US 5,475,445 A · Motion adaptive luminance signal and color signal separation filter

Abstract

A filter is used for separating luminance and color signals from a composite color television signal in which the frequency of the color signal is multiplexed over the high-frequency region of the luminance signal. When a picture is detected with respect to its motion under frame correlation, and if that motion is relatively small, the separation of luminance and color signals is performed based on interframe correlation. If the motion is relatively large, the separation of luminance and color signals is made based on interfield correlation. The luminance and color signal separation based on the interfield correlation is attained from a correlation with signals in fields spaced forwardly and rearwardly away from the subject field by one field. This is accomplished by selecting a calculation having the highest among a plurality of calculations for an objective sample point and a plurality of sample points located about the objective sample point. Such a correlation is determined by checking the correlation of image signals in the set of sample points which are spaced apart from one another by one frame and located around the objective sample point.

Claims46

Dependent claims

A motion adaptive luminance and color signal separating filter for separating luminance and color signals from a composite color television signal in which the frequency of the color signal is multiplexed over the high-frequency region of the luminance signal, said filter including an interfield correlation device for separating the luminance and color signals in response to interframe correlation, the interfield correlation device comprising:

(A) luminance and color signal separating means for adding and subtracting a signal indicative of an objective sample point in a first field (n-field) and a plurality of signals indicative of sample points located proximate to the objective sample point in a picture and within fields (n-1 and n+1 fields) previously and subsequently adjacent to said first field, to provide a correlation between three fields which is utilized in turn, to perform separation of the color and luminance signals;
(B) correlation detecting means for calculating a difference signal in a set of the sample points whose chrominance subcarriers are in phase between the frames and spaced away from one another by one frame, the calculated difference signal being used to detect a direction of higher correlation for a set of sample points located about said objective sample point;
and
(C) selection means for selecting sample points having a direction of higher correlation in said luminance and color signal separating means, based on the direction of correlation detected by said correlation detecting means, to thereby select one set of sample points in which to perform separation of the color and luminance signals using the interfield correlation device.

1 more element

A device for separating a luminance signal from a composite color signal comprising:

a three-field separating circuit which receives a composite color signal and separates a luminance signal from the composite color signal by processing a composite color signal from a first field, a composite color signal from a second field, and a composite color signal from a third field, said first field containing an objective point, said three-field separating circuit including,
first means for producing a first and second signal, each first and second signal being a higher frequency component of the luminance signal produced by using said objective point, a sample point in said second field, and a sample point in said third field,
second means for producing a third signal having a lower frequency component of luminance signal produced by Using the composite color signal at said objective point and the color composite signal at a sample point in said second field, and
adding means for adding one of said first and second signals with said third signal to produce the luminance signal.

1 more element

A method for producing a luminance signal from a composite color signal comprising the steps of:

(a) separating a luminance signal from the composite color signal by using a composite color signal from a first field, a composite color signal from a second field, and a composite color signal from a third field by,
(a1) producing a first and second signal, each first and second signal being a higher frequency component of the luminance signal produced by using the objective point, a sample point in the second field and a sample point in the third field;
(a2) producing a third signal having a lower frequency component of the luminance signal produced by using the composite color signal at the objective point and the color composite signal at a sample point in the second field;
and
(a3) adding one of the first and second signals with the third signal to produce the luminance signal.

2 more elements

A method for producing a luminance signal from a composite color signal comprising the steps of:

(a) developing a first luminance signal from the composite color signal;
(b) generating three distinct separated higher frequency luminance signal portions from the composite signal, each said higher frequency luminance signal portion being derived from a composite signal of a first field and a composite signal of a second field;
(c) evaluating a correlation relationship between points in different fields;
(d) selecting one of the three higher frequency luminance signal portions in accordance with the correlation evaluation;
and
(e) combining said first luminance signal and said selected one of said higher frequency luminance signal portions to produce a more accurate luminance signal.

3 more elements

A method for motion adaptive separating luminance and color signals from a composite color television signal in which the frequency of the color signal is multiplexed over the high-frequency region of the luminance signal, said filter including an interfield correlation device for separating the luminance and color signals in response to interframe correlation, the interfield correlation device comprising the steps of:

(a) adding and subtracting a signal indicative of an objective sample point in a first field and a plurality of signals indicative of sample points located proximate to the objective sample point in a picture and within fields previously and subsequently adjacent to the first field, to provide a correlation between three fields which is utilized, to perform separation of the color and luminance signals;
(b) calculating a difference signal for a set of the sample points whose chrominance subcarriers are in phase between the frames and spaced away from one another by one frame, the calculated difference signal being used to detect a direction of higher correlation for a set of sample points located about the objective sample point;
and
(c) selecting a sample point having a direction of higher correlation based on the direction of correlation detected by said step (b), thereby selecting one of the three fields in which to perform separation of the color and luminance signals using the interfield correlation device.

1 more element

A device for producing a luminance signal from a composite color signal comprising:

first luminance signal development means for developing a first luminance signal from the composite color signal;
separating means for generating three distinct separated higher frequency luminance signal portions from the composite signal, each said higher frequency luminance signal portion being derived from a composite signal of a first field and a composite signal of a second field and for outputting said three distinct separated higher frequency luminance signal portions;
and
selecting means, operatively connected to said separating means, for evaluating a correlation relationship between points in different fields and for selecting one of said three higher frequency luminance signal portions in accordance with the correlation evaluation;
means, operatively connected to said first luminance signal development means and said selecting means, for combining said first luminance signal and the selected one of said higher frequency luminance signal portions, thereby producing a more accurate luminance signal.

2 more elements

Dependencies are inferred from the claim text.

Motion adaptive luminance signal and color signal separation filter

Life of this patent

Motion adaptive luminance signal and color signal separation filter

Life of this patent

Abstract

Claims46