PaperCAD: A System for Interrogating CAD Drawings Using Small Mobile Computing Devices Combined with Interactive Paper

Weesan Lee,Thomas F Stahovich

doi:10.1155/2014/908690

Abstract

Smartphones have become indispensable computational tools. However, some tasks can be difficult to perform on a smartphone because these devices have small displays. Here, we explore methods for augmenting the display of a smartphone, or other PDA, using interactive paper. Specifically, we present a prototype interface that enables a user to interactively interrogate technical drawings using an Anoto-based smartpen and a PDA. Our software system, called PaperCAD, enables users to query geometric information from CAD drawings printed on Anoto dot-patterned paper. For example, the user can measure a distance by drawing a dimension arrow. The system provides output to the user via a smartpen’s audio speaker and the dynamic video display of a PDA. The user can select either verbose or concise audio feedback, and the PDA displays a video image of the portion of the drawing near the pen tip. The project entails advances in the interpretation of pen input, such as a method that uses contextual information to interpret ambiguous dimensions and a technique that uses a hidden Markov model to correct interpretation errors in handwritten equations. Results of a user study suggest that our user interface design and interpretation techniques are effective and that users are highly satisfied with the system.

Highlights

Smartphones, and the wide variety of software applications for them, have become indispensable computational tools
The log files that the PaperCAD system captured during the user study enabled us to perform a detailed analysis of the system’s performance and usability
We have presented a prototype user interface for augmenting the display of a smartphone, or other PDA, using interactive paper

Summary

Introduction

Smartphones, and the wide variety of software applications for them, have become indispensable computational tools. We explore methods for augmenting a smartphone display using interactive paper. We present a prototype interface that enables a user to interactively interrogate technical drawings using an Anoto-based smartpen [1] and a PDA. Smartpens serve the same function as a traditional pen and record the writing as time-stamped pen strokes. Smartpens are used with paper preprinted with a special dot pattern. A camera integrated into smartpen uses the dots to locate the pen tip on the page and digitize each pen stroke. Some smartpens process the digitized writing using application software running on a processor embedded in the device; other versions wirelessly transmit the digitize writing so that it can be processed by software running on a computer, smartphone, or another mobile computing device

Results

Discussion

Conclusion