JPH06326855A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To change over a line density in one and same page properly, to reduce a data quantity and to obtain a beautiful picture by decreasing vertical resolution of picture data of a line so as to store the resulting picture data when inversion of picture element is less than a specified value. CONSTITUTION:A bit change in data of a line of picture data (raw data before passing through a coding/decoding section 7) read from a scanner 3 of a facsimile equipment in a vertical resolution of 400dpi is detected to calculate a ratio of change in picture element inversion. Then the rate of change is compared with each specified rate in 400, 300, 200 and 100dpi and when the rate of change is lower than the specified value, thinning processing of picture data is executed and after number of lines is decreased, the result is coded and stored in a picture memory 6 and the vertical resolution information for each line is stored in the unit of pages. The picture data thinning processing is executed by the method implemented by a facsimile equipment or a copying machine in general.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine, and more particularly, it can be applied to a technique for editing / storing image data in a facsimile machine, and in particular, it can perform linear density switching within the same page. The present invention relates to a facsimile device capable of reducing data amount and obtaining beautiful image data.

[0002]

2. Description of the Related Art In a conventional facsimile apparatus, when editing / storing image data, OR processing (thinning-out) for reducing the image data is performed, or two originals are made into one to reduce the image coarseness and then transmitted. It is known that editing processing such as

[0003]

However, since the conventional facsimile apparatus as described above does not have the function of switching the linear density within the same page, even if the original is complicated only in a part, the same linear density is obtained. As a result, if the image coarseness is increased, it becomes difficult to see, and if the image coarseness is increased, the amount of image data is increased overall and the communication time Therefore, there is a problem that the communication cost increases.

Therefore, as a conventional technique for solving the above-mentioned problem, there is a main scanning line density switching type facsimile apparatus reported in, for example, Japanese Patent Application Laid-Open No. 62-185460, in which the image information density of the original image is It is possible to compress and reduce the amount of information in the main scanning direction of the original by configuring the main scanning line density to be switched appropriately according to the height, but no mention is made of the means that is a characteristic part of the present invention.
It was a completely different method.

Therefore, according to the present invention, it is possible to reduce the amount of data by switching the linear density within the same page, obtain clear image data, and efficiently generate an original having a complicated part. It is an object of the present invention to provide a facsimile apparatus that can be transmitted and can shorten communication time and communication cost.

[0006]

The invention according to claim 1 is
An image data reading unit that reads image data, a bit change detection unit that detects a bit change of the image data read by the image data reading unit, and a bit change of the image data by the bit change detection unit, and pixel inversion is performed. When the number is smaller than the specified value, the image data storage unit stores the image data by reducing the vertical resolution of the image data of the line, and the vertical resolution information storage unit stores the vertical resolution information of each line. To do.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a transmitting section for transmitting the vertical resolution information stored in the vertical resolution information storage section to a receiving terminal. . According to a third aspect of the present invention, in the first and second aspects of the present invention, a receiving unit that receives the vertical resolution information transmitted by the transmitting unit, and vertical resolution information that stores the vertical resolution information received by the receiving unit. It is characterized by having a storage section and an image data reproducing section for reproducing the received image data based on the vertical resolution information received by the receiving section.

[0008]

According to the present invention, the image data is read by the image data reading unit, the bit change of the image data read by the image data reading unit is detected by the bit change detection unit, and the pixel inversion is higher than the specified value. When the number is small, the vertical resolution of the image data of the line can be reduced and the image data can be stored in the image data storage unit, and the vertical resolution information of each line can be stored in the vertical resolution information storage unit.

Therefore, the line density can be appropriately switched within the same page, so that the amount of data can be reduced and beautiful image data can be obtained. Therefore, a complicated original document can be efficiently transmitted only in a certain portion, that is, a portion with few pixel changes can be transmitted with a low resolution, and a portion with many pixel changes can be transmitted with a high resolution. The communication time can be shortened and the communication cost can be reduced as compared with the case where all the parts are transmitted with high resolution.

According to a second aspect of the present invention, in the first aspect of the invention, the vertical resolution information stored in the vertical resolution information storage section can be transmitted to the receiving terminal by the transmitting section. Therefore, the effect of the invention described in claim 1 can be efficiently obtained. According to the invention of claim 3,
In the invention described in claims 1 and 2, the vertical resolution information transmitted by the transmitting unit is received by the receiving unit, the vertical resolution information received by the receiving unit is stored in the vertical resolution information storage unit, and the receiving unit receives the vertical resolution information. The received image data can be reproduced by the image data reproducing unit based on the received vertical resolution information. Therefore, the amount of image data can be made smaller than that of a normally transmitted document, and the amount of image memory used can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a facsimile apparatus according to an embodiment of the present invention. In FIG. 1, 1
Is a system control unit for executing the control processing of the entire facsimile apparatus, 2 is an operation display section including various operation keys for operating the facsimile apparatus and an LCD, and 3 is a scanner for reading a document at a predetermined resolution. And 4 is a plotter for recording the image data of the image memory 6. Next, 5 is a memory for storing the control processing program, various data, unique information, etc.
Is for accumulating the image data encoded and compressed by the encoding / decoding unit 7. The encoding / decoding unit 7 is for encoding / compressing the image data and decoding the original image data. Yes, 8 is a communication control unit that controls communication with the network via the ISDN / PSTN I / F (interface) unit 9. Note that each of these blocks uses the system bus 10
Data is exchanged between the blocks mainly via the system bus 10.

