JPH07226847A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To conduct the optimum encoding of a picture and to hold high quality. CONSTITUTION:When an operation mode inputted from a key input part 1 is checked and it is a regular communication mode, a picture original is inputted and a JPEG compression/expansion circuit 15a following a JPEG system compresses the original, and the picture data are transmitted to a communication opposite party. When the input operation mode is an editing possible mode and a display possible mode, picture data are compressed by a JBIG compression/expansion circuit 15b, and the picture data are transmitted to the communication opposite party.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine.

[0002]

2. Description of the Related Art A conventional color facsimile apparatus has only a compression / decompression circuit that complies with one encoding / decoding method in all operations related to color image processing. In particular, the encoding method is often JPEG.

[0003]

However, in the above-mentioned conventional example, since the same encoding method is used in all operations, the encoding method must be appropriate for the image.
There are drawbacks that it takes time to display an image on the screen and the image quality is deteriorated.

In addition, DC, which is common in JPEG encoding,
The T method is an irreversible encoding method in which a DCT calculation error and loss of information due to quantization occur, so that a compressed image cannot be completely restored to the original image, and processing can be performed many times. There is a drawback that the image quality deteriorates when repeated.

The present invention has been made in view of the above conventional example, and an object of the present invention is to provide a facsimile apparatus capable of maintaining a high quality image by appropriately encoding an image.

[0006]

To achieve the above object, a color image facsimile apparatus of the present invention has the following configuration. That is, a facsimile apparatus operating in a plurality of operation modes, an input unit for inputting an image original,
Input instruction means for inputting a desired operation mode from the plurality of operation modes, a plurality of compression / decompression means according to different encoding methods, and image data of an image original input from the input means is transmitted to a communication line. According to the operation mode instructed by the transmitting means, the receiving means for receiving the image data from the communication line, the optimum compressing / expanding means is selected from the plurality of compressing / expanding means to compress / compress the image.
And a control unit for controlling the expansion so that the facsimile apparatus is provided.

[0007]

With the above-described structure, the present invention operates so as to encode an image by the encoding method suitable for the operation mode by providing a plurality of compression / expansion means according to the encoding method different from the operation modes.

Further, according to the additional information of the image data of the image original input from the input means and the image data received from the receiving means, it is determined whether or not further image compression / expansion is performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a block diagram showing the schematic arrangement of a color facsimile apparatus which is a typical embodiment of the present invention. The operation of this device is performed by inputting various information from the key input unit 1 by an operator, and the display unit 2
Various messages and images are displayed on the screen. The key input unit 1 and the display unit 2 are provided on the same operation panel (not shown), and are connected to the system bus 16 via the panel control unit 3.

Further, in FIG. 1, reference numeral 4 denotes a DMA controller (hereinafter referred to as DMAC) for performing DMA transfer of image data and the like.
5 is an image information output unit including a color printer, 6 is an image information input unit including a scanner for reading an image original, 7 is an image information output unit 5, image information input unit 6 and a system bus. Interface control with the image information output unit 5 and the image information input unit 6
The image input / output control unit 7 for controlling the. Reference numerals 8 and 9 denote communication units, which perform communication via the communication lines 21 and 22. Reference numeral 10 denotes a communication control unit that controls the communication units 8 and 9, and 11 stores compressed image data received via the communication units 8 and 9 or compressed image data that is input from the image information input unit 6 and becomes an image for transmission. It is an auxiliary storage unit having a large-capacity storage device such as a hard disk.

Further, 12 is an MPU for outputting various data signals and control signals to control the entire apparatus, and 13-1 is an MPU.
A ROM 13-2 that stores a control program executed by the U12, which will be described later, is used as a work area of the MPU 12, and RA that temporarily stores various control data.
M and 14 are images for temporarily storing the image data input from the image information input unit 6 or received from the communication units 8 and 9, and storing the image data output to the image information output unit 5 and the like. A memory, 15 is a compression / decompression unit capable of compressing / decompressing image information transmitted / received via the communication units 8 and 9 using a plurality of encoding methods, and 17 is various auxiliary information. It is a floppy disk to store.

