SU1518922A1 - Image signal coder - Google Patents

Abstract

The invention relates to computing. The purpose of the invention is to improve the quality of encoded images by increasing the clarity of the borders of large parts. The encoder contains a register 1, a television transmitting chamber 2, an ADC 3, an adder 4, delay blocks 5 and 11, a comparators block 6, a code converter 7, a subtractor 8, a code comparator 9 and a group code generation unit 10. In the encoder, for groups corresponding to large parts, a code of digits of the deviations is transmitted. On the receiving side, such groups are restored using two levels. As a result, the blurring of the borders of large parts is reduced and the image quality is enhanced. 2 Il.

Description

one

(21) 4363141 / 24-09

(22) 01/13/88

(46) 10/30/89. Bul № 40 (72) S.A. Kulikov

(53) 621,397 (038.8)

(56) Copyright certificate (; С (; Р № 1035832, cl. Н 04 N 5/14, 1982.

USSR Author's Certificate No. 684779, cl. H 04 N 5/14, 197V.

(54) IMAGE ALARM CODE

(57) The invention relates to computing. The purpose of the invention is to improve the quality of KOAHpopaiiHbix images by increasing the clarity

the boundaries of large parts. The encoder contains a register 1, a television transmitting chamber 2, an ADC 3, an adder 4, delay blocks 5 and 11, a comparators block 6, a code converter 7, a subtractor 8, a code comparator 9 and a group code generation unit 10. In the encoder / dl groups, corresponding to large large parts, the code of the digits symbols is transmitted. On the receiving side, such groups are restored using two levels. As a result, the blurring of the boundaries of large parts is reduced and the quality of the image increases. 2 ill., 1 tab.

The invention relates to computing technology and communication technology and can be used when building digital television systems to efficiently encode TV images.

The purpose of the invention is to improve the quality of encoded images by increasing the clarity of the borders of large parts.

FIG. Figure 1 shows the electrical structure of the image signal coder; in fig. 2 - functional block diagram of the formation of the group code.

The image signal encoder (Fig. 1) contains a register 1, a TV transmitting camera 2, an analog-to-digital converter (ADC) 3, an adder 4, a first delay block 5, a comparators block 6, a code converter 7, a subtractor 8, a comparator 9 codes, a block 10 forming the group code and the second block 1 1 delay.

The group code generation unit 10 contains (FIG. 2) a di-diffuser 12, a switching unit 13 and an output parallel-sequential register 14.

The device works as follows.

The analog signal from the output of the TV transmitting chamber 2 is fed to the input of the ADC 3, where the time discretization and quantization of the level by an eight-bit code occur. The digital output signal is fed to the first input of the adder 4 and the input of the second block 11 of the delay. In adder 4, the next element is added to the sum of the previous ones, arriving at the second input of adder 4 from the output of the first b block b delay. After the arrival of every fourth element at the second input of the adder 4, the sum of the three previous elements is found, and at the beginning of the day, the sum of the four adders 4 is the sum of four elements of the coded group. This sum of the frequency of frequency A is recorded in

"

i

(L

ate

iiap. ijijiijjit.iibui register 1, from which (: chity.1yutts c c i-arshi raprr S-times the sum code, that is, the average brightness of the encoded 1 rump. On the same tlkgu there is a record from the second register 11 delay n its parallel pei HCTP.

Tlkim way, at the output of the second block 11 and register 1 during the cycle fr / are X, X, X, X, X and X, respectively.

Rce four elements X, - (, 4) are fed to the first inputs of the iTopon 6-unit block, to the second inputs of which, under leTCH, the XCT code from the register 1 output.

In block 6, a four-region dt code T c, is formed, where r .; sign (X; - XCD), which is fed to the input of converter 7, from which a three-digit code T, is read. The first input of the subtractor 8 receives the code X, the second Xj.p. In the subtractor 8, the difference modulus code (Xd-X (.p) is generated, which is transmitted to the input of the code comparator 9, where it is compared to the nopoj OBbiM code value. The comparison result is the transition bit (PD)) transmitted to the group 10 codes X, Xp, T f are also received.

The eight-bit output code word of the coded group is generated as follows.

One bit of it is the bit transition BP, equal to one, if the condition

T,; UUU, 001, U10,011,1UU, 101 and

BP 140

The PD bit is generated at the output of the decoder 12 and is the control for the switch 13. If, then the output of block 13 is connected to the eight-bit code word consisting of the bit discharge and the mixture of bits Chrr. . In the case of BP-1, the eight-bit word at the output of the switch consists

from BP, A bit X and 3 bits

t with;

The formed group word in the parallel code enters a parallel-serial register and then into the channel.

4x converter

code T to a three bit digit code T. is produced in accordance with the recoding table.

The first six code combinations of code T correspond to large details of the image, the rest to small and diverse (combination 1111) sections. As follows from the table, the code combination corresponding to the fine details corresponds to the same code combination 110.

In the device for groups corresponding to large parts, a code of digits of the deviations is transmitted. On the receiving side, such groups are restored using 2 levels. As a result, the blurring of the borders of large parts is reduced and the quality of the decoded images is improved compared with the known device.

Claims (1)

Invention Formula An image signal encoder containing a register, serially connected television transmitting camera, an analog-to-digital converter (ADC), an adder and a first delay unit, the output of which is connected to a second adder input, characterized in that, in order to improve the quality of the coded images, to increase the clarity of the boundaries of large parts; a comparators block, a code converter, a quiver, a code comparator, a shaper code generation unit 1, and a second delay unit, whose input is connected to the ADC output, and d second unit delay coupled to the first inputs of the subtractor, the code forming unit the group and comparators block, whose Bbixcvi is connected via the code converter to the second input of the group code generation unit whose output is the communication line input, and the third input of the group code generation unit is connected to the code comparator output whose first input is the input not (.3.5.11 L on; transmitting cunxpofffffpamap the threshold value is codel, and the second input is connected to the output of the subtractor, the second input of which is connected to the second input of the comparators block, the fourth input of the group code forming unit and the output of the register whose input poi o is connected to the output of the adder. ten jg j0 napoeoloe value FIG. one