JP2002218194A - Facsimile terminal and equipment with built-in facsimile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a facsimile terminal that can avoid a communication error due to time-out while suppressing cost increase and to provide equipment with built-in facsimile. SOLUTION: The coding system is selected on the basis of an evaluation value to evaluate a coding time required for coding so as to avoid a communication error due to time-out without increasing the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoding means for encoding an image using any one of a plurality of encoding methods, and transmitting encoded data of the image encoded by the encoding means. The present invention relates to a facsimile-equipped device, such as a facsimile or a digital multifunction peripheral having a facsimile function, which includes an image transmitting means and a method selecting means for selecting the encoding method used by the encoding means.

[0002]

2. Description of the Related Art In facsimile, MH (Modifi
ed Huffman) coding method, MR (Modified READ) coding method, MMR (Modified MR) coding method, and JBIG
Four (compression) coding schemes, called (Joint Bi-level Coding Experts Group) coding schemes, have been standardized and recommended by the Telecommunication Standardization Sector (ITU-T) of the International Telecommunication Union. Among them, the MMR coding system is recommended for group 4 facsimile, but is also adopted for many group 3 facsimile and is the most frequently used coding system. Further, the JBIG coding method has been recommended relatively recently, and although the facsimile has not been adopted yet, the coding rate is the best. For example, as described in Japanese Patent Application Laid-Open No. 2000-32275, there is a facsimile that employs both the MMR coding method and the JBIG coding method. When a facsimile employing a plurality of encoding schemes transmits an image to another facsimile, generally, the encoding scheme with the highest encoding efficiency among the encoding schemes that can be decoded by the receiving facsimile is facsimile transmission. Selected at that time, and the image is encoded by the selected encoding method. Therefore, both the facsimile on the transmitting side and the facsimile on the receiving side are J
If it is compatible with the BIG coding method, a JBIG coding method having higher coding efficiency than other methods will be selected.

[0003]

SUMMARY OF THE INVENTION J with excellent coding efficiency
If the BIG coding method is selected, the communication time is preferably shorter than when the MMR coding method is selected. However, the encoding time required for encoding an image becomes longer as the encoding rate increases, assuming that the processing capability of the facsimile is the same. When performing the encoding after selecting the encoding method at the time of facsimile transmission, if the encoding time is too long, a communication error due to timeout occurs. In addition, group 3
For facsimile, see V.A. In addition to V.17 modems, V.17 has a higher communication speed. Thirty-four modems have been recommended, and there is a need to shorten the encoding time. If the processing capability of the facsimile is increased, the encoding time can be shortened and the communication error can be avoided, but the cost increases accordingly. The present invention
The facsimile, which has been made in view of such problems in the conventional technology, can prevent a communication error due to a timeout while suppressing an increase in cost.
And a facsimile-mounted device.

[0004]