Next, FIG. 2 is a diagram showing a communication procedure used in this embodiment, FIG. 2 (a) shows a communication procedure at the time of G4 communication, and FIG. 2 (b) shows a communication procedure at the time of G3 communication. The communication procedure is shown. The G4 and G3 communications here are normal G
4, the same as G3 communication. The function confirmation of whether or not the line density is switched in the same page for each of G4 and G3 communication is performed as follows. In G4 communication, CSS (session start command), RSSP (session start positive response),
CDCL (Document function list command) and RD
Performed by SUD (session user data) added to CLP (document function list affirmative response),
On the other hand, in G3 communication, NSF (non-standard function) and NSS
(Non-standard function setting).

The vertical resolution information of each of the G4 and G3 communications is notified as follows. In G4 communication, it is added to the SUD of the CDS (Document Start Command) and notified, while
In G3 communication, NSS (non-standard function setting) is added and notified. Next, FIG. 3 is a diagram showing the configuration of a linear density conversion table for managing the linear density switching according to this embodiment.
Each information is used for the following purposes.

The range is used to specify the number of pixels used for the determination of the specified value in one line. For example, if 100 is specified, it is determined how many pixel inversions occur in 100 pixels. The stipulated value is used to specify how many times the pixel inversion is performed within the number of pixels specified by the range to process with the corresponding vertical resolution. For example, if the specified value 10 is specified in the range 100, when "10> number of inversions", processing is performed with the corresponding vertical resolution. The resolution is the vertical resolution (400 dpi, 300 dpi, 200 dpi, 1
00 dpi). As for the number of unconverted lines, if the number of lines exceeding the specified value is smaller than this line number, resolution conversion is not performed. This setting of the number of lines is used to prevent frequent resolution conversion.

If there are 50 or more lines with a pixel change amount of 10 or less in 100 pixels, the resolution is 100 dp.
If the number of lines in which the pixel variation amount is 20 or less in 100 pixels is 40 lines or more, the processing is performed at a resolution of 200 dpi. For example, assuming that the range is 100 and the specified value is 20, the following processing is performed. A with a horizontal resolution of 200 dpi
For 4 manuscripts, the number of pixels is 1728 (CCITT recommended value)
Is. The number of changes for each 100 pixels from the beginning of this number of pixels is calculated, and the value with the largest number of changes among the calculated number of changes for each 100 pixels is compared with the specified value 20,
If the number of changes is less than the specified value, processing is performed at the corresponding resolution. However, when the number of non-conversion lines is specified, the above process is repeated until the number of lines equal to or more than the number of lines is found, and only when the number of non-conversion lines is exceeded, the process is performed with the corresponding resolution.

Next, FIG. 4 is a diagram showing a structure of vertical resolution information according to the present embodiment. One piece of information is composed of 2-bit resolution information and a value indicating the number of lines of that resolution,
As shown in FIG. 3 described above, the result of resolution conversion is set in the vertical resolution information. Thinning and reproduction of image data are performed by a method generally used in a facsimile, a copying machine or the like.

Next, FIGS. 5 and 6 are flowcharts showing the flow of vertical resolution information creation according to this embodiment. The document transmitting side creates and transmits information according to this flow, while the receiving side receives this information and reproduces the image data while referring to the designated resolution and the number of lines of that resolution. Specifically, first, the raw data of the first line is read (process P ₁ ), the number of changes is calculated by the number of pixels specified by the range, and the largest number A of changes in one line is saved (process P ₂ ), the saved number of changes A is compared with a specified value, and a resolution B equal to or less than the specified value is found and saved (process P ₃ ). Next, after saving the number of unconverted lines C pointed to by the saved resolution B (process P ₄ ), clearing the update reservation flag D (process P ₅ ), and if there is data for the next line (process P ₆ ), , The raw data of the next line is read (process P ₇ ), while if there is no data of the next line (process P ₆ ), the process ends.

