Photographic/videographic memory system architecture

The architecture of the author's early WearCam systems typically involved a mixture of digital and analog video signals, along with a hybrid (digital and analog) communications network, as depicted in Fig 3.

  

Figure 3: Block diagram of early Personal Imaging body-worn system hardware. The processor (computer), was connected to a communications system, and therefore, to other computers at remote locations (either worn by other people, or fixed in the environment) by a digital data link. The computer also controlled parameters (settings) of an analog NTSC video camera as well as an NTSC video switcher/mixer, so that the analog video from the camera could be routed to the NTSC display, providing a viewfinder function. The processor (computer) also produced an NTSC output that was fed to the video mixer for overlays. Moreover, video from the camera could instead be directed first through the processor prior to display, so that the visual perception of reality could be altered (mediated). The computer-controlled video switcher facilitated either locally mediated reality (by way of the body-worn processor), or remotely mediated reality (simultaneously sending and receiving analog NTSC video over the communications link for remote processing) or a combination of both of these.

There were three possible video signal paths that could be switched, selected, or mixed in various proportions, as desired, by way of the computer-controlled analog NTSC video switcher/mixer. These three signal paths comprised:

• Direct path from video camera to display.
• Locally mediated path from camera, through processor, to display.
• Remotely mediated path from camera, through remotely located processor (by way of communications system), to display.

This architecture also provided a mixture of local and remote video recording/archival capabilities which proved useful for the acquisition, production, editing, and dissemination of documentary videos, etc..