JP3868148B2 - Code data output device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sign-data output device, in particular, ITU-T.82 zero to more trailing consecutive encoded one stripe of data into JBIG (Joint Bi-level Image Coding Experts Group) method based on Korea It relates also One sign-data output device the ability to remove (OxOO).
[0002]
[Prior art]
The JBIG system is an international standard for predictive coding of binary images, and a system based on the ITU-T.82 recommendation or the ITU-T.85 recommendation is known.
[0003]
In the JBIG system recommended by ITU-T.82 and T.85, it is standardized that 128 lines of image data are defined as one stripe for transmission image encoding, and transmission is performed in units of stripes. It is specified that an SDNORM or SDRST marker code is added to the end of.
[0004]
In addition, it is specified that consecutive zero (hexadecimal 0x00) bytes existing at the end of one stripe code string may be deleted without being transmitted. When the 0x00 byte is deleted on the transmitting side, an operation of intentionally inserting the 0x00 byte is performed on the receiving side, and then decrypted.
[0005]
[Problems to be solved by the invention]
As described above, according to the ITU-T.82 recommendation, the last 0x00 byte at the end of the stripe may be deleted. That is, 0x00 at the end of the stripe is not essential, so it is extra code data, and it is naturally desirable to delete it in order to improve the compression rate.
[0006]
As a method of deleting consecutive zeros (0x00) at the end of the stripe, there is a method of searching for a pattern that continues with 0x00 by software and deleting it.
[0007]
However, this method requires a step of searching for a pattern in which trailing zeros are continuous for each stripe, resulting in an increase in software load.
[0008]
The present invention has been made to eliminate such inconveniences, and aims to efficiently delete consecutive zeros existing at the end of one stripe without increasing the software load. .
[0009]
[Means for Solving the Problems]
In the present invention, the content of code data output from the encoding device is determined, and at least consecutive zeros (0x00) are not passed to the next processing as they are, but instead, how many consecutive zeros continue. Is obtained, the information is temporarily stored, and then the information is output at a timing satisfying a predetermined condition.
[0010]
That is, continuous zero information is always managed centrally. Each time one stripe end is completed, the continuous zero information stored at that time is stopped, so that the continuous zero at one stripe end can be deleted mechanically (automatically). it can.
[0011]
In other words, by adopting a system configuration that is easy to realize that centrally manages information on consecutive zeros, it is possible to efficiently delete consecutive zeros at the stripe ends. Also, no special burden is placed on the software.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the first aspect of the present invention, determination means for sequentially determining whether or not the bytes of code data encoded and input by JBIG (Joint Bi-level Image Coding Experts Group) are continuous zero ( 0x00 ) A count value holding unit that holds a count value that counts consecutive zeros in the code data, a storage unit that stores data to be output, and a zero in which the latest byte of the code data is continuous by the determination unit. When it is determined that there is an increment unit that increments the count value held by the count value holding unit, and when the determination unit determines that the latest byte of the code data is not continuous zero, the count value Add consecutive zeros and the most recent byte repeated to the storage means for the number of count values held in the holding means. Both include reset means for resetting the count value, and output means for resetting the count value and outputting the data stored in the storage means when a stripe end of the code data is detected. It is characterized by.
[0013]
In this way, when the stripe end of the code data is detected, the count value for counting consecutive zeros is reset, so that the consecutive zeros at the end of the stripe can be deleted without imposing a burden on software.
[0014]
In the second aspect of the present invention, it is sequentially determined whether the bytes of the encoded data encoded and input by the JBIG method are continuous zero ( 0x00 ), continuous F ( 0xFF ), or other than that. Determination means, count value holding means for holding a zero count value for counting consecutive zeros in the code data, and an F count value for counting consecutive Fs in the code data, and storing output data A storage unit; and a zero increment unit that increments a zero count value held by the count value holding unit when the determination unit determines that the latest byte of the code data is continuous zero; and the determination unit When the latest byte of the code data is determined to be consecutive F by the count value holding means, F increment means for incrementing the F count value, and when the determination means determines that the latest byte of the code data is neither continuous zero nor continuous F, the zero held in the count value holding means A continuous zero that repeats the count number of times or a continuous F that repeats the count of the count value and the latest byte, and a reset means that resets the zero count value or the F count value; An output means for resetting the zero count value and outputting the data stored in the storage means when a stripe end of data is detected, and the count value holding means receives a carry signal; When the F count value is 1 or more, the F count value is copied to the zero count value, and the F count value is Characterized by resetting the cement value.
[0015]
In this way, when consecutive Fs are counted and a carry signal is received, if the F count value is 1 or more, the F count value is copied to the zero count value and the carry is reset by resetting the F count value. Even if it occurs, it can respond accurately.
[0022]
According to a third aspect of the present invention, there is provided a communication apparatus including the code data output apparatus according to the first or second aspect.
[0023]
In the communication apparatus according to this aspect, it is possible to efficiently delete unnecessary consecutive zeros without imposing a burden on software, and it is possible to increase the compression rate of transmission image data.
