Circuit for adaptively separating luminance and color signals based on expended vertical and horizontal correlations and method therefor

A circuit for separating luminance and color signals from a composite video signal in an NTSC type picture processing system, said circuit comparing:

• sample signal generating means for delaying said composite video signal through a plurality of line and sample delay elements, thereby generating a reference sample signal and a plurality of respective delayed sample signals;
• first filtering means for detecting respective correlations between said reference sample signal and the respective delayed sample signals, said delayed sample signals being respectively separated from said reference sample signal in upper/lower/left/right directions and being in-phase with respect to said reference sample signal, and for separating and filtering said luminance and color signals from said composite video signal in a respective direction of that one of said delayed sample signals having a maximum correlation with respect to said reference sample signal;
• second filtering means for separating and filtering said luminance and color signals from said plurality of delayed sample signals, generated from said sample signal generating means, in a plurality of predetermined directions;
• correlation detecting means for detecting horizontal and vertical correlations between said reference sample signal and respective ones of said delayed sample signals which are separated from said reference sample signal in the upper/lower/left/right directions and which are out of phase with said reference sample signal;
• and
• filter selecting means for selecting one of respective outputs from said first filtering means and said second filtering means responsive to said horizontal and said vertical correlations and predetermined filter selecting threshold values.

A circuit for separating luminance and color signals from a composite video signal in an NTSC type picture processing system, said circuit comprising:

• sample signal generating means for delaying said composite video signal through a plurality of line and sample delay elements and then generating a plurality of respective sample signals;
• direction determining means for determining the direction from among upper, lower, left and right directions of the one of the respective sample signals having a maximum correlation with respect to a reference sample signal to thereby output a respective direction control signal, wherein the correlation indicates the existence of an edge in the video signal oriented in one of upper, lower, left and right directions with respect to said reference sample signal;
• and
• filtering means for separating and for filtering said luminance and color signals from said composite video signal in a direction corresponding to said direction control signal.