JPS6220474A - Encoding system for picture information - Google Patents

Abstract

PURPOSE:To improve an encoding rate greatly by encoding run-length encoded data of one line further shortly when the same data succeeds in the run-length encoded data. CONSTITUTION:A picture signal outputted by a scanner 1 is encoded on run- length basis by an encoding and decoding part 6. The obtained code data is compart at intervals of one main scanning line and when main scanning lines having the same contents succeed, the code data of the scanning lines are stored in a succeeding line memory 7 and storage address information on the code data of the main scanning line in the succeeding line memory 7 and the number of the succeeding data are stored in a page memory 8 instead of run-length codes. Further, a section code CDD is inserted right after the run-length code of a main scanning line right before the succeeding main scanning line so as to identify normal run-length codes from its storage address information and the number of succeeding codes.

Description

[Detailed description of the invention] [Technical field] The present invention relates to an encoding method for image information.

[Prior Art] In general, image information has a very large amount of information and a high degree of redundancy, so image information processing devices that store and transmit image information compress the redundancy of the information. The amount of image information is compressed by applying this encoding method.

For example, for facsimile machines that transmit image information, standard one-dimensional and two-dimensional encoding systems have been established in accordance with the recommendations of the ccIrT (International Telegraph and Telephone Consultative Committee). The amount of information per standard original document is compressed to less than 175, and the transmission time for one standard original document is reduced to less than 1 minute.

However, conventional image information encoding methods basically end when the image information output from the image reading device is encoded, and the encoded data obtained through the encoding process is stored or transmitted. Therefore, encoding using the relationship between the main scanning lines is not performed, and as a result, there is a problem in that the encoding rate is relatively low.

[Purpose] The present invention has been made to solve the problems of the prior art described above, and it is an object of the present invention to provide an encoding method for image information with an improved encoding rate.

[Configuration] In order to achieve this object, the present invention compares run-length codes for each main scanning line, and when main scanning lines with the same content are consecutive, the run-length code of the immediately preceding main scanning line is compared. After placing a predetermined delimiter code immediately after, information representing the number of consecutive delimiters and the content of the run-length code in the main scanning line is output instead of the run-length code.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a facsimile machine according to an embodiment of the present invention.

In the figure, a scanner 1 reads an image of a transmitted document at a predetermined resolution, and an image signal outputted from the scanner 1 is outputted to a pass line 3 via a buffer 2. The plotter 4 records and outputs the received image, and its recording signal is applied to the plotter 4 from the pass line 3 via the buffer 5.

The encoding/decoding unit 6 performs run-length encoding on the image signal output from the scanner 1, and compares the encoded data obtained thereby for each main scanning line. , stores the code data of the main scanning line in the continuous line memory 7, and stores the code data of the main scanning line in the continuous line memory 7.
storage address information of the code data of the main scanning line in ,
The consecutive numbers are replaced with run-length codes in page memory 8.
to be memorized. In addition, 1. In order to identify the normal run-length code, its storage address information, and the consecutive number, a delimiter code COD is inserted immediately after the run-length code of the main scanning line immediately before the consecutive main scanning lines. .

As shown in FIG. 2, the continuous line memory 7 is a line memory LM having a storage capacity of the maximum line length.

A memory table is formed by consecutively arranging a plurality of pieces of memory address information ADD for identifying each line memory LH, and furthermore, a plurality of pieces of this memory table (for example, documents that can be stored in the page memory Number of sheets) It has an arranged configuration. Further, for example, if the storage address information ADD is 1 byte (=8 bits) data, 256 line memories LM are arranged in one memory table.

The page memory 8 is a memory having a capacity capable of storing run-length codes corresponding to standard originals for a large number of sheets.

The system control unit 9 consists of a microprocessor, a memory storing its control program, etc., and peripheral devices.
Each element of this facsimile machine is properly controlled to operate the facsimile machine as a whole, and the modem 1
0 modulates the transmission information using a predetermined modulation method, and
It demodulates the received signal to the original information. This modem 1o and a transmission line (for example, a public telephone line) are connected via a network control device 11.

It should be noted that each part of this facsimile apparatus except for the encoding/decoding system has the same structure as the conventional one, and therefore, detailed explanation thereof will be omitted.

With the above configuration, encoding processing by the encoding/decoding section 6 will be described first.

In this case, for example, when the operator sets a document to be transmitted on the scanner 1 and then inputs a command to start transmission from the operation section (path shown), the system control section 9 activates the scanner 1 and starts scanning the first document. The encoding/decoding unit 6 is instructed to encode the image information.

Thereby, the encoding/decoding unit 6 executes encoding processing as shown in FIG.

