This paper presents TinyMotion, a pure software approach for detecting a mobile phone user’s hand movement in real time by analyzing image sequences captured by the built-in camera. We present the design and implementation of TinyMotion and several interactive applications based on TinyMotion. Through both an informal evaluation and a formal 17-participant user study, we found that 1. TinyMotion can detect camera movement reliably under most background and illumination conditions. 2. Target acquisition tasks based on TinyMotion follow Fitts ’ law and Fitts law parameters can be used for TinyMotion based pointing performance measurement. 3. The users can use Vision Tilt-Text, a TinyMotion enabled input method, to enter sentences faster than MultiTap with a few minutes of practicing. 4. Using camera phone as a handwriting capture device and performing large vocabulary, multilingual real time handwriting recognition on the cell phone are feasible. 5. TinyMotion based gaming is enjoyable and immediately available for the current generation camera phones. We also report user experiences and problems with TinyMotion based interaction as resources for future design and development of mobile interfaces. ACM Classification: H5.2 [Information interfaces and

Information navigation techniques for handheld devices support interacting with large virtual spaces on small displays, for example finding targets on a large-scale map. Since only a small part of the virtual space can be shown on the screen at once, typical interfaces allow for scrolling and panning to reach off-screen content. Spatially aware handheld displays sense their position and orientation in physical space in order to provide a corresponding view in virtual space. We implemented various one-handed navigation techniques for camera-tracked spatially aware displays. The techniques are compared in a series of abstract selection tasks that require the investigation of different levels of detail. The tasks are relevant for interfaces that enable navigating large scale maps and finding contextual information on them. The results show that halo is significantly faster than other techniques. In complex situations zoom and halo show comparable performance. Surprisingly, the combination of halo and zooming is detrimental to user performance.

This paper presents TinyMotion, a pure software approach that detects the movements of cell phones in real time by analyzing image sequences captured by the built-in camera. Typical movements that TinyMotion detects include- horizontal and vertical movements, rotational movements and tilt movements. In contrast to earlier work, TinyMotion does not require additional sensors, special scenes or backgrounds and can run on today’s main-stream camera phones without hardware modification. We describe the design and implementation of TinyMotion and analyze the potential interactions that can leverage TinyMotion. Three applications and two games were created to test TinyMotion. Benchmarking results and usability study show that TinyMotion can detect camera movement reliably under most background and illumination conditions.

As the capabilities of mobile devices grow, so do the potential uses for real-world interactions. Using commonly carried devices, such as cell phones and PDAs, to assist in routine tasks, such as using vending machines or ATMs, is an emerging area of ubiquitous computing. However, with the increase in potential uses, the potential for misuse and attacks also increase. In this paper, we present a secure method of using mobile devices to interact with real world objects. Our model uses two dimensional colorized barcodes to easily establish a secure link between mobile devices and service points. We discuss the model, its security, and potential uses for common tasks. We also discuss potential security concerns, and cover potential cases where this model could be used to both automate and control commonly performed tasks.

Active music performance can mean composition and interpretation of composed music or improvisation. In this paper we discuss the design requirements to make mobile handheld devices into actively engaged expressive musical instruments for these different types of performance. Candidate sensors are discussed and compared within this design space. 1.

In this paper, we describe a new interaction technique for mobile devices named Mixed Interaction Space that uses the camera of the mobile device to track the position, size and rotation of a fixed-point. In this demonstration we will present a system that uses a hand-drawn circle, colored object or a person’s face as a fixed-point to determine the location of the device. We use these features as a 4 dimensional input vector to a set of different applications.

We accepted 10 papers that will be presented within the workshop. We would like to thank the authors for their contributions and the organizers of Pervasive 2007 for hosting Permid 2007. We look forward to the workshop providing a rich environment for academia and industry to foster active collaboration in the area of mobile interactions with the real world.

Touch interaction with mobile phones enable users to have a more natural interaction with the device, since touch is a natural way of direct accessing an object of interest. But one disadvantage is occlusion; i.e., the user loses a high percentage of information presented on the small screen of the mobile phone during the interaction using his ”big finger”. On the other hand, interaction enhanced with accelerometers can react according to the device movements, e.g., while the user is tilting the mobile phone, the UI will be rotated. A drawback is that the user needs to move the whole device while interacting and consequently loses his eye contact on the phone’s screen (screen-absence problem). Finteraction (Finger Interaction) is a new interaction concept that solves the occlusion and screen-absence problems. User interact with a large public display using his mobile phone. Moving the index finger in front of the camera at the backside of the mobile phone, the user can interact with the large public display even on the move.