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Flexible Hardware Configurations for Studying Mobile Usability

Antti Oulasvirta and Tuomo Nyyssönen

Journal of Usability Studies, Volume 4, Issue 2, February 2009, pp. 93-105

Article Contents


Cameras

As in ARMIv1, the cameras are the core of the system. In general, selecting camera elements are a matter of balancing performance, size, cost-efficiency, and versatility.

In ARMIv2, all miniature cameras were equipped with an automatic electric shutter and white balance. Camera elements were originally bought as miniature dome surveillance cameras that were modified for pole attachment. A miniature audio amplifier and a microphone, originally from the same surveillance product, were also re-housed and modified. Images from these cameras on the pole (see Figures 2 and 6) are in the PAL format, still effective image quality is approximately 280 TV-lines or less. The necklace camera element performance is 350 TV-lines with dimensions of 30(H) x 30 (W) x 34 (D) mm and weighing 30 grams.

The environmental cameras provided full quality in PAL resolution, by one chip computer-controlled display (CCD) and programmability and versatility for all light conditions. When equipped with wide-angle lenses, the camera view can cover a space size of a meeting room. A practical limitation is posed by the fact that all video streams are integrated into one, which lowers the quality of any single stream. According to our experience, environmental cameras work best in small spaces like desktops and hallways. For outdoor experimenting, moderator-controlled camera operation is a better option.

Figure 3. System diagram for the current setup

Figure 3. System diagram for the current setup

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