Ghost Font: A font that humans can read but AI cannot
A project called “Ghost Font” presents animated text that appears as TV-like static in any single frame but becomes legible to the human eye through motion, with the aim of being readable by people yet hard for AI to decode. Commenters note that current vision models can already extract both the main and decoy messages using straightforward techniques like optical flow, frame differencing and temporal averaging, making this more of a temporary obfuscation than a durable defense. Many also highlight usability and accessibility problems—some humans struggle to read it at all—and argue that such tricks are part of an ongoing, likely unwinnable cat‑and‑mouse game between CAPTCHA-style tests and increasingly capable AI.
Can AI Actually Read “Ghost Font”?
- Many commenters say the claim “humans can read it but AI cannot” is already false.
- Frontier models (GPT 5.6, Claude, Gemini, Fable) reportedly decode the animated text when given the video and no special instructions, often via optical-flow / motion-based analysis.
- Several people share code or algorithms using frame differencing, phase correlation, optical flow, temporal averaging, or video compression artifacts to reveal the text and then OCR it.
- However, early or naive attempts often only pick up the decoy static message (“WRITTEN IN GHOST FONT”), not the user-entered animated one, leading to confusion about what “success” means.
Decoy vs. Actual Message Confusion
- The demo embeds two messages:
- A faint, static, low-frequency decoy visible in screenshots or long exposure.
- The real, motion-defined text that only appears through temporal changes.
- Many humans and AIs initially see only the decoy; commenters describe this as a major UX/communication flaw of the demo.
Is It Really a “Font”?
- Several argue it’s not a font but a video/animation effect, since each glyph is defined over time rather than as a static shape.
- Some note that a single frame is effectively noise, so talking about “font” in the traditional sense is misleading.
Human Readability & Accessibility
- Some readers find it “clear as day”; others can barely read it or not at all, citing astigmatism, age, or screen characteristics.
- Comparisons are made to Magic Eye images and motion illusions.
- Multiple comments flag serious accessibility problems, including incompatibility with screen readers and likely conflicts with disability regulations.
Usefulness, CAPTCHA, and Arms Race
- Suggested uses: CAPTCHAs, anti-scraping, steganography, “AI-safe” writing.
- Many doubt long-term viability: once the decoding technique is known, models or tools can automate it, and temporal analysis is straightforward.
- Some propose randomizing motion/noise parameters per-client to slow learning, but others see this as classic security-through-obscurity and part of a never-ending AI–CAPTCHA arms race.
Related / Alternative Obfuscation Ideas
- Mention of homograph tricks, Unicode-mangling fonts (“Noroboto”), PDFs with remapped glyphs, psychedelic/qualia-based cryptography, and motion or illusion-based schemes that privilege certain human perceptions.