1. CAPTCHA image acquisition → 2. Preprocessing (grayscale, thresholding, noise removal) → 3. Segmentation (character isolation) → 4. Recognition (CNN/RNN) → 5. Output text (simplified from typical repos):
1. Executive Summary GitHub hosts numerous open-source projects aimed at solving CAPTCHAs using artificial intelligence (primarily computer vision and deep learning). These solvers target text-based, image-based, and audio CAPTCHAs. While valuable for security research and automation testing, they raise ethical and legal concerns regarding unauthorized bypassing of website protections. 2. Common CAPTCHA Types Targeted | CAPTCHA Type | AI Approach | Example Projects | |--------------|--------------|------------------| | Text-based (distorted characters) | CNN, RNN, CTC loss | captcha_break, simple_captcha_solver | | Image-based (e.g., reCAPTCHA image grid) | YOLO, Faster R-CNN (object detection) | recaptcha_ solver (deprecated) | | Audio CAPTCHA | Spectrogram + CNN / LSTM | audio_captcha_solver | | Math / Logic CAPTCHA | OCR + regex / simple rules | math_captcha_solver | 3. Notable GitHub Repositories | Repository | Stars (approx.) | Technique | Main Language | Status | |------------|----------------|-----------|---------------|--------| | captcha_break by zhengwh | 1.5k | CNN + custom preprocessing | Python | Inactive | | simple_captcha_solver by puthz | 800 | Keras CNN | Python | Inactive | | CNN_character_captcha by JasonLiTW | 500 | TensorFlow CNN | Python | Archived | | captcha_solver by cricdata | 300 | Generative adversarial + CNN | Python | Inactive | | generic_captcha_solver by JackonYang | 200 | Transfer learning (InceptionV3) | Python | Inactive | Note: Many popular CAPTCHA solvers are taken down due to policy violations or DMCA requests from Google (reCAPTCHA) and other providers. 4. Typical Technical Pipeline A standard AI CAPTCHA solver on GitHub follows this process: ai captcha solver github