JPH03219772A - Facsimile equipment having halftone picture processing function - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a facsimile machine having a halftone image processing function, and particularly to a facsimile machine having a halftone image processing function. Equipped with multiple communication methods such as G4,
The present invention also relates to a facsimile machine having a function of processing halftone images such as photographs.

(Prior Art and its Problems) Conventionally, facsimile machines that have a halftone image processing function have mainly adopted a dither pattern method as a halftone image processing method. In recent years, error diffusion methods have also come into use.

On the other hand, in addition to G3, 04 has been developed as a communication system for facsimile machines for data lines having high-speed data transfer capability (high communication speed).

Incidentally, the error diffusion method is superior to the dither pattern method in terms of image quality, and the difference is particularly significant in images containing mixed text and photographs. (With the dither pattern method, the image quality of characters is inferior in the case of mixed images.) However, with the error diffusion method, the compression rate of the encoded code is lower than with the dither pattern method, and therefore the amount of data for the transmitted image is large, so the communication time is The disadvantage is that it becomes long.

Considering the characteristics of the above two halftone image processing methods, when transmitting a halftone image, it is desirable to use the dither pattern method for the G3 method and the error diffusion method for the G4 method. However, no conventional facsimile machines have taken this into consideration.

The present invention has been made in view of the above circumstances, and is a facsimile machine having a halftone image processing function that improves image quality and communication speed by selecting an appropriate halftone image processing method according to the communication method. The purpose is to provide equipment.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a facsimile machine that is equipped with multiple types of communication methods and has multiple types of halftone image processing functions, which is used during transmission. Provided is a facsimile apparatus having a halftone image processing function, characterized in that the facsimile apparatus is provided with a selection means for selecting one of the plurality of types of halftone image processing functions according to the type of the communication method used. .

Preferably, the facsimile device is equipped with G3 and G4 communication systems, and has a halftone image processing function using a dither pattern method and an error diffusion method, and the selection means is configured such that the facsimile device communicates with the G3 communication system. When communicating using the G4 communication system, the error diffusion method is selected.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a facsimile device connected to an I5DN according to an embodiment of the present invention. This facsimile device is a device having a telephone function, and reference numeral 1 in the figure indicates a CPU 1, an Oi program ROM 102, and a RAM.
103, the central control section 1 centrally controls the entire facsimile apparatus based on a control program.

The central control unit 1 includes a reader controller 21 that controls the operation of the printer 2 that reads the original at the time of transmission, a printer controller 31 that controls the operation of the printer 3 that prints the received original data at the time of reception, and a controller for the image memory 4. An image memory controller 41 is connected to the reader 2 during transmission.
reads the transmitted original image and outputs image data. The central control unit 1 encodes the output image data, and the encoded image data is sent to an I5DN line for the G4 system or an analog telephone line for the G3 system. The image memory controller 41 compresses the transmitted image information at the time of transmission.
The received image information is transmitted to a 5DN line or an analog telephone line, and upon reception, the received image information is expanded and transferred to the printer 3.

The printer 3 has a recording mechanism section, operates in response to image data input in units of pages, that is, image data that has been composited and expanded by the central control section 1, and draws images on recording paper. The recording mechanism may be of any appropriate type, such as a thermal recording type or a laser beam type.

Transmission and reception as described above are performed via the communication controller 51 connected to the central control unit 1.

The communication controller 51 is a control unit that controls communications including facsimile communications and telephone calls.

In addition to the reader system and printer system as described above, this facsimile device includes an operation panel 6 for operating the device, and the operation panel 6 and a central control section 1.
It also has a telephone 7 for making calls and a telephone controller 71 connected between the telephone 7 and the central control unit 1.

The operation panel 6 is provided with various switches operated by an operator. The switches include a communication start switch, a stop key, and other switches that are required as operating units in general facsimile machines.

Since this facsimile device has a telephone function, a numeric keypad, ie, a dial key, is used for inputting the number of the other party, and this can be provided on the operation panel 6.

FIG. 2 is a block diagram showing the detailed configuration of the reader controller 21. As shown in FIG. That is, between the reader 2 and the system bus, there are provided a character mode binarization circuit 211 that does not perform halftone image processing, a halftone binarization circuit 212 that performs halftone image processing using the dither pattern method, and an error diffusion method. An intermediate:A binarization circuit 213 that performs halftone image processing is connected in parallel, and each of the binarization circuits 211, 2
A command controller 214 operated by a command signal input from the central control unit 1, which will be described later, is connected to 12 and 213.