That is, first, a counter m for storing the number of consecutive main scanning lines (hereinafter referred to as lines) with the same content and a counter n for storing the number of processed lines are initialized to 1 and O, respectively (step 101). ), buffers BFI and BF2 that store the run-length codes of the encoded line and the immediately preceding line are cleared, respectively, in order to compare the contents of the lines (process 102).

Then, after moving the memory contents of buffer BF1 to buffer BF2 (process 103), the counter n is incremented to prepare for the next line (process 104), and one page is transferred based on the value of counter n. It is determined whether the encoding process has been completed (determination 105).

If the result of this judgment 105 is No, the image information of the n-th line is input via the buffer 2 and the pass line 3 (process 106), and the encoding process 107 is executed to run-length encode the data of that line. Later, the resulting run-length code for one line is stored in the buffer BF.
1 (process 107).

Then, compare buffer BFI and buffer BF2 (
Judgment 109). If both are equal and the result of this judgment 109 is YES, the lines with the same content are consecutive, so the counter m is incremented (process 110).
, the process returns to step 103.

Further, if the result of the determination 109 is NO, the value of the counter m is compared with 1 (determination 111). This judgment 111
If the result is YES, this means that lines with the same content are not consecutive, so the content of the buffer BF2 at that time is added to the beginning of the free area of the page memory 8 (process 112).

On the other hand, if the result of judgment 111 is NO, it means that the same content has just continued for m lines.
In the continuous line memory 7, it is stored in the first line memory LM of the free area of the memory table corresponding to the number of pages of the transmission document notified from the system control unit 9 at this time (processing 113).

The storage address information ADD corresponding to the stored line memory LM is extracted.

Then, the delimiter code CDD, the storage address information ADD, and the value of the counter m are added to the beginning of the free area of the page memory 8 (step 114), and the process returns to step 103.

The above process is repeatedly executed, and when it is determined in judgment 105 that the encoding process for one page has been completed, this process is terminated, and the system control also indicates that the encoding process for 1/2 minutes has been completed. Notify Department 9.

As a result, if a subsequent document is set in the scanner 1, the system control section 9 operates the scanner 1 and instructs the encoding/decoding section 6 to encode the second document. .

Therefore, the above-described encoding process is repeatedly executed, and at this time, the memory table in the continuous line memory 7 that corresponds to the second transmission document is selected.

The above operations are sequentially and repeatedly performed until all images of the transmission document set on the scanner 1 are read.

Note that the scanner 1 notifies the system control section 9 of the size information of the document, and the system control section 9 notifies the encoding/decoding section 6 of this size information in advance. As a result, the total number of lines corresponding to this size information is used as the criterion for determining the end of a page in the process 105 described above.

When the image information of all transmitted documents is encoded and stored in the continuous line memory 7 and page memory 8 in this way, the system control unit 9 sends a call to the destination instructed by the operator using the network control device 11. When the line is set up, a predetermined transmission control procedure is executed, and the contents stored in the continuous line memory 7 are transmitted to the destination terminal before transmitting the image information.
The stored contents are transmitted to the destination terminal.

The receiving terminal (that is, the destination terminal) has the same configuration as the sending terminal, that is, the facsimile machine shown in FIG. Sequential continuous line memory 7
The image information transmitted thereafter is temporarily stored in the page memory 8.

In this way, the reception of image information is completed.

The system control section 9 instructs the encoding/decoding section 6 to first decode the received information of the first image into the original image information. Thereby, the encoding/decoding unit 6 decodes the received information into the original image information by the process shown in FIG.

That is, first, a counter n for storing the number of processed lines is initialized to O (process 201).

Then, after incrementing the counter n (processing 2
02), based on the value, it is determined whether the processing of one page has been completed (determination 203).

If the result of this judgment is NO, from the page memory 8. Process 204) to input the data of the th line, and determine whether the first code is the delimiter code CDD (
Judgment 205).

Now, considering the storage state of data in the page memory 8, as shown in FIG. A plurality of length codes are stored.

In addition, for data in parts where the same content is continuous, a delimiter code COD is placed following the line end signal EOL,
Furthermore, 1-byte storage address information ADD and a 1-byte counter m, ie, the number of consecutive lines, are arranged consecutively.

Therefore, if the result of the judgment 205 is NO, the normal decoding process 206 is executed, the image information decoded by this is stored in the buffer 5 via the pass line 3, and then the process returns to the process 202. . The image information stored in the buffer 5 is read by the plotter 4 at an appropriate timing and recorded.

If the result of the judgment 205 is YES, the first byte of data immediately after the delimiter COD, that is, the storage address information ADD of the memory table, is set to variable 1 (207), and the 2 bytes immediately after the delimiter CDD are processed. The eye data, that is, the consecutive number, is set to a counter k, and the value obtained by subtracting 1 from the consecutive number is set to a correction value i (process 208
).

