| 摘要 |
A television picture stabilizing system for deriving from an input video signal exhibiting unsteadiness due to having been produced by an unsteady television camera, a corrected video signal essentially free of such unsteadiness, without destroying intentional panning and tilting of the camera, in which a detector (24, 26) selects from an input video signal (10) a reference within the camera field of view, which reference but for the camera unsteadiness would normally be stationary, against which picture motion is measured. Motion of the selected reference is measured with a position counter (80) and comparator (84) which produces a correction signal ( DELTA P) representative of the measured motion. The correction signal ( DELTA P) controls the delay of a digital frame store (16), to which the input video signal is applied, eliminating the unsteadiness in the overall television picture. In a system for providing both horizontal and vertical stabilization, the reference consists of a horizontally disposed edge (40) and a vertically disposed edge and separate position counters are provided for continually measuring their motion from field to field. The reference edges are tracked by respective tracking windows (50). Preferably the tracking windows are locked onto their respective reference edges despite up and down and side-to-side movement of the reference edges. An initial horizontal position of the vertical tracking window and an initial vertical position of the horizontal tracking window are stored in digital memories (not shown), which memories are respectively responsive to measured side-to-side motion and measured up and down motion automatically to alter the horizontal position of the vertical tracking window and the vertical position of the horizontal tracking window. |
