The Information in Temporal Histograms

Abstract

In many circumstances the limitation for use of video cameras is energy. The energy needed for compression and transmission of video is substantial, and is linear with the number of transmitted frames. Time-lapse photography, a drastic reduction of transmitted frame rate, is an obvious solution, say by transmitting one frame every several minutes. The temporal resolution of the video is lost. Can we reduce the number of transmitted frames but still keep some information in the original frame rate? In this work we examine a new paradigm for static cameras, the Histogram Camera. Frames are examined (but not coded or transmitted) at video frame rate, and for each pixel a temporal histogram of the intensity values is maintained. These temporal histograms, one per pixel, are transmitted at the reduced frame rates. It is shown that objects that change status from moving to stationary or vice versa can be extracted from the pixel-wise temporal histograms at high temporal accuracy. A storyboard summary of the video between frame transmissions can be generated. In addition, objects extracted from temporal histograms enable both background reconstruction, and matching across cameras with very different viewpoints. These benefits suggests that the Histogram Camera may be an important part of future very low frame rate cameras.