JPH01109891A - Digital picture transmission system - Google Patents

Abstract

PURPOSE:To simply adjust a matrix operating part and a dematrix operating part by executing a matrix operation by a digital signal and thereby, changing the combination of the coefficients of the matrix operation according to an external control signal. CONSTITUTION:The analog input signals R, G, B of a transmission side pass through low pass filters 10-12, are converted to the digital signals respectively in A/D converters 13-15, respectively matrix operated in a matrix operating part 16 and thereafter outputted as the three digital signals Y, CW, CN. At this time, the combination of the coefficients of the matrix operation is executed according to the external matrix control signal by a matrix control part 17. In a reception side, the digital signals of Y, CW, CN are separated again in a demultiplexer part 22. A dematrix control part 24 changes the combination of the coefficients of the matrix operation of a dematrix operating part 23 according to an external dematrix control signal to convert Y, CW, CN to R, G, B by this combination.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a system for converting an analog video signal into a digital signal and transmitting the converted signal.

2. Description of the Related Art As a conventional digital image transmission system, for example, a system as shown in FIG. 3 is used.

FIG. 3 shows a block diagram of this conventional digital image transmission system. Reference numeral 40 denotes a matrix calculation unit that performs matrix calculations on three analog input signals and outputs the results as three analog signals; 41 to 43; is a low-pass filter, 44 to 46 are A/D converters, 4
7 is a multiplexer unit that multiplexes the digital outputs of the A/D converters 44 to 46; 48 is a multiplexer unit 47;
49 is a transmission line for transmitting the signal from the transmitter 48; 50 is a receiver for receiving the signal transmitted by the transmission line 49; 51
is a demultiplexer section that separates the output from the receiver 50 into three digital signals again; 52-53 are D/A converters; 54-56 are low-pass filters; 57 is a matrix calculation section 50 that converts the analog signals from the low-pass filters 54-56 into This is a dematrix calculation unit that performs an inverse matrix calculation of the matrix calculation performed in , and outputs the results as three analog signals.

In the conventional digital image transmission system configured as described above, on the transmitting side, a matrix calculation section 40 performs matrix calculations on three analog human input signals, and then passes the respective outputs through low-pass filters 44 to 46 to convert them into digital signals. multiplexed and transmitted. The received signal separated by the demultiplexer on the receiving side is sent to each D/
After being returned to analog signals by A converters 52 to 53 and passing through low-pass filters 54 to 56, a dematrix calculation unit 57 performs an inverse matrix calculation of the matrix calculation performed by matrix calculation unit 40 and outputs the result.

Problems to be Solved by the Invention However, in a digital image transmission system configured as described above, matrix calculations and inverse matrix calculations in the matrix calculation section 40 and dematrix calculation section 57 are usually performed by dividing each analog signal using resistors. This is achieved by adding them together. In this method, the coefficients of the matrix calculation are determined by the values of the above-mentioned voltage dividing resistors, so adjustment is very easy, and the combination of coefficients can only be changed by replacing the resistors with the resistance values corresponding to the coefficients. For the same reason, it is also necessary to consider the effect of changes in resistance value over time. Moreover, once the coefficients of the matrix calculation are determined, it is difficult to change them later or to change the combination of the coefficients of the matrix calculation according to the combination of human input signals (for example, three primary colors, a luminance signal, and two color difference signals). It had some problems.

In view of the above, an object of the present invention is to provide a digital image transmission system in which the matrix calculation section and the dematrix calculation section can be easily adjusted and the combination of matrix calculation coefficients can be changed depending on the type of human input signal. shall be.

