JPH04255193A - Video signal processing circuit - Google Patents

Abstract

PURPOSE:To attain color reproduction with fidelity to an original signal with respect to the signal processing circuit in which video signals of different television system are synthesized in time series and the result is extracted as a video signal of a desired television system. CONSTITUTION:One video signal is selected among plural input video signals of different television systems by a selector 11. A common matrix circuit 12 multiplies a matrix multiplier coefficient for the same television system with a video signal from the selector 11 to generate three primary color signals.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing circuit, and more particularly to a video signal processing circuit for chronologically synthesizing video signals of different television systems and extracting a video signal of a desired television system.

[0002] In recent years, video signal processing technology using digital technology has become increasingly popular, and it has become possible to handle a plurality of video signals of different television systems on the same screen. FIG. 4 is a block diagram of an example of such a video processing system, in which color video signals of different television systems are input to terminals 1 and 2. There are various possible television systems that are different from each other, such as the NTSC system, PAL system, SECAM system, and high-definition television system (
(so-called high-definition), or by subsampling this high-definition television signal in a cycle of 4 fields and compressing the band to a maximum frequency of about 8 MHz.
USE (Multiple Sub-Nyquist
-sampling encoding) method, etc.

The color video signal of the second television system inputted to the terminal 2 is demodulated into a luminance signal and a color difference signal by the demodulation circuit 3, and then supplied to the scan conversion circuit 4, where it is input to the first television system. It is converted to the number of scanning lines of the system. on the other hand,
The color video signal of the first television system inputted to the terminal 1 is supplied to the demodulation circuit 5 and converted into a luminance signal and a color difference signal.

The video signal processing circuit 6 receives the luminance signal and color difference signal of the second television system from the scan conversion circuit 4;
The luminance signal and color difference signal of the first television system from the demodulation circuit 5 are respectively inputted, and the signals of both television systems are arbitrarily combined in time series, for example, in the form of three primary color signals, and the combination is performed. The signal is supplied to a cathode ray tube 7 for the first television system. As a result, the screen of the cathode ray tube 7 displays a color image based on the color video signal of the first television system inputted to the terminal 1 and a color image created using the color video signal of the second television system inputted to the terminal 2. An image with an embedded image will be displayed.

In such a video processing system, the video signal processing circuit 6 is required to have a circuit configuration that can reproduce colors as faithfully as possible to the original signal.

[0006]

2. Description of the Related Art FIG. 5 shows a block diagram of an example of a conventional video signal processing circuit. In the figure, video signals (specifically, color difference signals) of a first television system and a second television system are input to terminals 51 and 52, respectively, and the video signal of the first television system is input to terminals 51 and 52, respectively. The video signal of the second television system is input to the selector 53 and is converted into the video signal of the first television system by the signal converter 54 and then input to the selector 53 .

The selector 53 selects and outputs either the first video signal from the terminal 51 or the second video signal from the signal converter 54 at a desired switching timing according to a control signal input from the terminal 55. The signal is input to the matrix circuit 56 for television system No. 1. The first television system matrix circuit 56 processes the input video signal using matrix multiplication coefficients to produce red (R), green (G) and blue (B) signals.
The signal is converted into three primary color signals and input to a cathode ray tube (not shown). As a result, the first image based on the video signal of the first television system from the terminal 51 and the second image based on the video signal of the second television system from the terminal 52 are synthesized in chronological order. (superimposed)
You can get the image.

[0008] In this conventional example, by converting the video signal of the second television system into the first television system, the video signals of two different television systems are
The matrix circuit 56 for the first television system can be shared.

[0009]

However, in the above conventional circuit, in order to share the matrix circuit 56, the terminal 52
Since the video signal of the second television system inputted to the selector 53 is converted into the first television system by the signal converter 54, the output video signal of the signal converter 54 is
The color image based on the three primary color signals obtained through the three primary color signals and the matrix circuit 56 has a problem in that the fidelity to the original color of the color image based on the input video signal (original signal) of the terminal 52 is lost.

The present invention has been made in view of the above points, and
It is an object of the present invention to provide a video signal processing circuit that solves the above problems by using optimal matrix multiplication coefficients for each of a plurality of video signals of different television systems.

