JPH0470182A - Luminance signal/chrominance signal separation device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a luminance signal/color signal separation (hereinafter referred to as Y/C separation) device used in video recorders and the like.

BACKGROUND OF THE INVENTION In recent years, with the demand for higher image quality in consumer video tape recorders, the importance of D and Y/C separation devices has increased.

A conventional Y/C separation device will be described below with reference to the drawings.

FIG. 3 is a block diagram showing a conventional Y/C separation device. In FIG. 3, l is the first delay circuit D, and the delay period is one horizontal period. 2 is a second delay circuit D,
The delay period is l horizontal periods. 3 is a first band pass filter (hereinafter referred to as BPF) that passes the color signal band. 4 is the second BPF D, which has the same characteristics as the first BPF. 5Fi 3rd BPF D, B with characteristic #″tK1
Equal to PF. 6 is the first selection circuit D, video signal! D
, E, and F are input, and a control signal is output according to the correlation of each signal. 7 is the first arithmetic circuit D, and the color signal output from the control signal 9IC from the first selection circuit is E, (E-
D)/2. Output either (EF)/2. 1O is a subtraction circuit D, which subtracts the color signal output G from the video signal B from the first Koinobu circuit 1.

The operation of the conventional Y/C separation apparatus constructed as described above will be explained below. First, the delayed video signal A is subjected to one horizontal period M in the first delay circuit 1. The signal ``+B'' output from the first itching circuit 1 is delayed by one horizontal period in the second delay circuit 2. Also, this input signal 8 is input to the first BPF 3 and the color signal band component is input to the first BPF 3. The signal BFi output from the first delay circuit l is inputted to the second BPF 4 IC, and the signal E from which the color signal band components are separated is output.
The signal +! output from the delay circuit 2 of fC is the third BP
The color signal band components inputted to F5 are separated and a signal F is output. Signals D, E, and F are input to the first selection circuit 6, respectively. In the first selection circuit 6, the color signal output is E, (E-D)/2,
A control signal indicating a color signal output selected from among the three (EF)/2 is output. The first arithmetic circuit 7 receives the signals D, E, and F, and selects E, (E− D)/2. Either (EF)/2 is output. Signal G is subtracted from signal B by subtraction circuit IO.

The output of the subtraction circuit 10 becomes a luminance signal output.

Problems to be Solved by the Invention However, the conventional configuration described above has a problem in that it contains components outside the band of the rfiBPF, such as chroma edge portions, and these components appear as dot interference in the luminance signal output.

The present invention is a book that solves the above-mentioned conventional problems, and its purpose is to provide a Y/C splitting apparatus that can perform more accurate Y/C splitting of salmon. Means for Solving the Problems The above-mentioned problems The ninth step to solve the problem is the Y/C separation device fj! of the present invention.
t is a first delay circuit that delays the input video signal A for n horizontal periods M (n is an integer), and a second delay circuit that delays the video signal B output from the first delay circuit for n horizontal periods. a delay circuit, a first band wL passing filter that passes the chrominance signal band of the video signal Jj+A, and a second band that passes the chrominance signal band of the image signal;B output from the first delay circuit;
a bandpass filter, a third bandpass filter that passes the color signal band of the video signal C output from the second delay circuit, and an output from the first bandpass filter. A video signal D outputted from the second bandpass filter, a video signal E outputted from the third bandpass filter, and a video signal F outputted from the third bandpass filter are input, and the video signals D, E, Depending on the correlation of F, 5 electric signal outputs are E, (E-D)/2. A first selection circuit that outputs all control signals indicating a color signal output selected from (E-F)/2, and a color signal output G according to the control signal output from the first selection circuit. E, (E-D)/2, (E-
F)/2. A first arithmetic circuit that outputs any one of the above video signals flA, c, D, F and color signal output G is inputted, and the correlation between the video signals A, C, D, F and the color signal output. Lebbe! V and B as the luminance signal output.
a second selection circuit that outputs a control signal indicating a luminance signal output selected from -G, (B+A)/2;
and a second arithmetic circuit that outputs one of BG(B+A)/2 as a luminance signal output according to the control signal output from the selection circuit.

Furthermore, the second selection circuit in the luminance signal/chrominance signal separation [iC] of the present invention selects a reference signal of a predetermined magnitude from K1. As K2, a fourth arithmetic circuit that subtracts the reference signal Kl from the absolute value of the difference between the video signal '8C and the video signal A and outputs whether the value subtracted by Kil is positive or negative, and the output of the third arithmetic circuit. a third delay circuit that delays the color signal by one horizontal period; a fifth arithmetic circuit that outputs whether the value obtained by subtracting the reference signal K2 from the absolute value of the color signal output G is positive or negative; The arithmetic circuit output and the third delay (b) path output are negative,
Outputting a control signal for selecting (B+A)/z as the brightness m-number output only when the fifth liquid calculation circuit output is positive, the third and fourth calculation circuit outputs, the third delay circuit output, Fifth operation Ijl! LV! - a logic circuit that outputs a control signal for selecting B-G as the luminance signal output when the output state is other than the above-mentioned state.

