StegaStamp: Invisible Hyperlinks in Physical Photographs

Printed and digitally displayed photos have the ability to hide imperceptible digital data that can be accessed through internet-connected imaging systems. Another way to think about this is physical photographs that have unique QR codes invisibly embedded within them. This paper presents an architecture, algorithms, and a prototype implementation addressing this vision. Our key technical contribution is StegaStamp, a learned steganographic algorithm to enable robust encoding and decoding of arbitrary hyperlink bitstrings into photos in a manner that approaches perceptual invisibility. StegaStamp comprises a deep neural network that learns an encoding/decoding algorithm robust to image perturbations approximating the space of distortions resulting from real printing and photography. We demonstrates real-time decoding of hyperlinks in photos from in-the-wild videos that contain variation in lighting, shadows, perspective, occlusion and viewing distance. Our prototype system robustly retrieves 56 bit hyperlinks after error correction -- sufficient to embed a unique code within every photo on the internet.

1. Introduction

Our vision is a future in which each photo in the real world invisibly encodes a unique hyperlink to arbitrary information. This information is accessed by pointing a camera at the photo and using the system described in this paper to decode and follow the hyperlink. In the future, augmented-reality (AR) systems may perform this task continuously, visually overlaying retrieved information alongside each photo in the user's view.