In order to achieve the above object, the present invention provides an encoding means for encoding an image using any of a plurality of encoding methods, and an encoding means for encoding an image by using the encoding means. A facsimile comprising: an image transmitting unit that transmits the encoded data of the image that has been processed; and a system selecting unit that selects the encoding system used by the encoding unit.
An evaluation value calculating unit for obtaining an evaluation value for evaluating an encoding time required for the encoding unit to encode an image, wherein the method selecting unit determines whether the encoding unit is based on the evaluation value. It is configured as a facsimile characterized by selecting the coding method to be used. The facsimile according to the present invention includes evaluation value calculation means for obtaining an evaluation value for evaluating an encoding time required for encoding an image, and a code for encoding an image to be transmitted based on the evaluation value. Method is selected. For this reason, it is possible to select an encoding method that avoids a communication error due to a timeout, thereby suppressing an increase in cost. In the facsimile, for example, when an image is encoded using a preset encoding scheme among the plurality of encoding schemes, communication with an image receiving apparatus that receives the encoded data is interrupted. Is determined based on the evaluation value, and if it is determined that communication with the image receiving device is not interrupted, the setting encoding method is selected, and communication with the image receiving device is interrupted. If it is determined that the coding method is selected, the coding method having a lower coding rate than the set coding method is selected. When the set encoding method is the encoding method with the highest encoding rate among the plurality of encoding methods, when it is determined that communication with the image receiving apparatus is interrupted, Among them, for example, the coding method having the second highest coding rate is selected. If the coding system with the highest coding rate is the JBIG system, the MMR system is selected when it is determined that the communication with the image receiving device is interrupted. In the facsimile, the evaluation value includes, for example, the encoding when an image is encoded by the encoding unit using an evaluation encoding method predetermined for evaluation among the plurality of encoding methods. The encoding means uses the data size, the number of pixels in which the same value continues in the binary data of the image, and an evaluation encoding system predetermined for evaluation among the plurality of encoding systems. For example, the encoding time for evaluation required when is encoded is used. Furthermore, facsimile-equipped devices such as multifunction devices that combine facsimile functions and printer functions
By providing the facsimile function by mounting the facsimile having the above-described configuration, it is possible to select an encoding method for the facsimile function of the facsimile-equipped device so as to avoid a communication error due to timeout. The increase in cost can be suppressed.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention. FIG. 1 shows a schematic configuration of a facsimile according to an embodiment of the present invention. As shown in FIG. 1, a facsimile A1 according to an embodiment of the present invention includes a reading / recording control unit 1, a network control unit 2, an encoding / decoding control unit 3, an image memory 4, a modem 5, a panel control unit 6, Main control unit 7, control memory 8
And so on. The reading / recording control unit 1 includes, for example, a reading mechanism including a transport mechanism for transporting a document, an optical system for generating electrical image data from an optical image of the document transported by the transport mechanism, and a photoelectric conversion element. And a recording unit that records the supplied image data on a sheet of paper by an ink-jet method or the like, generates the image data, supplies the image data to the encoding / decoding control unit 3, and controls the encoding / decoding control. A circuit for recording the image data supplied from the unit 3 on a sheet. The network control unit 2 is a circuit that controls communication performed via a public telephone line, supplies received data received from the public telephone line to the modem 5, and transmits transmission data supplied from the modem 5 to the modem 5. The data is transmitted to a destination facsimile or the like via a public telephone line. The encoding / decoding control unit 3 performs the reading / recording control by using an evaluation coding method predetermined for evaluation among two coding methods, for example, an MMR coding method and a JBIG coding method. The image data supplied from the unit 1 is encoded, and a read-time encoding process for supplying the encoded data of the image data to the image memory 4 and a demodulated data supplied from the modem 5 are decoded. A decoding process for decoding the encoded data supplied from the image memory 4 and synthesizing the decoded data with other data, and setting the decoded data in advance. This is a circuit that performs encoding using the set encoding method or another encoding method, and performs image synthesis processing to be supplied to the modem 5. In this embodiment, the JBIG coding method is used as both the evaluation coding method and the setting coding method.

The image memory 4 is a memory for storing the encoded data. The modem 5 outputs the transmission data obtained by modulating the encoded data supplied from the encoding / decoding control unit 3 to the network control unit 2 by a modulation method such as polyphase modulation or quadrature amplitude modulation. A modulation / demodulation circuit for demodulating the received data supplied from the network control unit 2 and outputting the demodulated data to the encoding / decoding control unit 3. The panel control unit 6 is a circuit that receives input from a numeric key, a transmission key, and the like, and performs control for displaying an image on a display panel. The main control unit 7 is a circuit that controls the entire facsimile including the above-described configurations 1 to 6. The main control unit 7 has at least the code /
A process of causing the decoding control unit 3 to obtain an evaluation value for evaluating an encoding time required for encoding the image data, and a process of setting a predetermined encoding method among the encoding methods. When the image data is encoded by the encoding / decoding control unit 3, it is determined whether or not communication with the facsimile or the like of the communication destination is interrupted based on the evaluation value. When it is determined that communication with a facsimile or the like is not interrupted, the setting encoding method is selected. When it is determined that communication with the facsimile or the like at the communication destination is interrupted, a code that is higher than the setting encoding method is selected. By selecting the encoding method with a low encoding rate,
And a process for determining the encoding method used by the encoding / decoding control unit 3. The main control unit 7 corresponds to a method selection unit and an evaluation value calculation unit in the present invention. In this embodiment, as the evaluation value, the encoding / decoding control unit 3 encodes the encoded data when the image data is encoded using the evaluation encoding method (JBIG encoding method). Size is used. The control memory 8 is a memory for storing data used by the main control unit 7 and the like.

