JP2000253237A - Facsimile machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a facsimile machine capable of suppressing the degradation of picture quality in reduction as much as possible. SOLUTION: Since a line whose content is similar to a former line is selected as a line thinned in a reduction processing in an auxiliary scanning direction, and effect that the degradation of the picture quality of a picture after reduction can be held utmost is obtained. Since there are many areas where whole white lines are continued in the document picture which is frequently used as a facsimile original, the whole white lines are thinned. Thus contents of the facsimile original desired to transmission by a transmission user is hardly impaired and the very satisfactory reduced picture can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
The present invention relates to a facsimile machine that creates reduced image data by thinning out lines of data of one line for each predetermined number of lines of original image data.

[0002]

2. Description of the Related Art In a facsimile apparatus, when transmitting image information,
Based on the receiving capability received from the partner terminal, the size of the image information receivable by the partner terminal is determined, and if the receivable size is smaller than the size of the transmitted image, a reduction ratio based on the size ratio is used. The image information is reduced, and the image information of the reduced image obtained thereby is transmitted.

When the received image information is longer than the recording paper size provided in the terminal, the image is reduced in the sub-scanning direction so that the received image information can be appropriately recorded on the recording paper. .

[0004] In such image reduction processing, image reduction processing in the sub-scanning direction is realized by thinning out one line of image at intervals of the number of lines corresponding to the reduction ratio.

[0005]

However, in such a conventional image reduction method, since one line of the image is forcibly thinned out at regular intervals, for example, horizontal lines of characters disappear. This causes a problem that image quality is severely deteriorated.

The present invention has been made in view of the above circumstances, and has as its object to provide a facsimile apparatus capable of minimizing image quality degradation at the time of reduction.

[0007]

According to the present invention, there is provided a facsimile apparatus for generating reduced image data by thinning one line of data from original image data every predetermined number of lines in accordance with a reduction ratio. When the contents of two consecutive lines are the same, one of the lines is thinned as a thinned line. In addition, the continuous 2
The means for comparing the contents of the two lines is provided in the encoding / decoding means for the image data.

Further, in a facsimile apparatus for thinning out one line of data for every predetermined number of lines of original image data in accordance with the reduction ratio and creating reduced image data, the above-mentioned predetermined number of lines may be used. Next, the same ratio of the contents of two consecutive lines is calculated, and the line having the highest same ratio is thinned out as a thinned line. The means for comparing the contents of the two consecutive lines is provided in the encoding / decoding means for the image data.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in detail.

FIG. 1 shows a group 3 facsimile apparatus according to an embodiment of the present invention.

In FIG. 1, a system control unit 1 performs control processing of each unit of the facsimile apparatus, facsimile transmission control procedure processing, and data transfer control (such as DMA).
Is a control processing program executed by the system control unit 1,
In addition to storing various data required when executing the processing program, it constitutes a work area of the system control unit 1 and includes a parameter memory 3.
Is for storing various information unique to this group 3 facsimile apparatus, and the clock circuit 4 is for outputting current time information.

The scanner 5 is for reading a document image at a predetermined resolution, the plotter 6 is for recording and outputting an image at a predetermined resolution, and the operation display unit 7 is a facsimile apparatus. To operate,
It consists of various operation keys and various indicators.

The encoding / decoding section 8 encodes and compresses the image signal and decodes the encoded and compressed image information into the original image signal.
This is for storing a large number of image information in a coded and compressed state.

The group 3 facsimile modem 10 is for realizing a group 3 facsimile modem function, and is a low-speed modem function (V.21 modem) for exchanging transmission procedure signals and mainly exchanging image information. High-speed modem function (V.17 modem,
V. 34 modem, V.34. 29 modem, V.29. 27ter modem etc.).

The network control device 11 is for connecting the facsimile machine to a public telephone line network and has an automatic transmission / reception function.

The system control unit 1, system memory 2, parameter memory 3, clock circuit 4, scanner 5, plotter 6, operation display unit 7, encoding / decoding unit 8, image storage device 9, group 3 facsimile modem The network controller 10 and the network controller 11 are connected to an internal bus 12, and data exchange between these elements is mainly performed through the internal bus 12.

Data exchange between the network controller 11 and the group 3 facsimile modem 10 is directly performed.

In this embodiment, when an image is reduced in the sub-scanning direction, the processing shown in FIGS. 2 and 3 is executed. The reduction ratio in this case is 90% for simplicity.
Is set to That is, in this case, the image data is thinned out at a ratio of one line to ten lines. The processing target in this case is the encoded and compressed image information data stored in the image storage device 9.