Then, in the continuous line memory 7, the memory address information A corresponding to the value of the variable 1 is stored in the memory table corresponding to the number of pages notified from the system control unit 9 at that time.
The run length code for one line stored in the line memory LM of the DD is read out, decoded into original image information, and the image information is stored in the buffer 5 via the pass line 3 (processing 209). .

Then, this process 209 is repeatedly executed while decrementing the counter k (process 210) until the value of this counter becomes O (until the result of judgment 211 becomes NO). As a result, image information having the same content is repeatedly decoded for the number of consecutive lines.

When the output of this continuous image information is finished, the correction value j is added to the counter n to correctly correct the number of processed lines (step 212), and the process returns to step 202.

The above process is repeatedly executed, and when it is determined in judgment 203 that the decoding process for one page has been completed, this process is terminated, and the system also indicates that the decoding process for one page has been completed. The control unit 9 is notified.

As a result, the system control unit 9 instructs the encoding/decoding unit 6 to decode the second document if the subsequent received information is stored in the page memory 8.

Therefore, the above-described encoding process is repeatedly executed, and at this time, the memory table in the continuous line memory 7 that corresponds to the second transmission document is selected.

The above operations are sequentially and repeatedly executed until all the information stored in the page memory 8 is decoded.

Note that the system control unit 9 is notified of the size of the document to be transmitted in the transmission control procedure from the sending terminal side, and the system control unit 9 notifies the encoding/decoding unit 6 of this size information in advance. ing.

As a result, the total number of lines corresponding to this size information is used as the criterion for determining the end of a page in the process 203 described above.

In this way, the received information stored in the continuous line memory 7 and the page memory 8 is decoded into the original image information, and the plotter 4 records and outputs the original image information. Note that, as a matter of course, this decoded image information is stored in the page memory 8.
It can also be stored again in the free space.

As mentioned above, when the same run-length encoded data for one line continues, the run-length encoded data is collectively encoded to make it shorter, so for example,
As shown in FIG. 6, the margin area A formed on the document DD
Alternatively, a blank part B or a blank part in a part C where vertical and horizontal ruled lines are drawn is converted into a very short code.

In particular, in the above-described facsimile machine, since the calligraphic information used as a transmission document has relatively many margins and blank spaces, the present invention has a great effect in reducing the transmission time.

In the above embodiment, the counter m that stores the number of lines with the same content is set to 1 byte, so the number of consecutive lines can only be managed up to 256. However, by setting the value of the counter m appropriately, this can be managed. The number of consecutive sequences that can be managed can be increased. Furthermore, if the number of consecutive sequences is greater than 256, the above-mentioned encoding process may be used, and if the number of consecutive sequences exceeds 256, the same encoding process may be repeatedly executed.

Similarly, storage address information AD in the line table
By increasing the number of digits of D, similar encoding processing can be performed on more consecutive parts of the same content.

In the above-described embodiment, the present invention is applied to a facsimile machine, but the present invention can be similarly applied to other devices such as an image file system.

[Effect] As explained above, according to the present invention, run-length codes are compared for each main scanning line, and when main scanning lines with the same content are consecutive, the run-length code of the immediately preceding main scanning line is compared. After placing a predetermined delimiter code immediately after , information representing the consecutive number and the content of the run-length code in the main scanning line is output instead of a 2-run length code, so the code of the continuous part This has the advantage that the length of is significantly shortened and the coding rate can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a facsimile apparatus according to an embodiment of the present invention, FIG. 2 is a signal arrangement diagram showing an example of a line table, FIG. 3 is a flowchart showing an example of encoding processing, and FIG. FIG. 4 is a flowchart showing an example of decoding processing, FIG. 5 is a signal arrangement diagram showing an example of encoded data, and FIG. 6 is a plan view showing an example of a document. 6... Encoding/decoding unit, 7... Continuous line memory,
8...Page memory. r' ・＼5 Agent Patent Attorney Crest 1) Makoto, Somata Figure 3

Claims (2)

[Claims] (1) The image information output from the image reading device is sequentially converted into run-leg codes, and the run-leg codes are compared in units of main scanning lines. When main scanning lines with the same content are consecutive, the immediately preceding consecutive main scanning lines are A feature is that after placing a predetermined delimiter code immediately after the run-length code of the main scanning line, information representing the number of consecutive delimiters and the content of the run-length code in the main scanning line is output instead of the run-length code. An encoding method for image information. (2) In claim 1, the encoded image information is stored in a first storage means, and
An image information encoding method characterized in that the information representing the content of the run-length code is information corresponding to a storage address of the run-length code in a second storage means that stores the run-length code.