Hereinafter, a specific operation of the facsimile A1 will be described with reference to flowcharts shown in FIGS. As shown in FIG. 2, first, when it is detected that a document is set by the user, the reading unit records the document according to the control of the reading / recording control unit 1 receiving an instruction from the main control unit 7. Image data is obtained (S101). The image data is supplied from the reading / storing control unit 1 to the encoding / decoding control unit 3, and is determined by the encoding / decoding control unit 3 in advance for the encoding process at the time of reading for evaluation. The image data is encoded by using the evaluation encoding method, here, the JBIG method (S102). The encoded data of the image data encoded by the encoding / decoding control unit 3 is stored in the image memory 4 (S103). Further, according to an instruction from the main control unit 7, the encoding / decoding control unit 3
Then, the size of the encoded data is obtained and stored in the control memory 8 (S104). As soon as the encoded data is stored in the image memory 4 or at a preset date and time, a facsimile transmission process as shown in FIG. 3 is performed under the control of the main control unit 7 (S105). . When the facsimile transmission process is started, for example, the encoded data is read from the image memory 4 to the encoding / decoding control unit 3, and the encoded data is read.
The encoded data is decoded by the decoding control unit 3 (S201). Next, according to the facsimile number of the communication destination input from the panel control unit 6 and stored in the control memory 8, the network control unit 2 receiving the instruction from the main control unit 7 causes the facsimile of the communication destination. A line is connected between the terminal and the like (S202).

When a line is connected to a communication destination facsimile, negotiation is performed with the communication destination facsimile or the like, and the capability of the communication destination facsimile or the like (decoding capability of the decoding method). Is confirmed (S203). According to the result of the confirmation of the capability, the main controller 7 can decode the encoded data encoded by the set encoding method (in this case, the JBIG encoding method) by a facsimile of the communication destination or the like. It is determined whether or not there is (S204). When the main control unit 7 determines that the encoded data encoded by the setting encoding method can be decoded by a facsimile of the communication destination or the like, the encoded data is stored in the control memory 8. The size of the coded data is read, and the main control unit 7 determines whether the size of the coded data is larger than a threshold (S205). The threshold value is determined based on a timeout period determined with the facsimile of the communication destination or the like. If the time period during which no data communication is performed between the facsimile A1 and the facsimile of the communication destination elapses after the timeout period, it is determined that a communication error has occurred and the communication between the facsimile A1 and the facsimile of the communication destination is performed. Is interrupted. If the encoding time required to encode the image data is not shorter than the allowable encoding time obtained by subtracting the time required for other processing such as image synthesis from the timeout time, a communication error due to the timeout time is required. Occurs. FIG. 4 shows the relationship between the encoding time and the size of the encoded data. In FIG. 4, the horizontal axis indicates the encoding (prediction) time, and the vertical axis indicates the size of the encoded data. As shown in FIG. 4, the larger the size of the encoded data is, the shorter the encoding time is.
The smaller the size of the encoded data, the longer the encoding time. For example, when the original is almost blank, the size of the encoded data becomes small, and the encoding time becomes long. Further, when the image data of the original is standard data, the size of the encoded data becomes large, and the encoding time becomes short. When the allowable encoding time _Tc is determined, the relationship between the encoding time and the size of the encoded data as shown in FIG. 4 is read out from the control memory 8 and the main control unit 7 The threshold is determined based on the relationship. In the case of this embodiment, since the coding scheme for evaluation matches the coding scheme for setting, the allowable coding time T _c
And the size of the coded data itself obtained from the relationship is the threshold value for the evaluation value (the size of the coded data when the coding method for evaluation is used).