First, "0 (reset)" is set in a flag A for storing that a line has been thinned out, a counter N for storing the number of lines to be processed is set to 0, and a flag A and a counter N are set. The value is initialized (process 101), the image information data of the image to be processed is decoded for one line, and image data for one line is formed (process 10).
2).

At that time, the value of the flag A is set to "1".
(Set) "(judgment 10
3) If the result of determination 103 is NO, process 1
The image data for one line decoded in 02 is compared with the image data for the previous line (process 104). At this time, in the case of the first line of the first page, an all white line is used as the image data of the previous line.

At this time, it is determined whether or not the two lines compared in the process 104 are the same (determination 105). If the result of the determination 105 is YES, the image data of the line to be processed at that time is determined. Delete (Process 10
6) The value "1" indicating that the line has been thinned is set in the flag A (step 107), and it is checked whether the processing for one page has been completed at that time (decision 108).
When the result of the determination 108 is NO, the process returns to the process 102, and the same process is executed for the next line. When the result of determination 108 is YES, this process ends.

When the result of the judgment 105 is NO, it is checked whether or not the value of the counter N is equal to "10" (decision 109). If the result of the determination 109 is YES, there is no continuous identical line in the 10 lines of the thinning unit, so the image data of the 10th line to be processed at that time is deleted (step 11
0), the value of the counter N is cleared to “0” (process 111), the value of the flag A is cleared to “0” (process 112), and the process proceeds to the judgment 108, at which time one page worth of data is read. Check whether the processing has been completed and execute the subsequent processing.

When the result of the determination 109 is NO, the value of the counter N is increased by one (process 113), and the data of one line to be processed at that time is encoded (process 114). The process shifts to decision 108 to check whether or not the processing for one page has been completed at that time, and executes the subsequent processing.

When the result of the judgment 103 is YES, the value of the counter N is increased by one (step 115).
One line of data to be processed at that time is encoded (processing 116), and it is checked whether the value of the counter N at that time is "10" (determination 117).
When the result of step 17 is YES, the value of the counter N is cleared to "0" (step 118) and the flag A
Is cleared to "0" (step 119), and the routine goes to the judgment 108, where it is checked whether or not the processing for one page is completed, and the subsequent processing is executed.

As described above, in the present embodiment, the line having the same content as the previous line is selected as the line to be thinned out when performing the reduction process in the sub-scanning direction. Can be suppressed as much as possible. In particular, a document image that is frequently used as a facsimile original has many areas in which all white lines are continuous.
Since all the white lines are thinned out, the contents of the facsimile original that the transmitting user desires to transmit is hardly impaired, and a very good reduced image can be obtained.

In the above-described embodiment, when the contents of two consecutive lines are exactly the same, a line is selected as a thinned line. However, when the contents of two consecutive lines are almost the same, the line is selected. The same effect can be obtained even if the line is a thinned line.

FIG. 4 shows an example of reduction processing in the sub-scanning direction in that case. The reduction ratio in this case is set to 90% for simplicity. That is, in this case, 10
Image data is thinned out at a rate of one line per line. The processing target in this case is the encoded and compressed image information data stored in the image storage device 9.

First, data of 10 lines per block as a processing unit is decoded from the image storage device 9 (processing 20).
1) The same ratio between the last line of the previous block and the image data of the first line is calculated (process 202), and the same ratio of the image data of the first line and the second line is calculated (process 203).
The same ratio of the image data of the second line and the third line is calculated (step 204), and the same ratio of the image data of the third line and the fourth line is calculated (step 205). The same rate of image data is calculated (processing 206), and 5
The same ratio between the image data of the line and the sixth line is calculated (process 207), and the same ratio of the image data of the sixth line and the seventh line is calculated (process 208). The same rate of data is calculated (processing 209), and 8
The same ratio between the image data of the line and the ninth line is calculated (process 210), and the same ratio of the image data of the ninth line and the tenth line is calculated (process 211). The image is selected, the corresponding line image is deleted (process 212), and the other nine line images are encoded and compressed (process 213).

Next, it is checked whether the processing for one page has been completed (decision 214), and the result of decision 214 is YES.
, The process returns to the process 201 to execute the process of the next block. When the result of the determination 214 is NO, this processing is ended.

