Scanning Sequence and Repetition Rate of Television Images

Abstract

This paper considers factors which affect the apparent steadiness of television images: namely, line flicker, flicker of the image as a whole, alternatingcurrent ripple in the defecting circuits, alternating-current ripple in the video frequency signal, and various kinds of beating of the alternating-current ripple with the various scanning frequencies. It is concluded that an integer ratio between alternating-current ripple frequency and frame frequency is very desirable for progressive scanning and is almost imperative for interlaced scanning. Interlaced scanning with a frame frequency of thirty per second and a field frequency of sixty per second fulfills the requirements in regard to flicker and the relations to alternatingcurrent ripple frequency for a sixty-cycle power source, and offers considerable net gain over other scanning procedures considered. The problems of both odd-and evenline methods of interlacing are discussed and the odd-line method is found preferable.

Motion silencing of flicker distortions on naturalistic videos

“…To mitigate flicker defects, variations on the Kell factor [23], which perceptually limits the bandwidth of a temporally sampled image to avoid the visibility of irritating beat frequencies, have been devised, while a variety of deinterlacing techniques [24] were proposed to reduce flicker including temporal anti-alias filters, interpolation, and motion-compensated up-conversion. Flicker also can be observed in quantized or compressed videos due to spatially localized temporal fluctuations of luminance: for example, caused by blockiness over textures or blockiness at the junction of blocks, called corner outliers.…”