KR890004316B1 - Convertor to run-length codes - Google Patents

Abstract

The method comprises a first step for checking an end block if the end value is zero, a second step for checking whether former counted value of a zero-run counter is zero if the end block is not zero, a third step for reading new data from a RAm (30) if the output of the zero-run counter is zero, a forth step for converting the output of the zero-run counter if the output of the zero-run counter is not zero, a fifth step for finding the code corresponding to the zero in the legnth code unit if the zero is existing and for converting the value corresponding to the data, and a sixth step for converting the code corresponding to the zero counter for endowing the run-length pre-fix to store in RAM (30) for data transmission if the output of the zero-run counter is larger than 1.

Description

Complex code encoding method

1 is a system diagram according to the present invention.

2 is a flow chart in accordance with the present invention.

3 is a diagram illustrating a complex code memory according to the present invention.

* Explanation of symbols for main parts of the drawings

10: central processing unit 20: ROM

30: RAM 40: Transmission Device

The present invention relates to a complex code coding method for data transmission. In particular, in the case of image data transmission, a variable length value code part and a continuous length code part are provided so that when there is one zero value among transmission compression codes, The present invention relates to a complex code coding method capable of increasing a transmission compression ratio and shortening a transmission time by providing a program to be processed in a variable length code value code section instead of a length code section.

In general, image transmission is a recent trend to shorten the transmission time by reducing the transmission amount in a range that does not impair the quality of the image. As a conventional method for this, a method combining a discrete cosine transform (DCT) and a run length coding (RLC) has been used.

The conventional method will be described in detail by dividing image data into blocks such as 16 × 16 or 8 × 8, and performing DCT for each block using a zigzag scan to determine DCT coefficients of 16 × 16 or 8 × 8. RLC was performed.

When performing the RLC, inefficient RLC is performed in many blocks without considering DCT coefficient distribution in the block, thereby increasing the total transmission amount.

Therefore, in order to solve this problem, the applicant of the present application has applied for a method of reducing the total transmission amount by changing the method of RLC according to the distribution structure of DCT coefficients for each block (Patent Application Nos. 86-9696 and 86-9697). number)

When DCT of the transmission data, zero and non-zero values are distributed. Subsequently, it is common practice to create a code table for each of the two cases in RLC. However, if there is only one value of zero, there is a reference code (Run Length Prefix). There is a problem in that the transmission efficiency is reduced since the transmission is added.

Accordingly, an object of the present invention is to provide a complex code encoding method in which a variable value code unit does not process a zero continuous length code unit when only one zero is continuous from a zero value of a DCT value.

Another object of the present invention is to provide a method for shortening the image data transmission time.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram according to the present invention, which converts a code of transmission data by a program according to an input, and fixes a system control program, a zero continuous length code and a variable length code. ROM 20 embedded as data, RAM 30 which randomly stores transmission data DCT as image data, and modulates the digital signal to be suitable for analog transmission, receive the modulated signal, and then demodulate it. The transmission device 40 converts the original data.

2 is a flowchart according to the present invention, and FIG. 3 is an example of a complex code according to the present invention, where 3A is a variable length value code and 3B is a zero continuous length code.

In (3A) and (3B), a special code includes an end-of-segment code (EOB), a reference code, a value up code, and a zero up code.

Therefore, a specific embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3 as described above. When DCT data to be transmitted enters the RAM 30 under the control of the CPU 10, the RLC is transmitted in the transmission mode. In the process (2a), the CPU 10 checks the end of the block of one frame and reads data for transmission (hereinafter referred to as "x") in the process (2c).

When " x " is zero, the next data is read while increasing the zero run counter (hereinafter referred to as ZRC) by one.

Continue reading in the above process, and if it is not zero, it is checked in step (2f) whether the previous ZRC is zero or not.

If it is not zero in step (2f), the conversion for zero run is performed. In step (2g), it is checked whether zero is "one". In the case of one in the step (2g), the code address is specified in the range of PBASE (0-15) in the step (2h), then the ZRC is cleared for the next, and the value specified in the step (2i) is read from the ROM 20. . That is, "1" of the variable length code part 3A is input to the RAM 30 which is the code memory in the process (2j), and then the conversion of "x" is performed.

In the case of (2g), if there is more than one zero, in step (2k), it checks 15 zeros, and if it is more than 15, add ZRC to "ZBASE" which can designate the number of zeros. After designating the address of the embedded ROM 20 and clearing the ZRC for the next function, and storing the reference code ("101") in the RAM 30 before the code read in the ROM 20, the following is zero consecutive. It can be found in the length code 3B.

For example, when the code conversion is described as "1" which is -4 of the 3rd degree variable length code part 3A, since zero is five consecutively, since "1" is found in 3rd degree 3B, If it is reduced and converted, and the reference code "101" is given again, in (3B), "10" is found because zero is three consecutive times again.

If ZRC is not "0" in the process (2f), after the conversion code is stored in the RAM 30, and if the ZRC is "0", it is checked whether the x value is positive or negative in the process (2n) x <0 Is greater than or less than -16, and if x is not greater than -16, replace the x value with an absolute value and add a negative value to specify the address of the ROM 20 in step (2v). The code is read in step 2w) and stored in the RAM 30 in step 2t.

When the value of x is greater than 0 in step (2n), when x> 16 in step (2o) of FIG. 2, the address of the ROM 20 is added to the value of the ROM 20 by adding PBASE (0-15) to the value of x. After reading the code in the process (2g) by specifying in the RAM (30) stored in the process (2t). In the process (2o) or (2u), if x is greater than 16 or x is less than -16, the upcode (0001) of FIG. 3A (3A) is assigned to (2r) and the process (2r) is performed. Another "x" value (X 8Bit) of 8 bits is assigned to the upcode of (2s), and the code is stored in the code memory of the RAM 30 (2t).

On the other hand, when ZRC is greater than 15 in step (2k), a zero up code (0000001) is assigned in step (2x) in (3B) of FIG. 3, and a 6-bit code is added to the code given in step (2x). Save to 30.

Also, at the end of the block in step (2a), the section end code (00001) of FIG. 3 (3A) is imposed in step (2z), and if it is zero, 00001 is given to indicate the end of the bit (EOB).

The code value of the RAM 30 processed in the above process is transmitted to the aerial signal through the modem 40 or other output device.

As described above, there is an advantage that the transmission time can be shortened by employing a new complex code when transmitting image data.

Claims (1)

A RAM 30 capable of randomly storing image data of a subject, a ROM 20 having a system control program and fixed code data, and receiving data to be transmitted from the RAM 30 according to a program of the ROM 20 In the code encoding method in a system having a central processing unit (10) and a transmission unit (40) capable of transmitting and receiving data processed by the central processing unit (10), one block from the RAM (30) A first step of checking whether the end of the first processing unit is zero after checking the end of the second processing unit; and a second step of checking whether or not the zero continuous counter value before the first step is zero if the first step is not zero; If the zero continuous counter value of the second process is zero, data of zero is not inputted before. Therefore, the code is converted from the conversion length code of the ROM 20 and the new data is read from the RAM 30. Is a third process, a fourth process for converting to a zero continuation if the zero continuous counter is not zero in the second process, and if the value is 1 in the fourth process, one zero value is previously inputted. A fifth process of converting a value for data after finding a code for zero in the conversion length code part of (20) and inputting it to the RAM 30; and a zero successive counter value greater than 1 in the second process. And a sixth step of converting the code according to the zero continuation counter in the zero sequential conversion code section of (20) to give a reference code to the code and storing it in the RAM 30 to be transmitted in the transmission mode. Coding method.

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