US RE40,074 E1
Reduced television display flicker and perceived line structure with low horizontal scan rates
Donald S. Butler, Cupertino, Calif. (US); Xu Dong, San Jose, Calif. (US); and Jack J. Campbell, San Francisco, Calif. (US)
Assigned to Genesis Microchip Inc., Santa Clara, Calif. (US)
Filed on Jul. 21, 2005, as Appl. No. 11/188,285.
Application 11/188285 is a reissue of application No. 09/654938, filed on May 10, 2000, now 6,597,402, filed on Jul. 22, 2003.
Int. Cl. H04N 7/01 (2006.01)
U.S. Cl. 348—447  [348/443; 348/910] 21 Claims
OG exemplary drawing
 
1. A method for deriving an interlaced television signal from an interlaced 625 line, nominally 50 Hz field rate television signal, the derived television signal having perceived reduced line structure and perceived reduced flicker, comprising
increasing the number of lines in each field of the derived television signal with respect to the number of lines in each field of the original television signal, such that the increase in lines reduces perceived line structure in the derived television signal, said increasing the number of lines comprising
de-interlacing the original television signal to produce a progressively scanned 625 line, nominally 50 Hz frame rate television signal, and
increasing the number of lines in each frame of the progressively scanned television signal, and
after increasing the number of lines in each field, increasing the field rate of the derived television signal with respect to the field rate of the original television signal, such that the increase in field rate reduces perceived flicker in the derived television signal, said increasing the field rate comprising
reinterlacing the progressively scanned television signal such that for some progressively scanned frames a pair of interlaced fields are derived and for selected progressively scanned frames only one interlaced field is derived, whereby selected ones of the potential interlaced fields are dropped,
wherein the increase in the field rate and the increase in the number of lines in the derived television signal results in a horizontal scanning rate that does not substantially exceed twice the horizontal scanning rate of the original television signal while minimizing undesirable motion artifacts.