If the size of the coded data is larger than the threshold value, the coding time when the set coding method is used is within the allowable coding time, and a communication error (communication error due to the timeout time) occurs. If the size of the encoded data is equal to or smaller than the threshold value, the encoding time when the set encoding method is used becomes longer than the allowable encoding time, and the timeout time Causes a communication error. That is, by determining whether or not the size of the coded data is larger than the threshold value, based on the size of the coded data when the evaluation coding system is used, the setting coding system is used. The main control unit 7 determines whether or not communication with the facsimile of the communication destination is interrupted when is used. If the size of the encoded data is larger than the threshold value and it is determined that communication with the communication destination facsimile or the like is not interrupted when the set encoding method is used, the main control unit 7, the encoding method used by the encoding / decoding control unit 3 for the image synthesizing process is determined as the set encoding method (in this case, the JBIG encoding method) (S20).
6). On the other hand, if the size of the encoded data is equal to or smaller than the threshold value and it is determined that communication with the facsimile or the like of the communication destination is interrupted when using the set encoding method, The control unit 7 determines the coding system used by the coding / decoding control unit 3 for the image synthesis process to be a coding system with a lower coding rate than the set coding system, in this case, the MMR coding system ( S20
7). In the step S207, the facsimile of the communication destination or the like can decode the encoded data when the JBIG encoding method is used, but the encoding rate is lower than the JBIG encoding method. It is determined that the MMR coding method is low, but when the size of the coded data is equal to or smaller than the threshold value, in other words, when the document is close to blank, the JBIG coding method is used. The size of the coded data does not change so much whether the method or the MMR coding method is used. For this reason, even if coding is performed using the MMR method instead of the JBIG coding method, there are few disadvantages regarding the transmission time. Further, the frequency at which the size of the encoded data becomes equal to or smaller than the threshold value is less than the frequency at which the size of the encoded data becomes larger than the threshold value. At this time, the JBIG encoding method is used. There is little need to avoid communication errors that occur in the system. On the other hand, if the size of the encoded data is larger than the threshold value, in other words, if the image data of the original is close to the standard data, the J
The difference in the size of the coded data between when the BIG coding method is used and when the MMR coding method is used is large, and the merit of using the JBIG coding method is great. In this case, even when the JBIG coding method is used, the coding time is not so long.
The communication error is less likely to occur.

In step S204, when the main control unit 7 determines that the encoded data encoded by the set encoding method can be decoded by a facsimile or the like of the communication destination. Also, the encoding method used by the encoding / decoding control unit 3 for the image synthesis processing is determined to be another encoding method other than the set encoding method, for example, the MMR encoding method (S20).
7). In the step S206 or the step S207, the encoding method determined by the main control unit 7 is transmitted to the communication destination facsimile or the like via the public telephone line, and is transmitted to the communication destination facsimile or the like. The corresponding decoding scheme is selected. Next,
The decoding control unit 3 performs an image synthesizing process of synthesizing the image data of the header including, for example, the facsimile number and name of the communication destination with the original image data,
The encoding / decoding control unit 3 encodes the synthesized image data using the encoding method determined in S206 or S207 (S208). The coded data of the combined image data coded by the coding / decoding control unit 3 is supplied to the modem 5 and modulated by the modem 5. Then, it is supplied from the model 5 to the network control unit 2 and transmitted to the facsimile of the communication destination through the public telephone line by the network control unit 2 (S209). When the transmission of the transmission data to the communication destination facsimile or the like is completed, a signal indicating completion is transmitted to the communication destination facsimile or the like, and in response, a confirmation message transmitted from the communication destination facsimile or the like is sent. When received, the line to the communication destination facsimile or the like is disconnected (S210), and the facsimile transmission processing is completed. As described above, according to the facsimile according to the embodiment of the present invention, an encoding method that avoids a communication error due to a timeout is selected, so that an increase in cost can be suppressed.

[0011]