Means for Solving the Problems The present invention includes three low-pass filters, three A/D converters connected to each of the low-pass filters,
A matrix calculation unit that outputs three digital signals after performing matrix calculations on each of the three digital signal outputs from the A/D converter, and a matrix calculation coefficient of the matrix calculation unit that changes to another combination according to an external matrix control signal. a matrix control section that multiplexes the three digital signals from the matrix calculation section, a transmitter that transmits the signal from the multiplexer section, a transmission line that transmits the signal from the transmitter, and a transmission line that transmits the signal from the transmitter. A receiver that receives a signal, a demultiplexer section that separates the output from the receiver into three digital signals again, and a dematrix operation section that performs a matrix operation on the three digital signals from the demultiplexer section and outputs three digital signals. , a dematrix control unit that changes the combination of coefficients for matrix calculation in the dematrix calculation unit according to an external dematrix control signal, and three D/A units that convert the three digital signals from the dematrix calculation unit into analog signals. converter and D
A digital image transmission system comprising three low-pass filters each connected to a /A converter.

Effect of the Invention With the above-described configuration, the present invention performs matrix calculations using digital signals, and can change the matching of the coefficients of the matrix calculations using the matrix control section and the dematrix control section in accordance with external control signals.

Embodiment FIG. 1 shows a block diagram of a digital image transmission system in the first embodiment of the present invention. 2 In FIG.
/D converter, 16 is A/D controller 13-15
A matrix calculation unit that outputs three digital signals after performing matrix calculations on the three digital signal outputs from the matrix calculation unit 17, and a matrix 17 that changes the coefficients of the matrix calculation of the matrix calculation unit 16 to another combination according to an external matrix control signal. Control unit, 1
8 is a multiplexer unit that multiplexes the three digital signals from the matrix calculation unit 16, and 19 is a multiplexer unit! 20 is a transmission line that transmits the signal from transmission line 19, 21 is a receiver that receives the signal transmitted by the transmission line 20, and 22 is the output from the receiver 21 which is converted into three digital signals again. 23 is a dematrix calculation unit that performs matrix calculations on the signals from the demultiplexer unit 22 and outputs them as three digital signals;
24 is a dematrix control unit that changes the combination of coefficients for matrix calculation in the dematrix calculation unit 23 according to a dematrix control signal from the outside; 25 to 27 are D that convert digital signals from the dematrix calculation unit 23 into analog signals; /A converter, 28 to 30 are low pass filters.

The operation of the digital image transmission system of this embodiment configured as described above will be described below. for example,
Consider a case where the analog human input signals on the transmitting side are R, G, and B, and the analog output signals on the receiving side also need to be R, G, and B. R, G, passed through the low-pass filter 10-12,
The B analog signals are converted into digital signals by A/D converters 13 to 15, respectively. Then, the R, G, and B digital signal outputs from the A/D converters 13 to 15 are subjected to matrix calculations in a matrix calculation section 16, and then converted into three digital signals (for example, a luminance signal Y and two color difference signals CIJ and CN). is output as At this time, the combination of coefficients of the matrix calculation of the matrix calculation unit 16 is determined by the matrix control unit 17 according to the matrix control signal from the outside.
It is a combination that converts into Y, Cu, and CN.

The Y, Cu, and CH digital signals from the matrix calculation section 16 are multiplexed by the multiplexer section 18 and transmitted from the transmitter 19. Signal 1 transmitted through the transmission path 20 is received by a receiver 21 and separated again into Y, CW, and CN digital signals by a demultiplexer section 22. The dematrix control unit 24 changes the combination of coefficients of the matrix calculation of the dematrix calculation unit 23 in accordance with the dematrix control signal from the outside, and performs a matching to convert Y, Cu, CN into R, G, B, and this coefficient With the combination of
, B digital signals are output. These outputs are converted from digital signals to analog signals by D/A converters 25 to 27, respectively, and then sent to low pass filters 28 to 30.
The R, C, and H of the halo are output as analog signals.

As described above, according to this embodiment, the matrix calculation unit I
By performing the matrix calculations in 6 and the dematrix calculation section 23 using digital signals, almost no adjustment is required, and the influence of aging of circuit elements can be reduced. In addition, in this embodiment, analog input/output signals are R, C;
B, but the analog human input signal on the transmitting side and the analog output signal on the receiving side are Y, Cw, CN or C+,
Even a combination of Co, etc. can be easily handled without changing the circuit by changing the control signal from the outside.

