Imprinto: Enhancing Infrared Inkjet Watermarking for Human and Machine Perception

TL;DR

Imprinto introduces an infrared inkjet watermarking method that embeds invisible digital content into paper documents, enhancing hybrid interfaces without affecting aesthetics, and is detectable by machine learning techniques.

Contribution

The paper presents a novel IR inkjet watermarking technique, an optimized authoring tool, and demonstrates practical applications for augmented paper interfaces.

Findings

IR ink can be used invisibly without affecting background perception

Machine learning pipeline effectively detects IR content

Optimized IR embedding balances invisibility and detectability

Abstract

Hybrid paper interfaces leverage augmented reality to combine the desired tangibility of paper documents with the affordances of interactive digital media. Typically, virtual content can be embedded through direct links (e.g., QR codes); however, this impacts the aesthetics of the paper print and limits the available visual content space. To address this problem, we present Imprinto, an infrared inkjet watermarking technique that allows for invisible content embeddings only by using off-the-shelf IR inks and a camera. Imprinto was established through a psychophysical experiment, studying how much IR ink can be used while remaining invisible to users regardless of background color. We demonstrate that we can detect invisible IR content through our machine learning pipeline, and we developed an authoring tool that optimizes the amount of IR ink on the color regions of an input document for machine and human detectability. Finally, we demonstrate several applications, including augmenting paper documents and objects.