[0024]
Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings.
[0025]
FIG. 1 is a block diagram showing a main configuration of a communication apparatus (for example, a facsimile apparatus) equipped with the code output apparatus of the present invention.
[0026]
As shown in the figure, the communication apparatus includes a Markov model encoding apparatus 10, a code data output apparatus 20 according to the present invention, a modem 32, and a control unit 40. Reference numeral 50 is a communication apparatus of the other party.
[0027]
The Markov model encoder 10 includes an image data input unit 11, a context data generator 12, a context data RAM 13, an arithmetic encoder (QM coder) 14, and a probability estimation table 15.
[0028]
The arithmetic encoder 14 follows the fluctuation of the local statistics of the image, estimates the LPS (inferior symbol) generation probability, and generates a code as a penalty that cannot be correctly estimated. Reflects local features of the image. Since the arithmetic encoder (QM coder) is known, the details of its operation are omitted.
[0029]
The code output device 20 according to the present invention includes a code data determination unit 21, a register 22, a “0x00” counter 23, a “0xFF” counter 24, a marker code generation unit 25, a selector 28, and code data. An output unit 29 and a memory 30 are provided.
[0030]
The feature of the code output device 20 of the present embodiment is that the information of continuous zeros (0x00) is always managed centrally by the “0x00” counter 23, and when the control unit 40 detects the stripe end, That is, the count value of the “0x00” counter 23 is discarded, thereby making it possible to efficiently delete consecutive zeros at the stripe end.
[0031]
Hereinafter, functions of each unit and characteristic operations will be described.
[0032]
The code data determination unit 21 analyzes the contents of the codes output from the arithmetic encoder 14 and classifies them into “continuous zero (0x00)”, “continuous F (0xFF)”, and “other codes”.
[0033]
In the case of 0x00, the “0x00” counter 23 is notified (the 0x00 itself is not output), and the “0x00” counter 23 counts the number of notifications (the number of bytes of the code).
[0034]
Similarly, in the case of 0xFF, the code data determination unit 21 notifies the “0xFF” counter 24 (0xFF itself is not output), and the “0xFF” counter 24 that has received this notification counts the number of times (code byte). Count).
[0035]
In addition, in the case of other codes, the code determination unit 21 outputs the code as it is and temporarily stores it in the register 22. Note that the register 22 is a FIFO-type memory, and every time data is newly written, the data held so far is output.
[0036]
In addition, the code determination unit 21 sends a reset signal to the “0x00” counter 23 when a non-zero code comes in a state where zeros continue. Similarly, the code determination unit 21 sends a reset signal to the “0xFF” counter 24 when a code other than F is received in a state where F continues.
[0037]
The carry (carry signal) output from the arithmetic encoder 14 is transmitted to the “0xFF” counter 24 and the register 22 via the signal line L1.
[0038]
When a carry is input while the “0xFF” counter 24 is counting 1 or more, the count value of the “0xFF” counter 24 is copied to the “0x00” counter 23. This is because, by bit inversion, a new zero is generated by the count value of the “0xFF” counter 24, so it is necessary to notify this to the “0x00” counter 23 that manages the zero information. Because. By such an operation, even when a carry occurs (when a carry occurs), it is possible to accurately cope with it. When the above copy is executed, the “0xFF” counter 24 is reset.
[0039]
Further, when a carry is input, the register 22 adds 1 to the code data held at that time (increment the held data).
[0040]
Each of the “0x00” counter 23 and the “0xFF” counter 24 outputs the count value held when the reset signal is received from the code data determination unit 21. In response to the output count value, the “0x00” output unit 26 and the “0xFF” output unit 27 output 0x00 and 0xFF corresponding to the count value, respectively.
[0041]
The marker code generator 25 generates and outputs an SDNORM or SDRST marker code to be added to the end of one stripe.
[0042]
The code data output from the register 22, the code data “0x00” and “0xFF” output from the “0x00” output unit 26 or the “0xFF” output unit 27, and the marker code generation unit 25 output the code data. The marker code is sequentially sent to the code data output unit 29 via the selector 28, where it is assembled into code data for one stripe to be transmitted, and is temporarily held in the memory 30.
[0043]
In the code output device 20, the above operation is always performed. When the control unit 40 detects the stripe end (that is, detects the output of the code for 128 lines), the count value held in the “0x00” counter 23 at that time is discarded. As a result, consecutive zeros at the end of the stripe are not output, transmission of extra codes is prevented, and the compression rate is improved accordingly.
[0044]
On the other hand, when the control unit 40 detects the stripe end and the “0xFF” counter 24 holds a count value of 1 or more, it is output as it is. This is because the continuous F at the end of the stripe is useful information that must be transmitted, unlike the case of zero.
[0045]
In FIG. 1, the “0x00” counter 23 and the “0xFF” counter 24 are depicted as separate counters. However, since these counters do not simultaneously perform a counting operation, one counter is divided in a time-sharing manner. It is also possible to use it.
