A New Crispener Circuit for Television Images

The subjective definition of a television image may be improved by overemphasizing and/or increasing the steepness of its luminance transitions. A new crispener circuit capable of performing either or both these functions using linear circuitry is described and illustrated with low-resolution television images. It is shown that the effect of overemphasizing or steepening the rise-times of the luminance transitions appear to be comparable in improving the subjective quality of the resulting picture whereas a combination of the two is superior to either. Applications of the crispener circuit in outlining television images and reducing overshoot and ring due to sharp cutoff filter characteristics are also described and illustrated. It is shown that when the ring and overshoot in an image are reduced, the sharpness of the image is likewise reduced.

Print ISSN

0361-4573

Published

1963-11

Content type

Original Research

DOI

10.5594/J15425