This script generates CAPTCHAs using the pulfrich effect, making it visually impossible to detect using traditional OCR algorithms.

For best effect, cover your right eye with a sunglass or some other translucent object.

https://skaffa.github.io/pulfrich-captcha/

I consider this a Proof of Concept

In the 'captchas' folder are some examples

Note: This project is mostly made by AI. ChatGPT and Deepseek were used for this. If for some reason anyone decides to contribute to this repo, I recommend using AI generated code, to not waste your time. Otherwise, fork or clone this repo and do whatever with it.

Important

Unfortunately, the current implementation still leaks enough signal for the correct CAPTCHA code to be programmatically recovered. Using an optical-flow–based analysis, attackers can extract motion differences that reveal the underlying characters.
https://github.com/skaffa/pulfrich-captcha/blob/main/flow_attack.py