Method of electronically stabilizing a video image having

Abstract

A method of electronically stabilizing an image in the presence of jitter. The jitter induced error is measured prior to the beginning of each active sampling window signal and the error is computed into a corresponding number of pixel clock signal periods. The jitter is compensated for by advancing or delaying the occurrence of the beginning of each active sampling window signal relative to the transaction edge of the frame reference signal by the number of pixel clock signal periods. The jitter induced error is measured prior to the sampling edge of each active sample signal within each active sampling window signal. The error is converted into a corresponding number of pixel clock signal periods. The occurrence of the sampling edge of each subsequent active sample signal is advanced or delayed by the number of pixel clock signal periods corresponding to the jitter induced error. Thus, the sampling of the image is locked to the measured jitter and the image is stabilized in the presence of the jitter. The jitter error measurements are sampled once, twice, or more times prior to the field active starting edge. Error signals from a plurality of sources such as a scanner motor and a turret servo may be combined and compensated for together. The method of the invention may be employed to compensate for azimuth jitter, vertical jitter, or jitter with reference to any chosen axis.