[0046]
The characteristic operations described above are summarized as shown in FIG.
[0047]
That is, first, the code data determination unit 21 determines “continuous 0”, “continuous F”, and “other codes” (step 60).
[0048]
As a result of the determination, in the case of “other code”, the value is accumulated in the register 22, and in the case of “continuous 0”, the “0x00” counter 23 counts the number thereof, and the code data determination unit When there is a reset instruction from 21, the number of bytes of the code is output. In the case of “continuous F”, the “0xFF” counter 24 counts the number, and when the code data determination unit 21 receives a reset instruction. When the carry is output when the “0xFF” counter 24 counts “1” or more, the count value is copied to the “0x00” counter 23, , “0x00” counter 23 is reset (step 61).
[0049]
When the control unit 40 detects that the stripe end has been reached, the count value held by the “0x00” counter 23 is discarded (ignored) at that time, while the count value of the “0xFF” counter 24 is Output as is.
[0050]
FIG. 3 is a block diagram showing a hardware configuration of a facsimile machine equipped with the code output device described above.
[0051]
As shown in the figure, the facsimile apparatus 101 includes a host processor 102, an MH / MR / MMR encoding / decoding circuit 103, a resolution conversion circuit 104, a QM (arithmetic) encoding / decoding circuit 105, and an image line memory. 106, a code memory 107, a communication interface such as a modem (functioning as an interface for wired transmission using the telephone line 113) 108, an image input device 111 such as a scanner, and an image recording / display such as a printer And each block can exchange information with each other via the internal buses 109 and 110.
[0052]
The Markov model encoding apparatus 10 and the code output apparatus 20 described with reference to FIG. 1 are mounted on a QM (arithmetic) encoding / decoding circuit 105.
[0053]
Since the code output apparatus of the present invention has a simple configuration, it can be sufficiently installed in a facsimile apparatus that is required to be downsized and cost-reduced, thereby reducing the compression rate without imposing a burden on software. Can be improved. Therefore, it contributes to the improvement of the communication performance of the popular facsimile machine.
[0054]
【The invention's effect】
As described above, according to the present invention, the configuration in which continuous zeros included in the code data are managed in an integrated manner is adopted, and the continuous zeros existing at the end of one stripe without increasing the software load. Can be deleted efficiently, and the compression rate of the image data can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main configuration of a communication apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart for explaining main operations of the code output apparatus according to the embodiment. Block diagram showing the hardware configuration of a facsimile machine equipped with the code output device of the invention.
DESCRIPTION OF SYMBOLS 10 Markov model encoding apparatus 11 Image data input part 12 Context data generation part 13 Context data RAM
14 Arithmetic encoder 15 Probability estimation table 20 Code output device 21 Code data determination unit 22 Register 23 “0x00” counter 24 “0xFF” counter 25 Marker code generation unit 26 “0x00” output unit 27 “0xFF” output unit 28 Selector 29 Code Data output unit 30 Memory 32 Modem 40 Control unit 50 Communication device

Claims (3)

Judgment means for sequentially judging whether or not the bytes of code data encoded and inputted by the JBIG (Joint Bi-level Image Coding Experts Group) method are consecutive zeros ( 0x00 );
Count value holding means for holding a count value for counting consecutive zeros in the code data;
Storage means for storing data to be output;
An increment means for incrementing the count value held by the count value holding means when the determination means determines that the latest byte of the code data is consecutive zeros;
When it is determined by the determination means that the latest byte of the code data is not a continuous zero, consecutive zeros and the latest byte repeated for the count value held in the count value holding means are stored in the storage means. And a reset means for resetting the count value,
When the stripe end of the code data is detected, the count value is reset, and output means for outputting the data accumulated in the accumulation means;
Encoded data output apparatus characterized by comprising a. Determining means for sequentially determining whether the bytes of the encoded data encoded and input by the JBIG method are continuous zero ( 0x00 ), continuous F ( 0xFF ), or other;
Count value holding means for holding a zero count value for counting consecutive zeros in the code data and an F count value for counting consecutive Fs in the code data;
Storage means for storing data to be output;
A zero increment means for incrementing a zero count value held by the count value holding means when the determination means determines that the latest byte of the code data is a consecutive zero;
An F increment means for incrementing the F count value held by the count value holding means when the determination means determines that the latest byte of the code data is a continuous F;
If it is determined by the determination means that the latest byte of the code data is neither continuous zero nor continuous F, the number of consecutive zeros or F count values repeated for the number of zero count values held in the count value holding means Adding a continuous F repeated the number of times and the latest byte to the storage means, and resetting the zero count value or the F count value;
When the stripe end of the code data is detected, the zero count value is reset, and output means for outputting the data accumulated in the accumulation means,
With
When the carry value signal is received, the count value holding unit copies the F count value to the zero count value and resets the F count value when the F count value is 1 or more. Data output device . A communication device comprising the code data output device according to claim 1.

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