JP3175566B2 - Facsimile image data processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing facsimile image data communicated via a line.

[0002]

2. Description of the Related Art Generally, in a facsimile apparatus, when an image is stored in a memory, the image is compressed by an encoding method called an MH method or an MR method, and the image is compressed and stored in the memory. FIG. 5 is a diagram showing an example of image compression by the MH encoding method, in which one line of image dots is input, and the number of white and black dots is sequentially counted to perform encoding. That is, for example, if two whites are consecutive, "011
In this case, coded data “1” is generated, and then coded data “10” is generated if three blacks are consecutive.
The white and black of the eight dots are sequentially determined and stored in the memory as image data. When the EOL signal shown in FIG. 5 indicating the end of one line is detected, the white and black of each dot of the next line are similarly determined to generate encoded data, which is stored in the memory as image data.

[0003]

As described above, when the black and white of image dots are sequentially determined and encoding is performed in accordance with the number,
For example, when a halftone image in which white and black alternate alternately by one dot is encoded, the encoded image data is not compressed, and the encoded image data is not compressed but is divided into four (1728) image dots before encoding.
There was a problem that doubled. Accordingly, an object of the present invention is to improve the compression efficiency when such a halftone image is compressed.

[0004]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a halftone image read by a sensor .
An image dot corresponding to the image is generated as image data, and when a predetermined number of image dots having a value of "0" are continuously detected in the image dots, a dot having a value of "1" is added after the predetermined number of dots. To indicate the end of one line
This is a method for generating image data different from a signal and an RTC signal indicating the end of one page. Therefore, since image dots are generated as image data as they are,
It is possible to improve the compression efficiency when compressing a halftone image in which white and black alternately change by several dots at the same time, and at this time, it becomes possible to distinguish between an EOL signal and an RTC signal. . When transmitting the generated image data and receiving the image data, a dot of a value "1" following a predetermined number of dots of a value "0" is detected and the dot of the value "1" is deleted. It is a way to do it. Therefore, image data in which image dots are generated and transmitted as they are can be accurately received.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a facsimile apparatus according to the present invention. In the figure, 1 is a CPU for controlling the entire apparatus, 2 is a line such as a telephone line, 3
Is a DP generating circuit for generating a DP (dial pulse) signal to be transmitted to the line 2, 4 is a modem for transmitting and receiving facsimile information, 5 is an incoming call detecting circuit, 6 is a ringer sound generating circuit for generating a 16 Hz tone, and 7 is a hook. Switch.
Reference numeral 8 denotes an image sensor for reading information of a set original, 9 a thermal head for recording received image data on recording paper, 10 a dial key, 11 a communication key for starting facsimile communication, and 12 a reception key. Memory for storing image data to be transmitted or image data to be transmitted, 1
3 is a display circuit, 14 is a speaker. Also, 15-1
7 is a contact, 18 is a transformer, and 19 is a built-in telephone.
The built-in telephone 19 includes a contact 20, a ringer 21, a communication circuit 22, and a handset 23 that are interlocked with the operation of the hook switch 7.

The facsimile apparatus is capable of automatically switching between a call mode and a facsimile mode.
Are switched to the b side, and the contact 17 is switched to the a side. In this case, when an incoming signal arrives from the line 2, it is sent to the built-in telephone 19 via the contacts 15 to 17, and the ringer 31 of the built-in telephone 19 rings. And built-in phone 1
By the off-hook of No. 9, the contact 20 is switched to the a side, and a call with the other party becomes possible. When an incoming signal arrives from the line 2 in the facsimile mode, the incoming signal is detected by the incoming detection circuit 5 and notified to the CPU 1. CPU
Upon receiving the notification of the incoming call, 1 switches the contact 16 to the a side to respond to the incoming call, and receives image data from the partner device via the modem 4.

When performing facsimile transmission in the facsimile mode, an original is set and the dial key 10 is operated. Then, this is stored in a predetermined area of the memory 12 as a dial number, and when the communication key 11 is subsequently pressed, the contacts 15 and 16 are switched to the a side to capture the line and to store the dial number. A dial signal is transmitted from the DP generation circuit 3 to the line 2 based on the number. When the partner device responds, the contact 15 is switched to the b side, and the image data read from the document and stored in the memory 12 is transmitted to the modem 4 and transmitted to the partner device via the line 2.

In such a facsimile apparatus, when an image read by the image sensor 8 is encoded and stored in the memory 12, a halftone image in which white and black alternately change every several dots among the read image dots. In this case, for example, even if coding and compression are performed by the MH coding method which is usually performed, the amount of the coded data is several times larger than the original image dot, and the compression becomes impossible, and the capacity of the memory 12 is reduced. There is a problem that encoded data cannot be stored unless the number increases. Therefore, when such a halftone mode image is stored in the memory 12, the image dot itself is stored without being encoded.

