A Foveated Imaging System to Reduce Transmission Bandwidth of Video Images from Remote Camera Systems 6

We have developed a preliminary version of a foveated imaging system, implemented on a general purpose computer, which greatly reduces the transmission bandwidth of images. The system is based on the fact that the spatial resolution of the human eye is space variant, decreasing with increasing eccentricity from the point of gaze. By taking advantage of this fact, it is possible to create an image that is almost perceptually indistinguishable from a constant resolution image, but requires substantially less information to code it. This is accomplished by degrading the resolution of the image so that it matches the space-variant degradation in the resolution of the human eye. Eye movements are recorded so that the high resolution region of the image can be kept aligned with the high resolution region of the human visual system. This system has demonstrated that significant reductions in bandwidth can be achieved while still maintaining access to high detail at any point in an image. The system has been tested using 256x256 8 bit gray scale images with 20° fields-of-view and eye-movement update rates of 30 Hz (display refresh was 60 Hz). Users of the system have reported minimal perceptual artifacts at bandwidth reductions of up to 94.7% (18.8 times reduction)