The compression / expansion section 15 of this embodiment has a JP
JPEG compression / decompression circuit 15a and JBIG conforming to the EG method
The JBIG compression / expansion circuit 15b according to the system is provided in two systems, and either one is selected and used according to the operation mode input from the key input unit 1. Further, the operation mode of the apparatus of the present embodiment can be edited to edit the input image data in addition to the normal communication mode in which the image data input to the apparatus is directly transmitted to the facsimile device of the communication partner, and the transmission processing of the input image data. It is assumed that there are three modes: a mode and a displayable mode in which the input image data is displayed on the display unit 2 in addition to the input image data transmission process.

Next, the transmission processing executed by the color facsimile apparatus having the above-mentioned structure will be described with reference to the flowchart shown in FIG. In addition, the explanation below is mainly about MPU.
Although the operation is controlled by 12, the operation of each unit is also included.

First, in step S1, the input from the key input unit 1 is awaited. Here, if there is a key input for instructing the start of the transmission operation, the process proceeds to step S2 and waits for the input of the operation mode. Here, if the operation mode is input, the process proceeds to step S3.

In step S3, it is checked whether the input operation mode is normal communication. If it is determined that the mode is the normal communication, the process proceeds to step S4 and the image input / output control unit 7
The document is read from the image information input unit 6 and the image memory 14 is read.
Accumulate in. Further, in step S5, the image memory 14
The information inside is transferred to the compression / expansion unit 15, JPEG compression is performed using the JPEG compression / expansion circuit 15a, and the compressed information is transferred to the image memory 14 again. Further on,
In step S6, the compressed information stored in the image memory 14 is transferred to the communication unit 8 via the communication control unit 10 and the compressed information is communicated to the facsimile device of the communication partner, and the process ends.

On the other hand, if it is determined in step S3 that the operation mode is not normal communication, the process proceeds to step S7, and it is further checked whether the operation mode is the editable mode. Here, when it is determined that the operation mode is the editable mode, the process proceeds to step S8, the original is read from the image information input unit 6 via the image input / output control unit 7, and is stored in the image memory 14. accumulate. Further, in step S9, the information in the image memory 14 is transferred to the compression / expansion unit 15, JBIG compression is performed using the JBIG compression / expansion circuit 15b, and the compressed information is transferred again to the image memory 14. Further, the process proceeds to step S6, and as described above, the compressed information in the image memory 14 is transmitted to the facsimile device of the communication partner.

If it is determined in step S7 that the operation mode is not the editable mode, the process proceeds to step S10 to check whether the operation mode is the displayable mode. Here, when it is determined that the mode is the displayable mode, the process proceeds to step S11, the original is read from the image information input unit 6 via the image input / output control unit 7, and the image memory 14 is read. accumulate. Then, the process proceeds to step S9 to compress the information in the image memory 14 according to the JBIG method as described above. Thereafter, the process proceeds to step S6 as described above.

On the other hand, if it is determined in step S10 that the operation mode is not the displayable mode, it is regarded as an operation mode input error and the process returns to step S1 to wait for the next input from the key input unit 1. Becomes

Therefore, according to the present embodiment, it is possible to switch the encoding method according to the input operation mode and perform the optimum image compression for the operation mode. For example, since JPEG encoding is performed for normal communication, there is an advantage that a high image compression rate can be obtained and communication time is shortened. On the other hand, in editable mode, JBIG encoding is performed, so that high communication is possible. There is an advantage that the image quality can be maintained.

In this embodiment, only the JPEG method and the JBIG method are used as the encoding method used for compression / expansion, but it goes without saying that other encoding methods can be used. Regarding the operation mode, only three operation modes were used in the present embodiment, but other elements, for example, data contents such as characters / photographs, images input from a scanner or a computer-generated image It goes without saying that it is possible to adopt an operation mode in which the encoding method can be changed depending on the information.

[Second Embodiment] In this embodiment, a color facsimile apparatus having the same configuration as that of the first embodiment is used to perform compression / compression.
Information on the history of image processing such as decompression and resolution conversion,
An example in which the deterioration of the image is prevented by holding it in the color image file will be described. Since the configuration of the device in this embodiment is the same as that of the device in the first embodiment,
The description of the device configuration and operation will be omitted.

Next, the facsimile communication (transmission and reception) processing according to this embodiment will be described with reference to the flowcharts shown in FIGS. Note that FIG. 3 shows the transmission process, and FIG. 4 shows the reception process.

