Abstract: A video system comprises a video display having a wide format display ratio for displaying a video signal. A signal processor has an interpolator and a first in first out line memory having asynchronous write and read ports for selectably expanding and compressing a picture represented by data in the video signal. The picture is cropped to define a subset of the picture for display by controlling writing of the data into the line memory. A microprocessor for controls provides control signals with selectable time durations and selectable phases relative to a synchronizing component of said video signal for selecting boundaries of the subset of the picture for display. The microprocessor can select the time durations and the phases responsive to user commands.

Abstract: A television apparatus comprises a display for a video signal and a panning control circuit. The panning control circuit counts the horizontal lines, or half lines, and generates a vertical reset signal delayed by a variable pan delay relative to the vertical synchronizing component of the video signal. The pan delay varies in a first range for vertically panning the video signal down and varies in a second range for vertically panning the video signal up. The first and second ranges are mutually exclusive to control interline flicker of the panned video signal when successive fields have different numbers of horizontal lines. The first range is less than the number of horizontal lines in each field and the second range is greater than the number of horizontal lines in each field and less than the number of horizontal lines in each frame.

Abstract: A video display control system, comprises a video display having a first format display ratio. A picture height circuit determines an active video picture height from an input video signal having a second format display ratio. A detector circuit identifies letterbox formats responsive to the active video picture height in the video signal and determines a format display ratio of the letterbox picture. A zoom control circuit is operable in a first mode of operation for enlarging the picture in size to fill the display substantially entirely, notwithstanding consequent cropping of the picture, and operable in a second mode of operation for enlarging the picture in size to substantially fill the display vertically, notwithstanding consequent unused portions of the display. A vertical pan control circuit automatically centers the picture in both modes of operation.