Television Vertical Aperture Compensation

The known ways of compensating in the vertical direction for a scanning aperture are reviewed. A new method is presented. This consists of wobbling the scanning aperture in and out of focus at a rapid rate, yielding high- and low-resolution signals. The low-resolution signal is subtracted from the high-resolution signal, yielding an aperture-compensated, or edge-enhanced, picture independent of the scanning direction. A similar method using vertical deflection wobble rather than focus wobble results in vertical aperture compensation alone. Pictures are shown to illustrate the subjective improvements obtainable using vertical aperture compensation.