[0011]

[Means for Solving the Problems] FIG. 1 shows a diagram of the basic configuration of the present invention. In the figure, a selector 11 switches and selects any one input video signal from among a plurality of input video signals of different television systems at a desired time timing. Reference numeral 12 denotes a shared matrix circuit which stores matrix multiplication coefficients corresponding to each television system of a plurality of input video signals in advance, and applies matrix multiplication coefficients corresponding to the same television system as the video signal to the output video signal of the selector 11. Matrix calculation is performed using selected matrix multiplication coefficients to output three primary color signals.

0012

[Operation] In the present invention, the television system of the video signal taken out from the selector 11 is the same television system as that at the time of input. In addition, selector 1 is included in the shared matrix circuit.
Using the same control signal as that used in 1, a matrix multiplication coefficient dedicated to the same television system as that of the input video signal is selected to perform matrix calculation processing. Therefore, in the present invention, most of the circuits of the shared matrix circuit 12 can be shared to perform optimal matrix processing.

[0013]

Embodiment FIG. 2 shows a block diagram of a first embodiment of the present invention. This embodiment uses a luminance signal and two types of color difference signals R-Y and B-.
In the example where Y is processed in parallel, the first television system (
Hereinafter, for convenience, it will be abbreviated as "first method") luminance signals ■ and 2
The types of color difference signals R-Y■ and B-Y■ are each selected by the selector 2.
The luminance signal ■ of the second television system (hereinafter abbreviated as "second system" for convenience) and two types of color difference signals R-Y■ and B- are input to one of the input terminals 1, 22, and 23. Y
(2) are input to the other input terminals of the selectors 22, 21 and 23, respectively. In FIG. 2, selectors 21, 22, and 23 correspond to the selector 11, and the other circuit sections correspond to the shared matrix circuit 12.

The selectors 21, 22 and 23 are configured to simultaneously perform selection operations together with selectors 321 to 323 and 331 to 333, which will be described later, using the same selector signal (corresponding to the control signal in FIG. 1). The logical value of this select signal changes from high level to low level or from low level to high level at a desired time timing of image switching.

The color difference signal RY of the first method or the second method taken out from the selector 22 is sent to multipliers 241 and 242.
and 243, respectively. In addition, the selector 23
The output color difference signal R-Y of the selector 22 taken out from
The color difference signal B-Y of the same television system is sent to the multiplier 25.
1, 252 and 253, respectively.

On the other hand, 261 , 262 , 271 , 2
72 , 281 , 282 , 291 , 292 , 3
01, 302, 311, and 312 are memories, respectively, and the memories 261 and 271 store R signal generation matrix multiplication coefficients for the color difference signals (RY) and (BY) of the first method in advance, respectively. . Also memory 26
2 and 272 are color difference signals (R-Y) of the second method,
R signal generation matrix multiplication coefficients for (BY) are stored in advance.

Similarly, the memories 281 and 291 store G signals for the color difference signals (R-Y) and (B-Y) of the first system.
The signal generation matrix multiplication coefficients are stored in advance, respectively, and the G signal generation matrix multiplication coefficients for the color difference signals (R-Y) and (B-Y) of the second method are stored in advance in the memories 282 and 292, respectively. ing. In addition, the memories 301 and 311 store color difference signals (R-Y
), (B-Y) are stored in advance in the memories 302 and 31.
2 stores in advance B signal generation matrix multiplication coefficients for the color difference signals (R-Y) and (B-Y) of the second method.

The selector 321 selects the memories 261 and 2
Selectively output one of the matrix multiplication coefficients from 62,
The selector 331 selects and outputs one of the matrix multiplication coefficients from the memories 271 and 272. Similarly, selector 322 selects from memories 281 and 282, selector 332 selects from memories 291 and 292,
The selector 323 selects and outputs one of the matrix multiplication coefficients from the memories 301 and 302, and the selector 333 selects and outputs one of the matrix multiplication coefficients from the memories 311 and 312.

