,        all
SetupSegmenter, BLOB, 4, 14, 8
SetupSolver,    MNN, "0123456789", 20, 20, 8, 150, 0.95
Load,           "mnn.solver.db"

DefinePreconditions
   Resize,           400, 100
   Subtract,         "merge3.bmp"
   Invert
   Median,           1
   MeanShift,        1, 2, 5
   Binarize,         150
   ColorFillBlobs,   80, 52
   RemoveSmallBlobs, 90, 4, 14
   HistogramRotate
   Binarize,         200
   ColorFillBlobs
EndPreconditions

Solve, %IMAGE%

Here's the CBL GUI running the script you see above on a CAPTCHA:

Notepad++ Plugin

Be sure to install the Notepad++ syntax highlighting plugin on the downloads page to get syntax highlighting for CBL. Installation instructions are included in the Readme.txt file in the download.

Scott

Exported from my old Google Code repository.