FIG. 2 is a block diagram of a digital image transmission system showing a second embodiment of the present invention. In this figure, elements common to those in FIG. 1 are given the same numbers.

The difference from the configuration shown in FIG. 1 is that the matrix control section 17 changes the coefficients of the matrix operation of the matrix operation section 16 to another combination according to the external matrix control signal, and also thins out samples from the digital output of the matrix operation section 16. The multiplexer section 18 multiplexes the three digital signals from the matrix calculation section 16, the combination code and thinning code from the matrix control section 17, and other signals from the outside, and outputs the combination code and thinning code. 22 separates the output from the receiver 21 again into three digital signals, a combination code, a thinning code, and other signals, and a dematrix controller 24 separates the output from the receiver 21 into three digital signals, a combination code, a thinning code, and other signals.
The combination of coefficients of the matrix calculation of the dematrix calculation unit 23 is changed according to the combination code separated by the combination code and the dematrix control signal from the outside, and the samples that have been thinned out and not transmitted by the matrix control unit 17 according to the jump code are It has an interpolation function.

The operation of the digital image transmission system of the second embodiment configured as described above will be explained below. For example, consider a case where the analog human input signal on the transmitting side is R, C;, B, and the analog output signal on the receiving side also needs R, C, B.

In this system, R, C, B
Assume that digital output is performed as is. It is also assumed that the matrix control section 17 does not thin out samples from any of the digital outputs of the matrix calculation section 16 because the amount of other signals inputted to the multiplexer section 18 from the outside is small. By setting in this way, it is possible to sufficiently use the band of the transmission path to transmit high-quality images. At this time, the matrix control unit 17 must not thin out the combination code and sample indicating that the matrix calculation unit 16 inputs the R, G, and B digital signals and outputs the R, G, and B digital signals. A thinning code indicating . This patching code and thinning code are processed by the multiplexer section 18.
, B are multiplexed and transmitted. The demultiplexer section 22 separates the transmitted signal into R, G, and H digital signals, a dark blue matching code, and a thinning code.
The dematrix control unit 24 controls the combination of coefficients of the dematrix calculation unit 23 according to an external dematrix control signal requesting R, G, and B outputs and a combination code.
This is a combination of manually inputting G and B digital signals and outputting R, G and B digital signals. As described above, a system is obtained in which the analog human input signals on the transmitting side are R, G, and B, and the analog output signals on the receiving side are also R, G, and B.

However, suppose that it becomes necessary to increase the amount of other external signals, and the occupancy rate of the transmission path for the video signal that has been transmitted thus far has to be reduced. At this time, if samples are thinned out from the R, G, and B digital outputs on the transmitting side and the thinned out samples are interpolated on the receiving side, the required transmission band can be reduced and the occupancy rate of the transmission path can be lowered. However, rather than this method, the R, G, and B digital signals are converted into Y, CIJ, and CN by matrix calculation,
The samples of Y are not thinned out, only the samples of CIl and CN are thinned out, and the thinned out samples of C u and CN are interpolated on the receiving side, and the samples of Y.

Inverse matrix calculation is performed from Cu and CN and R and G are calculated again.
, converting to B can prevent deterioration in image quality.

Therefore, the matrix control signal is changed so that the combination of coefficients of the matrix calculation section 16 converts the R, G, and B digital signals into Y, CIJ, and CN.

Then, the matrix control unit 17 selects CW, C out of the Y, Cw, and CN outputs of the matrix calculation unit 16.
Only N samples are thinned out and output to the multiplexer section 18, and the coefficients of the matrix operation in the matrix operation section 1G are R, C;, B is Y, CIJ, C
Combination code indicating that the combination is to be converted to N and C
w and a thinning code indicating that the sample of C6 is thinned out to the multiplexer unit 18. This combination code and the thinned-out code are multiplexed with the digital signals of Y and the thinned-out C u and CN in the multiplexer section 18 and transmitted. The demultiplexer section 22 separates the transmitted signal into Y, Cu, and CN digital signals, a combination code, and a thinning code.

