SU1734239A1 - Measurement method of influence of chromaticity signal on brightness signal in television path - Google Patents

Abstract

This invention relates to a television measurement technique. The purpose of the invention is to improve accuracy. The method of determining the effect of a chroma signal on the luminance signal of a television path is that it generates a low frequency (A (t)) radio frequency B (t) sin wt component of the measurement signal, where B (t) is the radio pulse envelope, t is the time , y - the angular frequency, form the measuring signal in the form Uo (t) A (t) + B (t), additionally form the measuring signal in the form Uc (t) A (t) + B (t) sin (a) l + l) pass both signals through the television path, the instantaneous values of each of the two measurement signals are measured at the output of the path in Ui (t) and U2 (t) and the instantaneous values of the low-frequency signal are determined at each time instant using the formula A (t) (1/2) Ui (t) + U2 (t), the instantaneous values of the signal A (t ) at the characteristic points at which the desired parameter is determined. Form two more measurement signals in the form of Uk (t) A (t) + A (t) + B (t) sin ("(t) + South / 2) K 1.3), pass them through the television channel, at the output the path measures the instantaneous values of each of the four measurement signals and determines the instantaneous values of the low-frequency signal at each time instant t using the formula A (t) (I / 4) U0 (t) + Ui (t) + Ua (t) + Us ( t}. 1 з п f-ly, 6 ill. Ate with

Description

The invention relates to a television measurement technique and can be used to create enhanced accuracy television complexes for measuring the influence of a chroma signal on the luminance signal of a television path.

The purpose of the invention is to improve accuracy.

FIG. Figure 1 shows a generalized structural electrical circuit of a device for determining the influence of a chroma signal on a luminance signal; in fig. 2 is a structural electrical circuit of the output block of synchronization and interface with the television

(TV) tract; in fig. 3 is a structural electrical circuit of the input block of synchronization and interfacing with the TV path; Fig 4, 5 - time diagrams of signals Ui (t), U2 (t), respectively; in fig. 6 is a timing diagram of the recovered low frequency component of the measurement signal.

The method of determining the influence of the цвет color signal on the luminance signal is as follows: generate a low frequency — A (t) and radio pulse — B (t) sin al components of the measurement signal, where B (t) is the radio pulse envelope VJ

soh

00

Yu

t, time, co is the angular frequency, form the measuring signal in the form

U0 (t) A (t) + B (t) sinu) t

additionally form the measuring signal in the form

U2 (t) A (t) + B (t) sin (al +),

signals UK (t), k 0.2 are passed through the television path, the instantaneous values of each of the two measuring signals U0 (t) and U2 (t) are determined at the output of the path and the instantaneous values of the low-frequency signal are determined at each time t by formula

A (t) (t) + U2 (t) l (1)

The instantaneous values of the signal A (t) are measured at characteristic points that determine the desired parameter.

In addition, a method for determining the effect of a luminance signal on a chrominance signal is to additionally form measurement signals in the form of

Uk (t) A (t) + B (t) sin (ate fk / 2), (k 1,3), pass them through the television path, the instantaneous values of each of the four measurement signals are measured at the output of the path, and instantaneous values of the low-frequency signal at each time instant t according to the formula

A (t) 1 (t) + Ui (t) + U2 (t) + U3 (t) j (2)

A device that implements a method for determining the effect of a chrominance signal on the luminance signal of a television path (Fig. 1) contains: a block 1 of computing the components of the television measuring signals, the first multiplexer 2, the first 3, the second 4, the third 5 and the fourth 6 memory blocks, the output block 7 synchronization, television path 8. Synchronization input unit 9, zone generator 10, second multiplexer 11, fifth 12, sixth 13, seventh 14 and eighth 15 memory blocks, computed block 16, control block 17.

The output block 7 of synchronization and conjugation (FIG. 2) contains an address counter 18, a pulse shaper 19, a digital-to-analog converter (D / A converter) 20, a clock generator 21, a first spectrum conversion unit 22.