According to the configuration described in F, by adaptively switching the band of the comb characteristic portion of the luminance signal output to the entire band or the chrominance signal band vf, depending on the signal input to the second selection circuit, D, more accurate Y/C separation is performed, which makes it possible to reduce dot interference in the luminance signal output.

EXAMPLE Hereinafter, a Y/C/M division apparatus, which is one embodiment of the present invention, will be explained with reference to the drawings.

FIG. 1 is a block diagram of a Y/C separation device showing an embodiment of the present invention. Components that are the same as those of the conventional example are given the same reference numerals 8 and their explanations will be omitted.

In FIG. 1, at the input terminal of the second selection circuit 11,
An input terminal a to which a video signal A is input, a second ll delay circuit, a first BPF 3, a third BPF 5, and a first
The output terminal of the circuit 7 is connected to the second selection circuit 1.
The output terminal of 1 is connected to the second arithmetic circuit 12, which calculates the correlation between the video signals A, C, D, and F and the level/level of the color signal output G.
A control signal is output according to I/.

The second arithmetic circuit 121c has an input terminal a to which the video signal A is input, a first delay circuit 1, and a first arithmetic circuit 7.
and the output terminal of the second selection circuit 11 are connected, and according to the control signal output from the second selection circuit 11, the output terminal of the second arithmetic circuit 12 outputs the luminance signal B-G, (
The configuration is such that the b deviation of B+A)/2 is output.

With the above configuration, the operation will be explained below.

The video signal A input to the input terminal a is delayed by one horizontal period in the first delay circuit 1. The signal B output from the first delay circuit 1 is delayed by one horizontal period in the second delay circuit 2. Further, the signal Aii inputted to the input terminal alc and the signal inputted to the first BPF 3 from which the color signal band components are separated are outputted. The signal B output from the first delay circuit 1 is input to the 20th BPF 4 and has a color value Ji3'f
A signal E with the i-band component separated is output. moreover,
The signal C output from the second M iA 1m path 2 is input to the third BPF 5 K, where color signal band components are separated and signal F is output.

Signals D, E, and F are input to the first selection circuit 6. In the first S selection circuit 6, the color signal output is E, (E-D)/2, depending on the relationship of the input signals. (E-F)/2
A control signal indicating a color signal output selected from among the three is output. In the first calculation circuit i&7, mHD%E, F are input, and the color signal output G is set as E, (E
-D)/2 or (EF)/2 is output.

The second selection circuit 1 inputs the signals A, C, D, and F, and selects B- as the # signal output according to the correlation between the signals A, C, D, and F and the level of the color signal output G. G, (B
A control signal indicating the f4 degree signal output value selected from the two of +A)/2 is output. In the second calculation envelope 12, the signals A, B, and G are inputted and outputted from the second selection circuit 11.
In response to the control signal indicating the brightness signal output, the brightness signal
Either B-G or (B+A)/2 is output as a power output to switch the band of the combing part of the m signal signal output to the color signal band or to the entire band.

A circuit example of the second selection circuit 11 is shown in FIG. In FIG. 2, a subtracter 211C receives signals A and C, and its output terminal is connected to an absolute value circuit (ABS) 22, and a subtracter 23 receives signals D and F, and its output terminal is connected to an absolute value circuit (ABS) 22. g! A is definitely ff once ii! (ABS) 24. The output terminal of the absolute value circuit 22 is connected to a comparison circuit (
COMF) 25, and the edge of the absolute value circuit 240 is connected to a comparison circuit (COMF>26 IC).
The reference signals input to comparison circuits 25 and 26 are compared with 1, respectively. The output terminal of the comparator circuit 25 is connected to the input terminal of the kite circuit 28C1 via the third delay circuit 27, and also connected to another input terminal of the direct KAND circuit 2B.
The 8-input terminal of the comparator circuit 26 is connected to yet another input terminal of the melon circuit 28. Signal G is input to the absolute value circuit (ABS) 29, and the edge of the signal is connected to the comparison circuit (COMF).
30 VC board connected, comparator circuit 3LHC input base r
It is compared with 2 to the jl- signal. The output end of the comparison circuit 30 is connected to the input end of the AND circuit 2B via the NOT circuit 31, and the control output is output from the output end of the AND circuit 28.