In the above embodiment, whether or not communication with the destination facsimile or the like is interrupted is determined based on the size of the encoded data. However, the present invention is not limited to this. For example, communication with a facsimile or the like of the communication destination is performed based on an evaluation encoding time required for encoding when encoding is performed by the encoding / decoding control unit 3 using the encoding method for evaluation. It is also possible to determine whether or not is interrupted. The evaluation coding time is obtained by measuring the time during which the coding / decoding control unit 3 performs the coding using a timer or the like. The obtained coding time for evaluation is stored in the control memory 8 in the same manner as the size of the coded data, and the coded data using the set coding method is decoded by the facsimile of the communication destination or the like. After it is determined by the main control unit 7 that the data can be converted, the data is read from the control memory 8. For example, similarly to the embodiment, both the evaluation coding method and the setting coding method are the JBIG
In the case of the encoding method, whether or not communication with the facsimile of the communication destination is interrupted is determined by the main control unit 7 depending on whether or not the evaluation encoding time is longer than the allowable encoding time. You. When the coding time for evaluation is longer than the permissible coding time, the main control unit 7 determines that communication with a facsimile or the like of the communication destination is interrupted by using the set coding method, The main control unit 7 selects, for example, an MMR coding method having a lower coding rate than the setting coding method as the coding method for the image synthesis processing. On the other hand, when the evaluation encoding time is within the allowable encoding time, the main control unit 7 determines that the communication with the facsimile or the like of the communication destination is not interrupted even by using the set encoding method. The main control unit 7 selects the set coding method as the coding method for the image synthesis processing. In the case where the evaluation coding method is made to match the setting coding method and the determination is made based on the evaluation coding time as described above, or the evaluation coding method is used as in the embodiment. When the determination is made based on the size of the encoded data when used, the encoding time when encoding is performed using the set encoding method is substantially measured in advance. , The communication error can be avoided more reliably. Also, it may be determined whether or not communication with the facsimile or the like at the communication destination is interrupted based on the number of pixels having the same value in the binarized data of the image (hereinafter referred to as the number of continuous pixels). Good. For example, when the number of consecutive pixels in which “0” assigned to white continues among the two values is small, the size of the encoded data becomes small. In this case, the encoding time becomes longer. Conversely, when the number of continuous pixels is large, the size of the encoded data increases, and the encoding time decreases. Therefore, for example, if the number of continuous pixels is 1000
By comparing the count value obtained by counting the number of blocks with a threshold value obtained based on the permissible encoding time, it is determined whether or not communication with the facsimile of the communication destination is interrupted. Is performed by the main control unit 7. If the count value is equal to or less than the threshold value, the main control unit 7 determines that communication with the facsimile of the communication destination is not interrupted, and the main control unit 7
Selects the setting encoding method as the encoding method for the image synthesis processing. On the other hand, if the count value is larger than the threshold value, the main control unit 7 determines that the communication with the facsimile or the like of the communication destination is interrupted, and the main control unit 7 controls the image synthesis processing. The setting encoding method is selected as the encoding method. In the above-described embodiment, the present invention is applied to a facsimile-dedicated machine. However, the present invention is not limited to this. It is possible to apply the invention.

[0012]

As described above, in the facsimile and the facsimile-equipped device according to the present invention, it is possible to select an encoding method for avoiding a communication error due to a timeout, thereby suppressing an increase in cost.

[Brief description of the drawings]

FIG. 1 shows a facsimile A1 according to an embodiment of the present invention.
The figure which shows the schematic structure of.

FIG. 2 is a flowchart for explaining a schematic operation of the facsimile A1.

FIG. 3 is a flowchart for more specifically explaining the operation at the time of transmission of the facsimile A1.

FIG. 4 is a diagram showing the relationship between the size of encoded data and the time required for encoding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reading / recording control part 2 ... Network control part 3 ... Encoding / decoding control part 4 ... Image memory 5 ... Modem 6 ... Panel control part 7 ... Main control part 8 ... Control memory

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Katsumi Nagata 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Tamotsu Shuto 22-22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Shigeki Nakahara 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (72) Inventor Tsutomu Taniguchi 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F term in reference (reference) 5C075 CA01 CE90 FF90 5C078 AA01 AA04 BA27 BA32 CA02 DA00 DA01 DA02

Claims (7)

[Claims] An encoding unit that encodes an image using any one of a plurality of encoding systems; an image transmission unit that transmits encoded data of the image encoded by the encoding unit; An evaluation value calculation for obtaining an evaluation value for evaluating an encoding time required for the encoding means to encode an image in a facsimile having a method selecting means for selecting the encoding method used by the encoding means; Facsimile, wherein the method selecting means selects the coding method used by the coding means based on the evaluation value. 2. The method according to claim 1, wherein said method selecting means is configured to, when an image is encoded by said encoding means using a preset setting encoding method among said plurality of encoding methods, encode said encoded data. It is determined based on the evaluation value whether or not communication with the image receiving device that receives the communication is interrupted. If it is determined that communication with the image receiving device is not interrupted, the setting encoding method is selected. 2. The facsimile apparatus according to claim 1, wherein when it is determined that communication with the image receiving apparatus is interrupted, the coding method having a lower coding rate than the set coding method is selected. 3. The facsimile according to claim 2, wherein the set coding method is a coding method having the highest coding rate among the plurality of coding methods. 4. The encoded data when the image is encoded by the encoding means using an evaluation encoding system predetermined for evaluation among the plurality of encoding systems. The facsimile according to any one of claims 1 to 3, which has a size of: 5. The facsimile according to claim 1, wherein the evaluation value is the number of pixels having the same value in the binarized data of the image. 6. An evaluation value required when an image is encoded by said encoding means using an evaluation encoding method predetermined for evaluation among said plurality of encoding methods. The facsimile according to any one of claims 1 to 3, which is an encoding time. 7. A facsimile mounting device comprising the facsimile according to claim 1.