FIG. 2 is a flow chart showing the operation of the main part of such a facsimile apparatus. The output of the image sensor 8 for reading the document information is stored in the memory 12 as image data and the stored image data is transmitted.
It shows the operation of PU1. That is, the CPU 1 first sets the registers m and n to "0" (step S1).
And the register n is incremented by one (step S2), and the image dot read by the image sensor 8 is "0".
(White) is determined (step S3). If it is "0", the value of the register m is added (step S4).

Subsequently, it is determined whether or not the value of the register m is "10" (step S5). If the value of the register m is less than "10", the white dots are stored in the memory 12, and the process proceeds to step S9. If the image data is “1” (black) (“N” in step S3), the value of the register m is set to “0” (step S3).
8) Similarly, this black dot is stored in the memory 12.

Here, the number of continuous white dots read and output by the image sensor 8 is counted as 10 consecutive steps, and step S
When the determination of 5 is "Y", "1" is added to the image data from the image sensor 8 and stored in the memory 12 (step S6), and the value of the register m is set to "0" (step S7). . Thus, the number of white dots in the image is 10
When the number is counted, “1” is added and stored, so that an actual image dot and “1” are added after 11 bits of “0” continue for 11 bits shown in FIG. Line end signal) and an RTC signal to be described later.

Thereafter, the flow shifts to step S9, where it is determined whether or not one line has ended based on the value of the register n indicating the number of processed image dots. Here, the count value of one line is “1728” in the case of the A4 size, and “2728” in the case of the B4 size.
048 ". If the processing of the image of one line is not completed, the process returns to step S2 to add the value of the register n, and in step S3, the monochrome determination of the next image dot on the same line output from the image sensor 8 is similarly performed. . When the one-line image processing is completed, the EOL signal is added to the image data already stored in the memory 12 and stored (step S10).

Then, it is determined in step S11 whether or not the processing of the image dots for one page has been completed. If the processing of the image dots for one page has not been completed, the flow returns to step S1 to return to the registers m and n. Is set to “0”, and the image of the next line is processed similarly. When the processing of the image dots for one page is completed, an RTC signal corresponding to the five EOL signals described above is added to the image data stored in the memory 12 (step S12). Is completed. When processing the image dots of the next page, the process returns to step S1 and is performed in the same manner.

The image data thus stored in the memory 12 is sequentially read from the memory 12 and transmitted to the partner device via the modem 4. As a result, when compressing halftone image data in which white and black alternately change every several dots, the number of data can be significantly reduced as compared with the case of compressing with a normal encoding method. Therefore, the memory 12
Can be reduced, and the transmission time of image data can be shortened.

FIG. 3 is a flowchart showing a process of receiving image data transmitted in such a compressed manner.
That is, in this case, the CPU 1 first sets both the values of the registers m and n to "0" (step S21). Next, the value of the register n is incremented by one (step S22), and subsequently, it is determined whether or not the image data received via the modem 4 is "0" (white) (step S23). If it is "0", the value of the register m is added (step S24).

Subsequently, it is determined whether or not the value of the register m is "10" (step S25). If the value of the register m is less than "10", the white dot data is stored in the memory 12, and the process proceeds to step S30.
If the received image data is "1" (black) ("N" in step S23), the value of the register m is set to "0" (step S29), and the black dot data is similarly set. It is stored in the memory 12.

If the number of continuous white dots in the received image dot data is 10 and the determination in step S25 is "Y", the white dot data is stored in the memory 12 while the next received image is stored. It is determined whether or not the data dot is "1" (step S26). If the data dot is "1", the dot data is invalidated (step S27), and the value of the register m is set to "0" (step S28). S3
Move to 0. If the number of white dots in the received image counts ten consecutively and “1” is received next as data, this data is data added from the transmission side and is not actual image data. Perform invalidation processing.

Thereafter, in step S30, the register n
It is determined whether reception of one line has been completed based on the value of. If the reception processing of the image of one line is not completed, the process returns to step S22 to add the value of the register n, and the black and white determination of the next image dot of the same line received in step S23 is similarly performed. When the one-line image receiving process is completed, it is determined whether or not the EOL signal has been received (step S31). If the EOL signal can be received normally, then whether or not the RTC signal indicating the transmission of one page of image data has been received. Is determined (step S32).