Then, the dematrix control unit 24 interpolates the thinned samples of the digital signals of CIJ and CN from the transmitted samples according to the thinning code, and at the same time
According to the dematrix control signal from the outside requesting G, B output and the combination code, the combination of coefficients of the dematrix calculation unit 23 is manually performed using the digital signals of Y, C&I, and CN to generate the digital signals of R, C;, and H. Use the combination when outputting. With the above, the analog human input signal on the transmitting side is R, G, B, and the analog output signal on the receiving side is also R, G.
, B, and a system with a reduced transmission band is obtained.

As described above, according to this embodiment, by transmitting the combination code and the thinning code, the type of video signal to be transmitted is switched in real time, and the occupancy rate of the transmission path is changed according to the usage status of the transmission path. Since signals can be transmitted, the transmission path can be used effectively.

As described in detail, according to the present invention, there is almost no need to adjust matrix operations, there is little influence from aging of circuit elements, and the external control signal can be changed in response to changes in the type of human output signal. This can be easily done without changing the circuit. In addition, by transmitting the combination code and thinning code, the type of video signal to be transmitted can be switched in real time and the transmission path occupancy rate of the video signal to be transmitted can be changed, so the transmission path can be used effectively. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a digital image transmission system according to an embodiment of the present invention, FIG. 2 is a block diagram of the same embodiment, and FIG. 3 is a block diagram of a conventional digital image transmission system. lO~12...Low pass filter, 13~15...
A/D converter, 16... Matrix calculation section, 1
7... Matrix control section, 18... Multiplexer section, 19... Transmitter, 20... Transmission line,
21... Receiver, 22... Demultiplexer section,
23... Dematrix calculation unit, 24... Dematrix control unit, 25-27... D/A converter, 2
8-30...Low-pass filter, 40...Matrix operation section, 41-43...Low-pass filter, 44
~46... A/D converter, 47... Multiplexer section, 48... Transmitter, 49... Transmission line, 50... Receiver, 51... Demultiplexer section, 52-54... D/A converter, 55-57...
-Low pass filter, 58... Dematrix calculation section.

Claims (2)

[Claims] (1) three low-pass filters and three A/D converters connected to each of the low-pass filters;
A matrix calculation unit that outputs three digital signals after performing matrix calculations on the three digital signal outputs from the A/D converter, and a different combination of matrix calculation coefficients of the matrix calculation unit in accordance with an external matrix control signal. a matrix control unit that changes the three digital signals from the matrix calculation unit, a multiplexer unit that multiplexes the three digital signals from the matrix calculation unit, a transmitter that transmits the signal from the multiplexer unit, and a transmission line that transmits the signal from the transmitter;
a receiver that receives the signal transmitted through the transmission path; a demultiplexer that separates the output from the receiver into three digital signals again; and a demultiplexer that performs matrix operation on the three digital signals from the demultiplexer and converts them into three digital signals. a dematrix calculation unit that outputs a signal; a dematrix control unit that changes a combination of coefficients for matrix calculation in the dematrix calculation unit according to an external dematrix control signal; and three digital signals from the dematrix calculation unit. What is claimed is: 1. A digital image transmission system comprising: three D/A converters for converting the D/A converters into analog signals; and three low-pass filters respectively connected to the D/A converters. (2) The matrix control section changes the coefficients of the matrix operation of the matrix operation section to another combination according to the matrix control signal from the outside, and transfers one sample out of all the samples of each digital output of the matrix operation section to the multiplexer. The multiplexer unit The three digital signals from the matrix calculation unit, the combination code and thinning code from the matrix control unit, and other external signals are multiplexed, and the demultiplexer unit converts the output from the receiver into three digital signals again. The combination code, thinning code, and other signals are separated, and the dematrix control unit changes the combination of coefficients of the matrix calculation in the dematrix calculation unit according to the external dematrix control signal and the combination code separated by the demultiplexer unit. 2. The digital image transmission system according to claim 1, wherein the digital image transmission system has a function of interpolating samples that have been thinned out and not transmitted by the matrix control unit according to a thinning code from the transmitted samples.