Petri Honkamaa

Augmented reality with large 3D models on a PDA: implementation, performance and use experiences

We have implemented a client/server system for running augmented reality applications on a PDA device. The system incorporates various data compression methods to make it run as fast as possible on a wide range of communication networks, from mobile phone links to WLAN, We provide a detailed description of various implementation issues, data compression optimisations, and performance analysis of the system, Usability of the system is evaluated in a demanding architectural application, with a large virtual building rendered in an outdoors location.

A lightweight approach for augmented reality on camera phones using 2D images to simulate 3D

We describe a lightweight augmented reality approach enabling arbitrarily complex virtual models to be operated even on low end camera phones. For optimal performance we apply simple motion tracking with manual initialization, and sequences of 2D images to give illusion of three dimensions. Our approach enables also augmenting of real objects, not just virtual ones. A prototype implementation of the solution exists for Series 60/Symbian OS mobile phones. Augmented interior design is presented as the main application example.

Construction and evaluation of multi-touch screens using multiple cameras located on the side of the display

We applied a computer vision based method and developed multi-touch technology to be adopted in various display types. In the selected design, multiple cameras are placed on the side of the display with their optical axis parallel to the screen. The display edges opposite the cameras are illuminated and fingers are detected since they block the light in the camera images. The approach is scalable and can be used in a wide variety of displays. Due to self-occlusion of the touchpoints, it is challenging to relate camera measurements to tracked points. In this paper, we present our approach for tracking and managing multiple touchpoints in such camera set-ups. We describe the mathematical background for modeling and calibrating the cameras, the design of the extended Kalman filter for point tracking, and the logic for adding, updating and removing the touchpoints. We analyze the potential accuracy and robustness of the system using several simulations and present two different real-life implementations of the approach.

May Day masks augmented on mobile phones

In this paper we describe a fun application of augmenting masks on peoples faces using mobile camera phones. The application was published on May Day 2008 in Finland, gaining thousands of visitors and downloads within a couple of days. We provide a description of the user interface and implementation issues, as well as analysis of user statistics and their comments.