If the RTC signal cannot be received,
Returning to step S21, the values of the registers m and n are set to "0", and the black and white judgment of the image data of the next page is started. Also,
Although the value of the register n indicates the number of image dots for one line and the determination in step S30 is "Y",
If the OL signal cannot be received, the received data of that line is invalidated (step S33), and the process returns to step S21 to receive the image data of the same line again.

In this manner, transmission and reception can be performed with the dot data as it is without encoding the image. Therefore, when communicating halftone image data in which white and black alternately change every few dots, the communication time is greatly reduced as compared with the case of communicating data encoded by the normal encoding method. it can.

In the description of FIGS. 2 and 3, an example of the software processing by executing the program of the CPU 1 has been described. However, it is also possible to realize the processing by hardware using each unit having the configuration shown in FIG. That is, as shown in FIG. 4A, the image dot data read by the image sensor 8 is
When ten consecutive “0” s are detected by the “0” detection unit 41, “1” is added by the “1” addition unit 42 and is provided to the bit addition unit 43. The bit addition unit 43 sets the value of “1” from the bit addition unit 42 to 1 for the input image data.
Add a bit. Then, the bit addition unit 43
The EOL signal added by the detection of the end of processing of one line from the L signal adding unit 44 is added to the last bit of the one line, and the RTC signal is detected by the RTC signal adding unit 45 by detecting the end of processing of one page of image data. A signal is added to the end of the image data of one page to generate image data of one page and stored in the memory 12.

A receiving section for receiving the image data generated and transmitted in this manner can be configured as shown in FIG. That is, when “1” is detected after 10 consecutive “0s” are detected by the “1” detection unit 51 from the image data received by the modem 4, the “1” is deleted by the “1” deletion unit 52. Is deleted and given to the bit deletion unit 53. The bit deletion unit 53 deletes one bit of the value “1” from the received image data from the bit deletion unit 52. Also, E
When detecting the EOL signal from the received image data, the OL signal detector 54 outputs a one-line end signal. Also,
The RTC signal detection unit 55 detects the RTC signal from the received image data.
When a signal is detected, an end signal for one page is output. further,
When the count value of the number of image dots by the counter or the like reaches a predetermined value, the one-line number detection unit 56 outputs a one-line detection signal. With the components configured as described above, image data transmitted as it is without encoding image dots can be accurately received.

[0023]

As described above, according to the present invention, an image dot corresponding to a halftone image read by a sensor is generated as image data, and an image dot having a value "0" among the image dots is generated. Are continuously detected by a predetermined number, a dot of value "1" is added after the predetermined number of dots, and the image data is different from the EOL signal indicating the end of one line and the RTC signal indicating the end of one page. Because the image dots are generated as they are, the image dots are directly generated as image data, so that it is possible to improve the compression efficiency when compressing a halftone image in which white and black alternate alternately by several dots. At this time, it is possible to distinguish the EOL signal or the RTC signal. When transmitting the generated image data and receiving the image data, a dot of a value "1" following a predetermined number of dots of a value "0" is detected and the dot of the value "1" is deleted. Thus, the image data that is generated and transmitted as it is can be accurately received.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a facsimile apparatus according to the present invention.

FIG. 2 is a flowchart showing an operation of a main part of the apparatus.

FIG. 3 is a flowchart showing an operation of a main part of the apparatus.

FIG. 4 is a block diagram illustrating an example in which a main part of the device is configured by hardware.

FIG. 5 is a diagram illustrating an example of image encoding generally performed in a facsimile apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... line, 3 ... DP generation circuit, 4 ... Modem, 8 ... Image sensor, 9 ... Thermal head, 10 ...
Dial key, 11 communication key, 12 memory, 41 ...
"0" detection unit, 42 ... "1" addition unit, 43 ... bit addition unit, 44 ... EOL signal addition unit, 45 ... RTC signal addition unit, 51 ... "1" detection unit, 52 ... "1" deletion unit, 53 ...
Bit deletion unit, 54 ... RTC signal detection unit, 55 ... RTC
Signal detector, 56... 1 line detector.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/41-1/419

Claims (2)

(57) [Claims] 1. A facsimile apparatus for performing the images communications halftone, generates the image dots corresponding to the halftone image read by the sensor as an image picture data, the value "0 in the image dot When a predetermined number of image dots are detected consecutively, a dot of value "1" is added after the predetermined number of dots, and an EOL signal indicating the end of one line and an RTC signal indicating the end of one page are added. Generating a different facsimile image data. 2. The method according to claim 1, wherein when the generated image data is transmitted, when the image data is received, a dot of a value “1” following a dot of the predetermined number of values “0” is detected. A facsimile image data processing method, wherein a dot with a lever value "1" is deleted.