According to the configuration described in E, first, the subtracter 21 subtracts the signal Aft from the signal C, and the subtracter 23 subtracts the signal Aft from the signal F. The absolute value circuit 22 calculates the absolute value t of the output of the subtracter 21.
It takes money. The absolute value circuit 24 takes the absolute value of the output of the subtracter 23. An absolute value circuit 29 takes the absolute value of the signal tG. A comparison circuit 25 subtracts and compares the output of the absolute value circuit 22 with a predetermined reference signal Kl, and if the output of the absolute value circuit 22 is small, a high level signal y is output, and if it is large, a low level signal Jl+ is output. Output. The comparator circuit 26 compares the output of the absolute value circuit 24 with a predetermined reference signal by subtracting 1 to obtain the absolute i! If the output of 1-circuit 2-fuku is small, it will output a high-level signal,
If it is large, a low level signal is output. Comparison circuit 30
Then, the output of the absolute value circuit 29 and a predetermined reference signal @ are subtracted by 2 and compared. If the output of the absolute value circuit 29 is small, a high level signal is output, and if it is large, a low level signal is output. do. The output of the comparison circuit 25 is the third ? The delay circuit 27 delays the signal by one horizontal period.

The output of comparator circuit 30 is inverted at NOT 1i21 path 31. Output 2 of comparison circuit 25, output 3 of comparison circuit 26
The output of the delay circuit 27 and the output of the NOT circuit 31 are input to the slow circuit 28, and the output of the AND circuit 28 becomes a control signal output. When the output of the AND circuit 28 is at a high level, (B+A)/2 is selected as the luminance signal output,
When the output of the paulownia circuit 1828 is at a low level, BG is selected as the luminance signal output.

In this way, by adaptively switching the band of the comb characteristic portion of the luminance signal output between the entire band and the BPF band, it is possible to reduce dot interference occurring at the output of the luminance signal.

Effects of the Invention As described above, according to the present invention, by adaptively switching the band of the comb characteristic portion of the 1lff signal output to the entire band or the BPF band, the dots appearing in the luminance signal output can be reduced. It is possible to obtain excellent effects such as reducing interference and realizing a more accurate Y/C separation device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a Y/C separation device according to an embodiment of the present invention, FIG. 2 is a block diagram of a second selection circuit in the Y/C separation device, and FIG. 3 is a conventional Y/C separation device. FIG. 2 is a block diagram of the device. 1... First delay circuit, 2... Second delay circuit, 3
...First BPF, 4...Second BPF, 5...
3rd BPF, 6... first selection circuit, 7... first
arithmetic circuit, 11... second selection circuit, 12... second arithmetic circuit, 21.23... subtracter, 22.24
．． 29...Absolute value circuit, 25, 26.30...Comparison circuit, 27...Third delay circuit, 28...Kite circuit,
31...NOT circuit. (℃ Q4 Town% Cats too *Sai University

Claims (1)

[Claims] 1. A first delay circuit that delays an input video signal A by n horizontal periods (n is an integer), and a video signal B output from the first delay circuit which is delayed by n horizontal periods. a second delay circuit that passes the color signal band of the video signal A; and a first delay circuit that passes the color signal band of the video signal A.
a second band pass filter that passes the color signal band of the video signal B output from the first delay circuit, and a color signal of the video signal C output from the second delay circuit. a third band-pass filter that passes a band, a video signal D output from the first band-pass filter, a video signal E output from the second band-pass filter, and a video signal E output from the third band-pass filter. A video signal F to be output is input, and E, (E-D)/
2. A first selection circuit that outputs a control signal indicating a color signal output selected from (E-F)/2; and a color signal output according to the control signal output from the first selection circuit. a first arithmetic circuit that outputs either E, (E-D)/2, or (E-F)/2 as G; and the video signals A, C, and D.
, F and color signal output G are input, and the video signal A,
a second selection circuit that outputs a control signal indicating a luminance signal output selected from B-G and (B+A)/2 as a luminance signal output according to the correlation between C, D, and F and the color signal output level; According to the control signal output from the second selection circuit, the luminance signal output is BG, (B+A)/
2. A luminance signal/chrominance signal separation device comprising: a second arithmetic circuit that outputs either one of the two signals. 2. The second selection circuit selects the video signal C and the video signal A using predetermined reference signals K1 and K2.
a third arithmetic circuit that outputs whether the value obtained by subtracting the reference signal K1 from the absolute value of the difference between the video signals F and D is positive or negative; and the value obtained by subtracting the reference signal K1 from the absolute value of the difference between the video signal F and the video signal D. a fourth arithmetic circuit that outputs positive or negative; a third delay circuit that delays the output of the third arithmetic circuit by one horizontal period; and a value obtained by subtracting the reference signal K2 from the absolute value of the color signal output G. a fifth arithmetic circuit that outputs positive or negative, outputs of the third and fourth arithmetic circuits, outputs of the third delay circuit are negative, and a luminance signal is generated only when the output of the fifth arithmetic circuit is positive; As output (B+A
)/2, and when the states of the third and fourth arithmetic circuit outputs, the third delay circuit output, and the fifth arithmetic circuit output are other than the above-mentioned states, a luminance signal is output. 2. The luminance signal/chrominance signal separation device according to claim 1, further comprising a logic circuit that outputs a control signal for selecting BG as an output.