The synchronization and coupling input unit 9 (FIG. 3) comprises a second spectrum conversion unit 23 and an analog-to-digital converter (ADC) 24.

A device for carrying out the method for determining the effect of a signal operates as follows.

Block 1 of the calculation of the television measuring channel components (Fig. 1) calculates the values of the samples of the four phases of the measuring signal (Fig. 4, 5, 6) with the sampling interval satisfying the conditions of the Kotelnikov theorem, and writes them into blocks 3-6 memory, address code, and other signals needed to control the first, second, and third

5 blocks 3-6 of memory, are generated synchronously with the calculated samples of the signal of the block 1 of the calculation of the component of the measuring television signals and through the first multiplexer 2 determine the number

The 0 cells and the number of the memory block where the value of the corresponding sample is to be written, and controls the operation of the blocks 3-6 of the memory.

The values of the samples of other components, in

5 including the synchronization signal, is calculated by the computing unit 1 component of the television signals and recorded in the memory blocks in the same way. Thus, the digital equivalent of the TV frame is formed, the state of the first multiplexer 2 is set from the output of the computing unit 1 of the measuring signals. After recording the signals in blocks 3-6, memory, multiplexer 2 switches the hook, which is

The 5 inputs of the memory blocks 12, 13, 14 begin to receive the code of the current address of the TV measuring signal and other signals necessary for controlling the memory blocks from the output block 7 of synchronization and interface with the TV path. As a result, at the input of this block, signals are alternately alternating in cs, which together with the synchronization signals and other components of the TV measuring signals read from these

5 of the memory blocks, the digital equivalent of the TV measurement signal, which from the output of the synchronization unit 7 is fed to the input of the TV path 8 in a form suitable for transmission along the DUT path. The output signal from the TV path

0 8 is fed to the input block 9 of synchronization and interface with the TV path 8, from the output of which the received signals are alternately recorded in blocks 12-15 of memory. The code of the current address of these signals and others

5, the signals necessary for controlling the memory blocks 12-15 are generated in the zone generator 10 and fed to the memory blocks 12-15 through the second multiplexer 11, which is set in its state by a signal from the output of the control unit 17.

This signal is generated as follows. The parallel binary code of the current address of the TV measuring signal from the generator output 10 zones goes to the control block 17, where the codes determining the numbers of the first and last sample of the TV frame section where the measured component of the TV measuring signal is located are output from the computing block 16 . When the code of the current address coincides with the codes of the selected first and last samples, two pulses are sequentially formed, with the help of which a square pulse is formed corresponding to the boundaries of the analyzed portion of the TV measuring signal in the frame. At the end of this pulse, the second multiplexer 11 enters a state where the address code and other signals necessary for controlling the 1215 control blocks from the output of the computing unit

16 through block 11 are fed to the inputs of memory blocks 12-15. In this case, the computing unit 16 receives a sample of the TV measuring signal at the address specified by it.

When calculating by expression 2, for every four samples from memory blocks 12–15 corresponding to each value of the address, i.e. time t, the amplitude value of the low-frequency component of the TV measurement signal is obtained, which is recorded in the operational memory of the computing unit 16. The magnitude of the distortion — the effect of the chrominance signal on the luminance signal is determined in accordance with FIG. 6. If necessary, both averaging of data recorded from the seventh to eighth blocks 12-15 of memory can be used, as well as digital processing of the results of calculating the low-frequency component of the amplitude of the TV measuring signal (filtering, analyzing signal sections, etc.) and averaging the results calculating the effect parameter of the chroma signal on the luminance signal.

Depending on the type of TV path, the construction of sync blocks 7 and 9 varies:

1. In the case when the TV path is similar, low-frequency (0 ... 6 MHz), the output synchronization unit 7 (FIG. 2) contains a clock generator 21, generating two sequences of clock pulses, the repetition frequency of which satisfies the condition of the theorem Kotelnikov and corresponds to the sampling frequency of the TV-measuring signals.