Multipliers 241, 242 and 243 multiply the color difference signals (RY) from selector 22 by matrix multiplication coefficients from selectors 321, 322 and 323, respectively. Multipliers 251, 252 and 25
3 are the color difference signals (B-Y) from the selector 23, respectively,
Multiply by matrix multiplication coefficients from selectors 331 , 332 and 333 .

The multiplied signals output from the multipliers 241 and 251 are respectively input to an adder 341, where they are added to the luminance signal from the selector 21 and converted into an R signal. Further, the multiplied signals output from both multipliers 242 and 252 are input to an adder 342, where they are added to the luminance signal from the selector 21 and converted into a G signal. Furthermore, both output multiplication signals of multipliers 243 and 253 are sent to adder 343.
Here, it is added to the luminance signal from the selector 21 and converted into a B signal.

Here, the luminance signal from the selector 21, the color difference signals (R-Y) and (B) from the selectors 22 and 23,
-Y) are respectively the first method, the selectors 321,
331 , 322 , 332 , 323 and 333
are memories 261, 271, 281, 291, 3
By selectively outputting the storage matrix multiplication coefficients of 01 and 311, adders 341, 342 and 34
3, the R signal, G signal, and B signal of the first system are respectively taken out.

On the other hand, the luminance signal from the selector 21 and the color difference signals (R-Y) and (B-
Y) is the second method, selectors 321 and 33
1, 322, 332, 323 and 333 are memories 262, 272, 282, 292, 302
By selectively outputting the storage matrix multiplication coefficients of and 312, the adders 341, 342 and 343
The R signal, G signal, and B signal of the second system are respectively taken out from.

The three primary color signals generated in this way are input to a display section (not shown) such as a cathode ray tube, where the color image of the second method is inserted into the color image of the first method (or the color image of the second method is inserted into the color image of the first method). Reverse) Display the image. Here, the display unit is preset to one of the first method and the second method, but if it is assumed that the display is set to the first method as an example, the memories 262, 272, 282, 292
, 302 and 312 are:
For the color difference signals (R-Y) and (B-Y) of the second method,
The values are set to the values that allow the most faithful color reproduction in the first method when generating the three primary color signals. In addition, the luminance signal of the second method ■,
The color difference signals R-Y■ and B-Y■ are sent to the selectors 21 and 22 after being converted to the same number of scanning lines as the number of scanning lines in the first method, respectively.
and 23.

As described above, according to this embodiment, the multiplier 2
41 to 243, 251 to 253 and adder 34
With a simple circuit configuration that shares 1 to 343, the first
Since matrix processing is performed without converting the color difference signals to either the first method or the second method, three primary color signals with faithful color reproducibility to the original signals can be obtained.

FIG. 3 shows a block diagram of a second embodiment of the present invention. In the figure, the same components as those in FIG. 2 are denoted by the same reference numerals, and the explanation thereof will be omitted. The embodiment shown in FIG. 3 is a color difference signal (R-
In the example when Y) and (B-Y) are input in dot sequence,
The brightness signals of the first method and the second method are respectively input to the selector 41, while the two types of color difference signals of the first method are input dot-sequentially to the selector 42, and the two types of color difference signals of the second method are input to the selector 42. Color difference signals are also input point-sequentially. Selectors 41 and 4
2, a luminance signal and a dot-sequential color difference signal of one of the first and second methods are respectively taken out. The point-sequential color difference signal taken out from the selector 42 is alternately converted into a color difference signal (R-
This is a time-series composite signal in which Y) and (B-Y) are arranged, and is supplied to one input terminal of multipliers 42, 422 and 463, which will be described later.

On the other hand, selectors 431 to 433, 44
Reference numerals 1 to 444 designate circuits for selectively outputting matrix multiplication coefficients, which are switched in synchronization with each other so as to alternately select two input signals every pixel data transmission period of the dot-sequential color difference signal. The selectors 431, 432, and 433 alternately select and output the matrix multiplication coefficient for the first method color difference signal (RY) and the matrix multiplication coefficient for the first method color difference signal (B−Y), respectively. 441, 442, and 443 alternately select and output matrix multiplication coefficients for the second method color difference signal (RY) and matrix multiplication coefficients for the second method color difference signal (BY), respectively.

