JPS62154995A - Y/c separating device with contour emphasizing function - Google Patents

Abstract

PURPOSE:To obtain an image with high definition by generating a contour emphasized signal by a contour emphasizing part of simple constitution by utilizing a signal generated in a Y/C separating device, and adding the signal to a separated Y signal. CONSTITUTION:The output of the adder 14 in a Y/C separating circuit 10 is four times as large as a C signal when signals ln+1, ln, and ln-1 are completely correlative. If, however, the correlation is lost and adjacent scanning lines of an image are different in intensity, outputs 14A and 14B of the adder 14 contain the difference signal of the Y signal in addition to the C signal. For the purpose, the difference signal corresponding to differential characteristics is utilized positively to emphasize the vertical contour, and the cutoff frequency of a low-pass filter 101 is so determined as to remove a nearby frequency band including the C signal. Therefore, its output becomes DELTAY corresponding to the differential quantity of Y and a vertical contour emphasized signal is obtained and made by a level adjusting coefficient multiplier 103 into KDELTAY, which is sent to an adder 105. The coefficient K is determined by a coefficient setter 104.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for converting a luminance signal (
The present invention relates to a Y/C separation device that separates Y (hereinafter referred to as F) and a color signal (hereinafter referred to as C signal), and particularly relates to one having a vertical contour function.

[Conventional technology]

The sharpness of a television image is one of the factors that determines the image quality, and for this reason, various means have been used to perform edge compensation or enhancement. In the case of water 1 and ring tIX emphasis, the high frequency components of the luminance signal extracted by a high-pass filter are superimposed on the original signal, but in the case of vertical contour emphasis, the circuit 1j and 5 components are It becomes 11 things.

Figure 3 is an example of this, with Y7 separated by Y/C separation circuit 1.
．． 1 signal to the cascaded 1 if delay completion 2, 3, I
The output Y□1 signal of the H delay element 3 is added to the output Y□1 signal by the q adder 4, and then multiplied by 1!2 by the coefficient multiplier 5 to obtain the 2.111 arithmetic average Y1 signal.

A subtracter 6 takes the difference from the signal. This difference ΔY1 signal is used as a vertical contour emphasis signal, and is multiplied by a coefficient K as appropriate by a coefficient unit 7 to obtain I(ΔY4, Y,).

Add to signal.

The above contour is emphasized (Yn++(△Yo)i, 1-3
and C1. which is the output of the Y/C separation circuit 1. +(No. 1i is set to 1, and the C7 signal delayed by H delay element 9 is input to the subsequent matrix circuit. The above circuit requires three IH delay elements and an adder, subtracter, coefficient unit, etc. Even if it is provided to improve image quality, an increase in cost cannot be avoided.

[Problem that the invention seeks to solve]

By the way, as a Y/C separation method, a method of separating video signals on the time axis by utilizing the correlation between adjacent scanning lines (hereinafter referred to as a correlation separation method) is well known. As a circuit configuration of this method, IH delay elements are connected in 'lftkM,
There is a method that combines the signals of each part of this string.

Since the vertical contour emphasizing circuit also utilizes the cascade connection of IH delay elements, if the main parts of the Y/C separation circuit can be used as is and have the vertical contour emphasizing function, the above-mentioned vertical contour enhancement circuit can be improved. The disadvantages of a cost amplifier in which a separate circuit is provided for contour enhancement can be avoided.

The object of the present invention was to solve the above-mentioned problems, and to provide a device in which a vertical contour enhancement function is added to a Y/C separation device.

[Failure to solve the problem]

The device of the present invention is located in a neighboring country of Video Telecommunications-J;
l:I! y 7 (
In the 11 device, 3 scanning line signals 7! . . ,, /
! n, /! , , is included in the separation means for taking the difference between , , and the output e of the filter 1 (1γ).
+>Apn''-7!-1) ;21'l.

Each of them is separately put into a low-pass filter.
Alternatively, the output of the adder of the l1ii signal included in the separating means is passed through a low-pass filter B, and an edge-enhanced signal is created, and 1/-, lil! ,1
The Y signal of the Y/C separator is superimposed through the integral coefficient filter. It was designed so that

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. As a Y/C separation device, any type of device can be used as long as it uses two X1iY identical IH delay elements and uses the correlation between three adjacent scanning lines, or it includes a part that takes a correlation. It can be any format.

Typical correlation separation method circuit diagram 1, I (l
It is as shown in . This circuit is called a 2H type, and uses two delay elements 11a and Ilb to separate Y and C signals by combining signals at each node. The midpoint is the current signal β7, and the previous signal 1n-1 is subtracted by the subtracter 13.
If done with b, j2. =Y, +C,.

'--+=Yn-+ C-+ (a negative sign is added considering the phase of C), β7-βn-1= (Y, l
-yn-+) +C,,10□1, signal 7!7 and signal! , -1, this difference signal is approximately 2
C. Similarly, the subtracter 13a (βn-l1n
+1) difference signal also becomes approximately 2C. Subtractor 13a, 1
Adder 14 adds the outputs of 3b, and multiplier 15 adds 1/
Multiplying by 4 yields the C signal. Further, when the C signal is subtracted from the signal 17 by the subtracter 16, the Y signal is obtained.