The pulses are counted by a counter 18, which generates an address code. Shaper 19 pulses converts code

the addresses to the signals necessary to control the DAC 20, to which both clock sequences are received from the clock generator 21. DAC 20 converts

a sequence of samples in the form of codes in a sample of an analog TV signal.

The first spectrum conversion unit 22 performs the function of a low-pass filter that passes frequencies up to 6 MHz, and

If necessary, amplification of the power at its output forms an analogue TV signal. The input unit 9 of synchronization and interface with the TV path (Fig. 3), in this case contains the second conversion unit 23

spectrum filtering low frequencies in the band from 0 to 6 MHz, the output of which is fed to a parallel ADC 24. The zone generator 10 extracts from the TV signal horizontal and frame sync pulses and generates a parallel binary code of the current zone corresponding to the sample number in the line line number in the frame and the phase number of the signal using the system phase-locked loop

frequencies. Here, two clock pulse sequences are also generated, whose frequency is equal to the sampling frequency of the TV measuring signal, and the phase coincides, respectively, with the beginning and middle time of the current sample code. These clock pulses control the operation of the A / D converter 24, which converts the analog signal to a digital code, which is the output signal of block 9.

2. In the event that the TV path is analog, high frequency, the first spectrum conversion unit 22 provides the necessary spectrum conversions (modulation, filtering, etc.) in accordance with the selected TV system, as well as power amplification, and the second spectrum conversion unit 23 is the inverse transformation,

3. In the case of a digital TV path, blocks 7 and 9 perform the functions:

read synchronization from memory blocks 3-6 and writing data codes into memory blocks 12-15;

digital coding at the transmitting side and decoding at the receiving side:

power and signal level coupling.

4. In the case of a hybrid (analog-digital TV path), depending on the input,

TV path output, or both together - digital, use variants of blocks 7 and 9.

Implementing basic blocks and their nodes: the functions of block 1 calculating the components of TV measuring signals can be performed by a computer, such as a personal computer.

The pulse shaper 19 can be made on the basis of standard digital integrated circuits that provide the necessary decoding and pulse generation using triggers.

The proposed method, by forming a new type of TV measurement signals, provides for determining the amplitude law of the low frequency component for each sample of the TV measurement signal without applying a spectrum limit. This eliminates the errors introduced by this transformation.

In addition, the ability to analyze the entire shape of the curve makes it possible to clarify the optimal position of the characteristic points and, as a result, improve the measurement accuracy.

Claims (2)

1. A method for measuring the influence of a chroma signal on a television channel luminance signal, in accordance with which a low frequency (A) (t) and radio pulse (B (t) sin (1) i) components of the measurement signal are generated, where B (t) is a radio pulse envelope. the t-time component, the angular frequency, form the measurement signal in the form Uo (t) A (t) + B (t) sinftrt, pass it through the monitored television path, measure the instantaneous values of the signal A (t) at characteristic points, which determine the desired parameter, characterized in that, in order to improve the measurement accuracy, the measurement signal is additionally formed as U2 (t) A (t) + B (t) si n (an + l), it is passed through the television path, the instantaneous values of each of the two measuring signals U0 (t) and U2 (t) are measured at the output of the path and the instantaneous values of the low-frequency signal are determined at each time instant t using the formula A (t) (W + U2 (t) 2. The method according to claim 1, characterized in that the measuring signals are additionally formed as Uk (t) A (t) + B (t) sin (w t + k / 2), (k 1,3), pass them through the TV track, the instantaneous values of each of the four measurement signals are measured at the output of the path and the The instantaneous values of the low-frequency signal at each instant of time t are given by the formula A (t) 1 (t) + Ui (t) t U2 (t) + U3 (t). 1 e-vgtt OSHUOYSH QJJ3 IPNESS / iOE OL QP. fugitive  6.02 tJO 930 500 815.0 Figure 5 50 Compiled by A.Lapshov Editor N.Silgina Tehred M.MorgentalKorrektor N.Revska Order 1677 Circulation: Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. well. about NA, 1250 1128.5 1500 5 9-10.4 1253.0 NA