Only one of the binarization circuits 211, 212, and 213 is activated by a control signal from the command controller 214 to binarize the image data sent from the reader 2.

Next, the transmission control procedure executed by the central control unit 1 will be explained with reference to the flowchart of the transmission control program shown in FIG.

First, in step 301, an operator performs a transmission operation from the operation panel 6.

That is, while inputting the other party's number, G3. Select the G4 communication method, specify the type of original to be sent, etc. For example, the type of document to be sent may be "text only", "text and photos mixed",
"Photos only" etc. To specify the type of document to be sent,
It may also be possible to specify whether or not the transmitted original includes a halftone image. Note that if the above operation is registered in advance in a one-touch dial key or the like, only the one-touch dial key may be operated.

Next, in step 302, the type of the transmitted document is set to "text only".
Determine whether or not. If this answer is negative (No), that is, the type of the transmitted original is "text and photo mixed" or "photo only", etc., and the transmitted original contains a halftone image, then whether the communication method is 64 or not. (Step 303).

If this answer is affirmative (Yes), that is, if the communication method is 64, a command signal for activating the halftone binarization circuit 213 of the error diffusion method is output to the reader controller 21 (step 304), using the G4 communication method. The data is transmitted (step 305) and the program is ended. On the other hand, if the answer to step 303 is negative (NO), that is, the communication method is 03.
If so, a command signal is output to the reader controller 21 to activate the halftone binarization circuit 212 using the dither pattern method (step 306), and transmission is performed using the G3 communication method (step 307), and the program is ended.

Therefore, when transmitting images that require halftone image processing such as photographs, if you use the G3 communication method, which has a slower communication speed than G4, the encoding compression rate will be higher than the error diffusion method. If halftone image processing using the dither pattern method, which has a faster communication speed than the error diffusion method, is selected and is transmitted using the G4 communication method, which has a faster communication speed, the halftone image will be processed using the error diffusion method, which can ensure higher image quality than the dither pattern method. Processing is selected. As a result, excellent communication speed and image quality can be obtained for each communication method.

Returning to step 302, if the answer is affirmative (Yes), that is, the type of the transmitted original is "text only" and the transmitted original does not include a halftone image, the reader controller 2
1, character mode binarization circuit 2 that does not perform halftone image processing
11 (step 3)
08). Next, step 309 similar to step 303
If it is the G4 communication method (affirmative), proceed to step 30 above.
Proceed to step 5, and if it is G3 communication method (no), step 3 above.
Proceed to 07.

In addition, in the above embodiment, the communication methods are G3 and 64,
Although the halftone image processing method has been a dither pattern method and an error diffusion method, the present invention is not limited to these methods, and the present invention provides a facsimile machine that is equipped with multiple types of communication methods and has multiple types of halftone image processing functions. It can be applied to That is, by selecting the optimal halftone image processing function for each communication method, communication speed and image quality can be improved.

(Effects of the Invention) As described in detail above, the present invention provides a facsimile machine that is equipped with multiple types of communication methods and has image processing functions for multiple types of halftones, in which the type of communication method used at the time of transmission is changed. The present invention is characterized by comprising a selection means for selecting one of the plurality of types of halftone image processing functions according to the communication method, so that an appropriate halftone image processing method is selected according to the communication method, and the image quality and Communication speed can be improved.

Further, since the communication method and the halftone image processing method are automatically combined, it is possible to improve the operability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a facsimile device connected to an ISDN according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a detailed configuration of a reader controller 21.
FIG. 3 is a flowchart of the transmission control program executed by the central control unit 1. Simatapu input human error 2 Figure 1...Central control unit, 2...Reader, 21...
212... Intermediate 5!1 binarization circuit of dither pattern method, 213... Halftone binarization circuit of error diffusion method, 214... Command controller,
51...Communication controller.

Claims (1)

[Scope of Claims] 1. In a facsimile machine that is equipped with a plurality of types of communication methods and has a plurality of types of halftone image processing functions, the plurality of types of intermediate tone 1. A facsimile apparatus having a halftone image processing function, characterized in that the facsimile apparatus is provided with a selection means for selecting one of the tone image processing functions. 2. The facsimile device is equipped with G3 and G4 communication methods, and has a halftone image processing function of a dither pattern method and an error diffusion method, and the selection means is configured to allow the facsimile device to communicate using the G3 communication method. 2. A facsimile apparatus having a halftone image processing function as claimed in claim 1, wherein said dither pattern method is selected at times and said error diffusion method is selected when said G4 communication method is used.