SU1358111A2 - Differential pulsed coder of television signal - Google Patents

Abstract

Invention m, b. used to reduce the amount of information transmitted without degrading the quality of signal transmission. The aim of the invention is to improve noise immunity. The device contains ADC 1, memory block 2, multiplier block 3, adders 4 and 6, inverter 5, module adder 7, quantizer 8 and encoding unit 9 consisting of decoder 10 and switches 11 and 12. 5 ill. SL 00 01 00

Description

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The invention relates to a technique of television, can be used to reduce the amount of transmitted information without degrading the quality of the transmission of a television signal and improves the device according to the basic author. St. No. 1056455.

The purpose of the invention is improving noise immunity.

FIG. 1 is an electrical block diagram of the differential pulse encoder of the television signal in FIG. 2 is a block diagram of the quantizer J in FIG. 3 is a transcoding table; in fig. 4 shows an algorithm for recovering signals at the receiving side; in fig. 5 shows examples of transmitting and recovering signals at the receiving side;

The differential pulse coder of a television signal (Fig. 1) contains an analog-digital converter (ADC) 1, memory block 2, multiplication unit 3, first adder 4, inverter 5, second adder 6, adder 7 modules, quantizer 8 and block 9 encoding consisting of the decoder 10 and the first 11 and second 12 switches.

The quantizer (Fig. 2) contains the first 13 and second 14 delay elements and the converter 15 codes.

Differential pulse encoder television signal works as follows.

In ADC 1, the analog television signal is digitized. In block 2 of the memory, due to the delay of the digital signal, a series of digital streams X; is formed, each of which corresponds to one of the elements of the multi-element aperture-group of eight adjacent picture elements. After multiplying each stream by a weighting factor 1/8 in block 3, multiplying in the first adder 4 calculates the average value of the signal level in the coded group a

 x In the adder 7 modules are

5 bi

the calculation of the half-sum of the modules of the deviation of 2 signal levels from

average value

Q

before

50

0

five

0

five

five

12

as well as the code of the signs of the difference S f S, -, i 1,8, where S 1, if X (-, a, and S; O - otherwise.

Claims (1)

Codes a,., A, and S are fed to quantizer 8, where quantization is carried out in code converter 15 according to the table in FIG. 3 and the delay for the time of this quantization of the codes a and S come to encoding unit 9. Code and is fed to the input of the decoder 10, the signal at the output of which takes the level of logic 1 at a O and the level of logic O otherwise. The signal from the output of the decoder is control for the first 11 and second 12 switches. If the signal from the output of the decoder 10 is equal to one, then in the first switch all bits a 2 are equal to the second bit a, Otherwise, i.e. when aO, the true value of a is transmitted to the output of the first switch 11. At the same time, with the signal at the output of the decoder corresponding to the logic level 1, in the second switch 12 all eight bits S are equalized to the most significant bit and are transmitted to its output. Otherwise, the true value S is transmitted to the output of the second switch 12. Formula of the invention Differential pulse encoder television signal auth. St. No. 1056455, characterized in that, in order to increase the noise immunity, the coding unit is designed as a decoder, first and second switches, the decoder input, the first signal inputs of the first and second switches are the inputs of the coding unit, the outputs of the first and second switches are the first and second outputs of the coding unit, the third output of which is combined with the first signal input of the first switch and the second signal input of the second switch, the control input of which is combined with a control input the house of the first switch and connected to the output of the decoder, the input of which is combined with the second signal input of the first switch. Jlfl / j .jiZEl ZlL j , 2 /four 15 2 Fig.Z a1.ag, 5 Not phage 5