Voice-bandwidth visual communication through logmaps: the Telecortex

Presents a robotic video telephone application of the Cortex-1 miniaturized space-variant active vision system. The embedded processor architecture of Cortex-1 enables it to implement a variety of functions not found in conventional video telephones, for example the camera tracks moving users with its pantilt mechanism. The authors also report an analog channel coding scheme to transmit logmap video images through band-limited analog channels such as the public switched telephone network (PSTN). The transmitter divides the frequency band into 768 channels, and modulates two values in quadrature on each channel. Some channels are reserved for special calibration signals enabling the receiver to recover both the phase and magnitude of the transmitted signal. The remaining channels carry pixel intensities