Showing papers on "Residual frame published in 1973"

Conditional replenishment video encoder with low-frequency compensation

Abstract: Video signal samples for all of the picture elements in a frame interval are stored in a frame memory and each new video signal sample is compared with its corresponding sample from the frame memory in order to develop a frame-to-frame difference signal. A movement detector utilizes the frame-to-frame difference signals to determine when a new video signal sample should be utilized to update the old sample stored in the frame memory and be transmitted to the receiving location. An address word accompanies the transmitted video signal amplitude in order to indicate to the receiver the location of the amplitude within the frame interval. Frame-to-frame differences not indicated as belonging to a moving area are integrated for an entire video line interval. If the integration result exceeds a predetermined threshold, indication of this fact is transmitted to the receiver during the horizontal blanking interval. In addition, a compensation value is developed in response to this indication, and this value is utilized during the next video line interval to modify all of the picture element amplitudes stored in the frame memory for that video line interval. As a result, stored picture element amplitudes are changed en masse for an entire line interval in response to low-frequency changes of the type which occur as a result of changes in light intensity.