(1) Transmission Process First, in step S12, a key input from the key input unit 1 is awaited. Here, if there is a key input, the process proceeds to step S13, the image information is input from the image information input unit 6 via the image input / output control unit 7, and is stored in the image memory 14. Next, in step S14, the image information in the image memory 14 is transferred to the compression / expansion unit 15, JPEG compression is performed using the JPEG compression / expansion circuit 15a, and the compressed image information is transferred to the image memory 14. Next, step S
At 15, the image information and the image processing history are transferred to the auxiliary storage unit 11 to create a color image file (hereinafter referred to as a file).

Next, in step S16, the communication unit 8 sends a call to the facsimile machine of the communication partner via the communication control unit 10. In step S17, when the line connection is confirmed, the attribute of the facsimile device of the communication partner is received and the negotiation is performed. Then, step S18
At, it is checked whether or not conversion of image information, for example, conversion of resolution or paper size is required according to the attribute of the facsimile device of the communication partner. If it is determined that such conversion is necessary, the process proceeds to step S19, the image information is transferred from the auxiliary storage unit 11 to the compression / decompression unit 15, and the image conversion is performed. Then, in step S20, the converted image information is again written in the auxiliary storage unit 11 in the file together with the image conversion history. On the other hand, if it is determined that the image information conversion is not necessary, the process proceeds to step S21.

Finally, in step S21, this file is transmitted from the communication section 8 to the communication partner via the communication control section 10, and the processing is terminated.

(2) Reception Processing First, in step S22, when the communication section 8 detects an incoming call from the facsimile apparatus of the communication partner, the communication control section 10
The document is received via the, and the received document is stored in the auxiliary storage unit 10 as a file. At the same time, the file holds a history of received images such as the received resolution. Next, in step S23, it is checked whether or not the received document is immediately output as it is. Here, in the case of immediate output, the process proceeds to step S24, the received files accumulated in the auxiliary storage unit 10 are transferred to the image memory 14, and further transferred to the compression / expansion unit 15 for expansion processing. , And transfers the expanded image to the image memory 14. Then, this image is output from the image information output unit 5 via the image input / output control unit 7, and the process ends. On the other hand, if immediate output is not to be performed, the process proceeds to step S25.

In step S25, the process checks whether or not the received document image is further transmitted. This is the case, for example, when the receiving device performs the image relay function. Here, in the case of transmitting, the process proceeds to step S26, while in the case of not transmitting, the process proceeds to step S35.

In step S26, for example, a call is made from the communication section 8 via the communication control section 10 to a facsimile apparatus as a relay destination, and after confirming the line connection in step S27, the attribute of the communication partner apparatus is received to negotiate. I do. In step S28, the negotiation result is examined to determine whether image conversion is necessary. If it is determined that the image conversion is necessary, the process proceeds to step S
In 29, if the image conversion is not necessary, the process proceeds to step S32.

In step S29, the conversion history stored in the received file is read from the auxiliary storage unit 10 and it is checked whether the image quality is deteriorated by further conversion. For example, if compression / expansion is performed many times by the encoding method according to JPEG, image quality deteriorates. Therefore, it is checked based on the conversion history whether compression / expansion is performed a predetermined number of times or more. If it is determined that the conversion is still possible, the process proceeds to step S30, the image information is read from the auxiliary storage unit 10, transferred to the image memory 14, and further transferred to the compression / decompression unit 15 to convert the image. I do. Then, the converted image is transferred to the image memory 14 again. Further, in step S31, the image information of the image memory 14 is written in the file of the auxiliary storage unit 10 together with the processing history. Then, the process proceeds to step S32.

On the other hand, if it is determined in step S29 that the image quality is deteriorated by further image conversion,
The process proceeds to step S33, an error message is displayed on the display unit 2 via the panel control unit 3, and the step S34
In step 1, the communication control unit 10 is instructed to interrupt the communication, and the process ends.

In step S32, the communication unit 8 transmits the image (the image that has been subjected to the image conversion or the image that has not been subjected to the conversion process) from the communication unit 8 via the communication control unit 10, and the process is terminated.