In the Y/C separation circuit 10, an edge enhancement section 100 (11
Add. Contour enhancement unit 100 (11 is a low-pass filter 101.Level adjustment coefficient unit 103.Coefficient setter 10
4. It is composed of an adder 105.

The operation of the contour emphasizing unit 100 (11) will be explained below.The output of the adder 14 in the Y/C separation circuit 10 is the signal A, .
l・), it becomes four times as large as the C signal. However, if the intensity of adjacent scanning lines is different in an image with broken correlation,
The outputs 14A and 1411 of the adder 14 include a difference signal of the Y signal in addition to C(8).The present invention uses this difference signal corresponding to the differential characteristic to The purpose is to emphasize vertical contours by ΔY, which corresponds to , becomes a vertical contour emphasizing signal.

This signal is sent to the adder 105 as ΔY by the adjustment coefficient unit 103. A coefficient setter 107 is used for the coefficient.
1.

As described above, j=1 is added to the Y/C separation circuit 10 by a simple axial contour emphasizing section 100 (1), and an appropriate signal in the Y/C separation circuit 10 is taken. , ring 91 - emphasis can be made. Note that even if the circuit configuration is such that the multiplier 15 is included in the adder 14, it is only necessary to change the coefficients appropriately using the coefficient setter 104.

Next, as another Y/C separation device, a case where the present invention is applied to Japanese Patent Application No. 60-2325281 "Y/C separation device for color television signals" of which the present inventor is one of the co-inventors will be described. This device consists of a Y/C separation circuit using a correlation separation method using temporal correlation, a Y/C separation circuit using a frequency separation method using a single frequency filter, and each of these Y/C separation circuits.
It has a combining means for weighting and combining each of the luminance signal and color signal received from the separation circuit, and means for detecting a vertical change component and changing the weighting according to the magnitude of the detected component. It is.

Second, 1 applies the present invention to the above-mentioned separation device, and the contour enhancement unit 1
00+21 is added. FIG.

10 is a correlation separation type Y/C separation circuit, which is the same as the circuit shown in FIG. 20 is a Y/C separation circuit of frequency separation type, and the Y+, C+ and Yz, Cz signals output from both Y/C separation circuits 10.20 are sent to a synthesis circuit 30.
The Y and C signals are weighted and combined. Coefficient circuit 3 that weights the synthesis circuit 30
Coefficients 1 to 34 are determined by the synthesis control circuit 70. The input to the synthesis control circuit 70 is the color signal horizontal component detection circuit 40. Shining 1. ph l;'+ "j Horizontal component detection circuit 50. This is the output of the vertical component detection circuit (position). Each of the above circuits 40.
50. 6 (Due to the combination of the output sizes of l,
Y l , CI (,@-No. 1 and Y,.

By changing the mixing ratio of C2 signal, 1-1 scalar, 17
Appropriately suppress tocole.

The contour emphasizing section 100 +21 is φa91X strong 3 in FIG.
+! , + +'il+ +00 (almost the same as 1, 1, but adder 102 is added instead of 'yi H\return c:). Adder 102 The human power is the brightness f1 1υ low frequency 1111 j0 filter 51 on the input side of the water horizontal bone detection circuit 50.
.degree.52, respectively. The word input to the input filter 51.52 is "Ylo") i
kl [Output 1 of subtraction circuits 13b and 13a in circuit 10
．． −, %; In Figure 1, the subtraction circuit +3b, M
ll100 output Adder 14 adds the output and imports the output No. 11 >H';,ly・! In contrast, in FIG.
The outputs of a are respectively low-pass filters 51 and 52-C.
After removing the color signal components, the adder 102 adds them. Therefore, they are completely identical in operation.

However, there is an advantage that the low-pass filters 51 and 52 are also used for contour enhancement.

〔Effect of the invention〕

As explained in detail below, in a Y/C separation device that includes separation means that utilizes the correlation between three scanning lines, the Y/C
By using the signal generated in the separation device to create an edge enhancement signal in an edge enhancement section with a simple configuration and adding it to the separated Y signal, a highly sharp image can be obtained.

[Brief explanation of drawings]

1 and 2 are circuit block diagrams showing an embodiment of the present invention, and FIG. 3 is a diagram showing a circuit in which an edge enhancement circuit is provided separately from a Y/C separation device. 10-Y/C separation circuit (correlation separation method), 11 a,
1 l b, -4H delay element, 13a, 13b, 1
6 - subtractor, 14 - adder, 20 - Y/C separation circuit (frequency separation method), 30 - synthesis circuit, 50 - luminance signal horizontal component detection circuit, 51.52 - low pass filter, 100 (1) , 100 (21--Contour enhancement unit, 101-Low pass filter, 102-Adder 1γ unit, 103-Level adjustment coefficient unit, 10t---Coefficient setter, 105-Adder.

Claims (1)

[Claims] In a Y/C separation device including separation means that utilizes correlation between three adjacent scanning lines of a video signal, three scanning line signals l_n
A difference signal (l_n
-l_n_+_1) and (l_n-l_n_-_1) separately through low-pass filters, or
Alternatively, the output of the adder of the difference signal included in the separation means is passed through a low-pass filter to create an edge-enhanced signal, which is superimposed on the Y signal of the Y/C separation device via a level adjustment coefficient device. A Y/C separation device equipped with an edge enhancement function.