Selectors 451, 452 and 453
uses the same select signals as the select signals of the selectors 41 and 42 to select and output the same television system matrix multiplication coefficients as the luminance signal and the dot-sequential color difference signal taken out from the selectors 41 and 42, and output them to the multipliers 461 and 46.
2 and 463. Therefore, during the period in which the luminance signal and point-sequential color difference signal of the first method are extracted from the selectors 41 and 42, the selectors 451, 452 and 453
selects and outputs the matrix multiplication coefficients of the first method from the selectors 431 , 432 , 433 , respectively, and during the period when the luminance signal and point-sequential color difference signal of the second method are taken out from the selectors 41 and 42 , the selectors 441 , 442
, 443 and selects and outputs the matrix multiplication coefficients of the second method.

The multipliers 461, 462, and 463 multiply the point-sequential color difference signals by the matrix multiplication coefficients, and the resulting signals are supplied to the adders 471, 472, and 473, and are used to divide the data between two adjacent pixel data. Addition is performed at That is, adders 471 and 472
, 473 adds the signal of the first pixel and the signal of the second pixel among the signals sequentially taken out from the multipliers 461 , 462 , 463 , and then adds the signal of the second pixel and the signal of the third pixel. The same addition operation is repeated thereafter. Adder 47 generated in this way
The output signals of 1, 472 and 473 are sent to the adder 341.
, 342 and 343, where it is added to the luminance signal from the selector 41 to form the R signal, G signal, and B signal of the first method or the second method.

In this embodiment, similarly to the first embodiment, the multiplier 4
61 to 463, adders 471 to 473 and 34
1 to 343, etc., it is possible to obtain three primary color signals that have undergone optimal matrix processing.

Note that the present invention is not limited to the above embodiments, and the input video signals may be three or more signals of different systems.

[0031]

As described above, according to the present invention, optimal matrix processing can be performed, so it is possible to obtain three primary color signals with color reproducibility that is more faithful to the original signal than in the past. It has the advantage of simplifying the circuit configuration because it can be shared.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention.

FIG. 2 is a configuration diagram of a first embodiment of the present invention.

FIG. 3 is a configuration diagram of a second embodiment of the present invention.

FIG. 4 is a block diagram of a video processing system to which the present invention can be applied.

FIG. 5 is a block diagram of an example of a conventional circuit.

[Explanation of symbols]

11 Selector 12 Shared matrix circuit 241 ~ 243 , 251 ~ 253 , 461 ~
463 multipliers 261 , 262 , 271 , 272 , 281 ,
282 , 291 , 292 , 301 , 302 ,
311 ,312 memory

Claims (3)

[Claims] 1. A selector (11) for switching and selecting any one input video signal among a plurality of input video signals of different television formats at a desired time timing; Matrix multiplication coefficients corresponding to the television system are stored respectively, and matrix calculation is performed on the video signal taken out from the selector (11) by selecting and using the matrix multiplication coefficient for the same television system as the video signal. 1. A video signal processing circuit comprising: a common matrix circuit (12) which performs the following and outputs three primary color signals. 2. Each of the plurality of input video signals includes a luminance signal and a color difference signal, and the shared matrix circuit (
12) is a storage circuit (261, 262, 271, 271,
272 , 281 , 282 , 291 , 292 ,
301, 302, 311, 312) and the storage circuit ((261, 262, 271, 272, 28) in synchronization with the switching timing of the selector (11).
1,282,291,292,301,30
2 , 311 , 312 ) to the selector (11)
Selection means (321 to 323,
331-333;431-433,441-
443, 451 to 453), and the selection means (32
1 ~ 323, 331 ~ 333; 431 ~ 433
, 441 to 443, 451 to 453) and the output color difference signal of the selector (11), respectively.
51 to 253; 461 to 463) and the multipliers (241 to 243, 251 to 253; 461
2. The video image according to claim 1, further comprising a signal generation circuit (341 to 343, 471 to 473) that generates and outputs three primary color signals from the output signal of the selector (11) and the output luminance signal of the selector (11). signal processing circuit. 3. The video signal processing circuit according to claim 1, wherein the plurality of input video signals are video signals that have been converted in advance to have the same number of scanning lines.