When it is determined in step S25 that the image is not transmitted, the process stores the received image information in the auxiliary storage unit 11 in step S35, and the process ends. An example of this is confidential reception, in which a document is output according to an operator's instruction.

Therefore, according to the present embodiment, since image processing such as compression / expansion and resolution conversion is performed according to the history information, it is possible to prevent deterioration of image quality associated with image conversion such as compression / expansion many times.

In the present embodiment, the present invention that checks whether image conversion is possible only when transmitting after reception is not limited to this. For example, in other cases, it can be applied to display and editing. Further, in the present embodiment, when the received image has to be transmitted after the reception and the image conversion is necessary, but the conversion is impossible, the process of interrupting the communication is performed. However, the present invention is not limited to this. For example, instead of interrupting communication, another encoding method may be adopted to perform image conversion that does not deteriorate image quality and continue the processing.

Although the JPEG system and the JBIG system have been considered as the image encoding system in the above two embodiments, the present invention is not limited to this, and it goes without saying that other encoding systems can be adopted.

Further, in the above-mentioned two embodiments, the color facsimile machine having a large amount of image data and having a remarkable effect of image compression has been described as an example, but the present invention is not limited to this and is applied to a normal monochrome facsimile machine. It goes without saying that you can do it.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0039]

As described above, according to the present invention, a plurality of compression / compression according to a plurality of operation modes and an encoding method different from that of the plurality of operation modes are performed.
Since the image is encoded by the encoding method suitable for the operation mode by providing the decompression means, there is an effect that high quality image quality can be maintained.

Further, since it is determined whether or not further compression / decompression is performed according to the additional information of the image data, there is an effect of preventing deterioration of image quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a color facsimile apparatus that is a typical embodiment of the present invention.

FIG. 2 is a flowchart showing a coding method selection and transmission process according to an input operation mode according to the first embodiment.

FIG. 3 is a flowchart showing a facsimile transmission process according to the second embodiment.

FIG. 4 is a flowchart showing a facsimile reception process according to the second embodiment.

[Explanation of symbols]

 1 Key Input Section 2 Display Section 3 Panel Control Section 4 DMAC 5 Image Information Output Section 6 Image Information Input Section 7 Image Input / Output Control Section 8, 9 Communication Section 10 Communication Control Section 11 Auxiliary Storage Section 12 MPU 13-1 ROM 13- 2 RAM 14 image memory 15 compression / expansion unit 15a JPEG compression / expansion circuit 15b JBIG compression / expansion circuit 16 system bus 17 floppy disk device

Claims (6)

[Claims] 1. A facsimile apparatus operating in a plurality of operation modes, wherein input means for inputting an image original, input instruction means for inputting a desired operation mode from the plurality of operation modes, and different encoding methods A plurality of compression / decompression means, a transmission means for transmitting the image data of the image original input from the input means to a communication line, a reception means for receiving the image data from the communication line, and the operation instructed to input. A facsimile apparatus comprising: control means for controlling an optimum compression / expansion means by selecting an optimum compression / expansion means from the plurality of compression / expansion means in accordance with a mode. 2. A storage unit for storing the image data of the image original input from the input unit and the additional information of the image data received from the receiving unit together with the image data, and a further image according to the additional information. 2. The facsimile apparatus according to claim 1, further comprising: a determination unit that determines whether or not to perform compression / decompression of. 3. The facsimile apparatus according to claim 2, wherein the additional information includes a resolution of the image data and a history of compression / expansion. 4. The facsimile apparatus according to claim 1, wherein the plurality of compression / expansion means include compression / expansion means according to the JPEG system and compression / expansion means according to the JBIG system. 5. An image processing unit for further editing the image data of the image original input from the input unit or the image data received from the receiving unit, and a display unit for displaying the image data. The facsimile apparatus according to claim 1, which is characterized in that. 6. The first operation mode in which the plurality of operation modes is instructed to be transmitted by the transmission unit without performing any editing process on the image data of the image original input from the input unit, and the input unit. A second mode in which image data of the image document input from the image processing unit is edited by the image processing unit and transmission by the transmission unit is instructed; and image data of the image document input from the input unit is displayed by the display unit. 6. The facsimile apparatus according to claim 5, further comprising a third mode for instructing a display by and a transmission by the transmitting means.