Then, after reading the raw data of the next line,
Calculate the number of changes with the number of pixels specified in the range, and within one line
Save the largest number of changes E (process P₈), This
The number of changes E is compared with the specified value, and the resolution is less than the specified value.
After finding and saving F (Process P₉), Save this
Save the number of unconverted lines G indicated by the resolution E (process
P_Ten). Next, if the resolution F = the number of changes A (process P
₁₁), The number of unconverted lines C = the number of unconverted lines C-1 (however,
However, if the number of unconverted lines C = 0, do not set to -1)
(Process P₁₂), Update reservation flag when the number of unconverted lines C = 0
Is not 0 (Process P_13,P₁₄) Is the update reservation flag
Clear D (Process P₁₅), Raw day of the line so far
After encoding the data at resolution B and storing it in the image memory 6,
(Process P₁₆), The number of unconverted lines for updating the resolution B with F
Update C with G (Process P₁₇), Process P ₆Go back and up again
The same process as described above is repeated.

If the resolution F is not the number of changes A (process P ₁₇ ), the raw data of the lines up to this point are encoded with the resolution B and stored in the image memory 6 (process P ₁₈ ), and the number of unconverted lines C = If it is 0 (process P ₁₉ ), the number of unconverted lines C for updating the resolution B with F is updated with G (process P ₂₀ ), and the process returns to process P ₆ . On the other hand, the number of unconverted lines C = 0
If not (process P ₁₉ ), after setting the update reservation flag D (process P ₂₀ ), the process returns to process P ₆ . When the number of non-converted lines C is not 0 (process P ₁₃ ), the update reservation flag = 0
If so (process P ₁₄ ), the process returns to process P ₅ .

As described above, in this embodiment, the bit change of the 1-line data of the image data (raw data before passing through the encoding / decoding unit 7) read from the scanner device 3 at the vertical resolution of 400 dpi is detected, and the pixel is detected. The change rate of inversion is calculated, and the change rate is set to 400 dpi, 300 dpi, 200 dpi.
i and 100 dpi respectively, and when it is lower than the specified value, the image data is thinned out, the number of lines is reduced, and then encoded and stored in the image memory 6. An area for storing resolution information is provided,
This information is transmitted to the receiving terminal before transmitting the image data. The image data thinning-out process is performed by a method generally used in a facsimile, a copying machine, or the like.

Therefore, since the line density can be appropriately switched within the same page, the amount of data can be reduced and beautiful image data can be obtained. Therefore, a complicated original document can be efficiently transmitted only in a certain portion, that is, a portion with few pixel changes can be transmitted with a low resolution, and a portion with many pixel changes can be transmitted with a high resolution. The communication time can be shortened and the communication cost can be reduced as compared with the case where all the parts are transmitted with high resolution.

Further, in this embodiment, in the receiving terminal,
If it is specified in the function confirmation at the start of communication that line density switching within the same page is specified, the vertical resolution information that is created and transmitted is received and stored in the memory of the local terminal, and the stored vertical resolution information is referenced. While it is configured to reproduce the received image data. The reproduction processing of the image data is performed by a method generally used in a facsimile machine, a copying machine, or the like. Therefore, the amount of image data can be made smaller than that of a normally transmitted document, and the amount of image memory used can be reduced.

[0023]

According to the present invention, it is possible to reduce the amount of data by switching the linear density within the same page, to obtain clear image data, and to copy even a part of a complicated document. There is an effect that the data can be efficiently transmitted, the communication time can be shortened, and the communication cost can be reduced.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a communication procedure flow according to an embodiment of the present invention.

FIG. 3 is a diagram showing a linear density conversion table according to an embodiment of the present invention.

FIG. 4 is a diagram showing vertical resolution information according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a vertical resolution information creation flow according to an embodiment of the present invention.

FIG. 6 is a flowchart showing a vertical resolution information creation flow according to an embodiment of the present invention.

[Explanation of symbols]

 1 System Control Section 2 Operation Display Section 3 Scanner 4 Plotter 5 Memory 6 Image Memory 7 Encoding / Decoding Section 8 Communication Control Section 9 I / F Section 10 System Bus

Claims (3)

[Claims] 1. An image data reading section for reading image data, a bit change detecting section for detecting a bit change in the image data read by the image data reading section, and a bit change for the image data in the bit change detecting section. When the pixel inversion is less than the specified value, the image data storage unit that stores the image data by reducing the vertical resolution of the image data of that line and the vertical resolution information storage unit that stores the vertical resolution information of each line are provided. A facsimile machine characterized by having. 2. The facsimile apparatus according to claim 1, further comprising a transmitting unit for transmitting the vertical resolution information stored in the vertical resolution information storage unit to a receiving terminal. 3. A receiving unit for receiving the vertical resolution information transmitted by the transmitting unit, a vertical resolution information storage unit for storing the vertical resolution information received by the receiving unit, and a vertical resolution information received by the receiving unit. 3. The facsimile apparatus according to claim 1, further comprising: an image data reproducing unit that reproduces the received image data based on the received image data.