As described above, in the present embodiment, as the line to be thinned out in the sub-scanning direction in one block, the line having the same ratio as that of the previous line and having the same ratio is selected. Therefore, deterioration of the image quality of the reduced image can be suppressed as much as possible.

The comparison between the al line and the immediately preceding line in each of the above-described embodiments can be realized by a comparison process using a register of the CPU. This can also be realized by using the comparator CMP. In this case, it is preferable that the comparison unit CMP is provided inside the encoding / decoding unit 8.

Referring to FIG. 3, a comparison unit CMP includes a front line register RG1 for storing one byte of image data of a line immediately before a line to be processed, and image data of a current line to be processed. Current line register RG2, previous line register RG1 for storing 1 byte
A comparison circuit CP for comparing the contents of the current line register RG2 with the contents of the current line register RG2, an adder AM for adding the comparison result output from the comparison circuit CP for one line, and an output register for outputting the addition result of the adder AM RO, previous line register RG1, current line register RG
2. It comprises a comparison circuit CP, an adder AM, and a comparison control unit CC for controlling the operation of the output register RO.

The data transfer to the previous line register RG1 and the data transfer to the current line register RG2 are performed using DMA transfer means of different channels, respectively. Also, at the timing of data transfer to the current line register RG2, the DMA transfer request signals DREQ1, DREQ
REQ2 is output. At the timing when the addition result for one line is obtained by the adder AM, an interrupt signal INT is output to notify the external means (system control unit 1) of the timing of taking in the addition result for one line.

By using such a comparison unit CMP,
A quick comparison process can be performed. Also, the comparison section CM
If P is provided inside the encoding / decoding section 8, various registers provided in the encoding / decoding section 8 can be used as the previous line register RG1 and the current line register RG2, so that the apparatus cost can be reduced. .

In each of the embodiments described above, the case where the reduction ratio for thinning out one line for every 10 lines is 90% has been described, but the present invention is similarly applied to any other reduction ratio. be able to.

[0036]

As described above, according to the present invention,
Since a line having the same content as the previous line is selected as a line to be thinned out in the sub-scanning direction in the sub-scanning process, the effect of minimizing image quality deterioration of the reduced image can be obtained. In particular, a document image often used as a facsimile original has many continuous white lines, and in this case, all white lines are thinned out, and the contents of the facsimile original that the transmitting user desires to transmit is almost completely lost. A very good reduced image can be obtained without any loss.

In addition, as the line to be thinned out in the sub-scanning direction in one block, the largest line having the same ratio as that of the previous line is selected, so that the image quality of the reduced image is The effect that deterioration can be suppressed as much as possible is also obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a group 3 facsimile apparatus according to one embodiment of the present invention.

FIG. 2 is a flowchart illustrating a part of an example of a process for reducing an image in a sub-scanning direction at a reduction ratio of 90%.

FIG. 3 is a flowchart illustrating a remaining part of an example of a process when an image is reduced in a sub-scanning direction at a reduction ratio of 90%.

FIG. 4 is a flowchart illustrating another example of processing when an image is reduced at a reduction ratio of 90% in the sub-scanning direction.

FIG. 5 is a block diagram illustrating an example of a comparison unit.

[Explanation of symbols]

 1 System control unit CMP comparison unit

Continued on front page F-term (reference) 2C062 AA27 AA52 2C087 AA03 AA18 BA03 BD06 BD10 5B057 AA11 BA02 CA02 CA06 CA12 CA16 CB02 CB06 CB12 CB16 CC02 CD07 CG01 CH01 CH08 CH11 DB01 DB05 DB08 DC02 DC32 DC36 5C076 ABB22 BAB18BAB

Claims (4)

[Claims] 1. A facsimile apparatus for generating reduced image data by thinning out one line of data from original image data every predetermined number of lines according to a reduction ratio, wherein the contents of two continuous lines are A facsimile apparatus wherein one of the lines is thinned as a thinned line when the same is used. 2. A facsimile apparatus according to claim 1, wherein said means for comparing the contents of two consecutive lines is provided in means for encoding and decoding image data. 3. A facsimile apparatus for generating reduced image data by thinning out data of one line every predetermined number of lines of original image data according to a reduction ratio, wherein the predetermined number of lines A facsimile apparatus which calculates an identical rate of the contents of two consecutive lines and thins out a line having the highest identical rate as a thinned line. 4. The facsimile apparatus according to claim 3, wherein said means for comparing the contents of two consecutive lines is provided in means for encoding and decoding image data.