Image communication apparatus, method and a non-transitory computer-readable storage medium to generate both image data beforehand for low and high speed facsimile transmission

An image communication apparatus enabling reduction of line occupation time and communication charge. The image communication apparatus generates image data for high-speed transmission and image data for low-speed transmission from input image data. Before transmission of image data, it is determined whether high-speed transmission of the image data is possible. When the high-speed transmission of the image data is determined to be possible, the image communication apparatus selects the image data for high-speed transmission, whereas when the same is determined to be impossible, the image communication apparatus selects the image data for low-speed transmission.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image communication apparatus, a method of controlling the same, and a storage medium, and more particularly to a control technique for use in transmitting image data to a transmission destination by facsimile transmission according to SIP (session initiation protocol).

2. Description of the Related Art

Besides a conventional facsimile transmission technique using a public switched telephone network (PSTN), there have been proposed a facsimile transmission technique using a LAN (local area network), which enables high-speed transmission and is configured to be compatible with the facsimile transmission technique using the public switched telephone network. For example, according to ITU-T Recommendation T.38, point-to-point transmission is achieved on a LAN and hence a LAN is used as a transmission path and SIP (session initiation protocol) is used as a call control unit. For example, there has been proposed a network called the NGN (next generation network), for achieving telephone service, video communication service, and the like, using SIP. On the NGN, it is possible to provide band guarantee, phone number authentication, and so forth, to thereby perform high-speed and secure image transmission.

PSTN transmission speed is 33.6 kbps maximum, whereas the NGN guarantees a transmission speed of 1 Mbps maximum. Therefore, the NGN can realize approximately 30 times faster transmission speed. For example, the use of the NGN enables transmission of a high-definition and high-resolution image or color image, which has not been welcomed because of a long transmission time and a high communication charge, to be performed in a short time and for a small communication charge.

Further, ITU-T Recommendation T.38 is compatible with ITU-T Recommendation T.30 used on the PSTN. For this reason, transmission is possible between an image communication apparatus to which is applied ITU-T Recommendation T.38 (hereinafter referred to as “the T.38-based apparatus”) and an image communication apparatus to which is applied ITU-T Recommendation T.30 (hereinafter referred to as “the T.30-based apparatus”). This transmission can be achieved by providing a T.38 gateway (GW) for interconversion between T.38 and T.30, between a LAN line, such as the NGN and the conventional PSTN.

However, the capabilities of the T.30-based apparatus are reflected on the transmission speed and hence the transmission speed cannot exceed 33.6 kbps. Transmission on a LAN between T.38-based apparatuses can be performed at a high speed for a small charge, but transmission from the T.38-based apparatus to the T.30-based apparatus cannot be performed at a transmission speed higher than 33.6 kbps, so that transmission has to be performed at a low speed for a high charge as in the prior art. Further, due to transmission performed at a low speed, the communication line is occupied, which makes it impossible to perform other transmission until the occupied state of the communication line is over.

To solve this problem, there has been proposed e.g. a technique of changing control based on whether or not transmission is to be performed between T.38-based apparatuses (see e.g. Japanese Patent Laid-Open Publication No. 2002-111952). According to this publication, in a case where facsimile transmission is performed from a T.38-based apparatus, the T.38-based apparatus detects whether a transmission destination apparatus is a T.38-based apparatus directly connected to a LAN or a T.30-based apparatus connected to the LAN via a gateway. Then, according to a result of the detection, a signal wait time period specified in T.30 or T.38 associated with a detected type of the transmission destination apparatus is selected (when the transmission destination apparatus is a gateway connected type, a longer wait time period is selected so as to compensate for a time lag that occurs when the transmission is performed via the gateway). Note that Japanese Patent Laid-Open Publication No. 2002-111952 relates only to the technique of compensating for a lag time that occurs when a gateway is interposed, to thereby stabilize communication, but it makes no mention of image control (i.e. control of image quality and a color image) to which the present invention is directed.

In a case where a high-resolution image or a color image is transmitted from the T.38-based apparatus, when a transmission destination apparatus is directly connected to a high-speed communication line (LAN or NGN), it is possible to achieve high-speed transmission for a small charge. However, when a transmission destination apparatus is a T.30-based apparatus that is not directly connected to a LAN (NGN), transmission is performed at the same transmission speed as the conventional PSTN transmission speed, i.e. at a low speed. As a consequence, the communication line is occupied for a long time period and a high communication charge has to be paid.

SUMMARY CF THE INVENTION

The present invention provides an image communication apparatus which makes it possible to shorten a line occupation time as well as to reduce communication charge, a method of controlling the image communication apparatus, and a storage medium.

In a first aspect of the present invention, there is provided an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), comprising a generation unit configured to generate image data for high-speed transmission and image data for low-speed transmission, from input image data, a determination unit configured to determine, before transmission of image data by the transmission unit, whether or not high-speed transmission of the image data is possible, and a selection unit configured to select the image data for high-speed transmission when the determination unit determines that high-speed transmission of the image data is possible, and select the image data for low-speed transmission when the determination unit determines that high-speed transmission of the image data is impossible, wherein the transmission unit transmits image data selected by the selection unit.

In a second aspect of the present invention, there is provided an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), comprising a voice communication determination unit configured to determine whether or not transmission of the image data is to be performed by voice communication, wherein when the voice communication determination unit determines that transmission of the image data is to be performed by voice communication, the transmission unit generates smaller-amount image data than the image data from the image data and transmits the generated image data.

In a third aspect of the present invention, there is provided a method of controlling an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), comprising generating image data for high-speed transmission and image data for low-speed transmission from input image data, determining, before transmission of image data by the transmission unit, whether or not high-speed transmission of the image data is possible, selecting the image data for high-speed transmission when it is determined that high-speed transmission of the image data is possible, and selecting the image data for low-speed transmission when it is determined that high-speed transmission of the image data is impossible, and transmitting the selected image data.

In a fourth aspect of the present invention, there is provided a method of controlling an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), comprising determining whether or not transmission of the image data is to be performed by voice communication, and generating, when it is determined that transmission of the image data is to be performed by voice communication, smaller-amount image data than the image data from the image data, and transmitting the generated image data.

In a fifth aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program for causing a computer to execute a method of controlling an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), wherein the method comprises generating image data for high-speed transmission and image data for low-speed transmission from input image data, determining, before transmission of image data by the transmission unit, whether or not high-speed transmission of the image data is possible, selecting the image data for high-speed transmission when it is determined that high-speed transmission of the image data is possible, and selecting the image data for low-speed transmission when it is determined that high-speed transmission of the image data is impossible, and transmitting the selected image data.

In a sixth aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program for causing a computer to execute a method of controlling an image communication apparatus including a transmission unit that is connected to a network and performs facsimile transmission of image data to a transmission destination according to session initiation protocol (SIP), wherein the method comprises determining whether or not transmission of the image data is to be performed by voice communication, and generating, when it is determined that transmission of the image data is to be performed by voice communication, smaller-amount image data than the image data from the image data, and transmitting the generated image data.

According to the present invention, determination as to the capabilities of a transmission destination apparatus and a transmission path is performed, and when it is determined that transmission is to be performed at a low speed, an image to be transmitted is converted to low-resolution data or monochrome data suitable for low-speed transmission and is then transmitted. This makes it possible to shorten a line occupation time as well as to reduce communication charge.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a diagram of a network including an image communication apparatus according to a first embodiment of the present invention.

Referring toFIG. 1, the image communication apparatus100is a T.38-based apparatus. An NGN101is a LAN line, such as a next generation network (NGN). A home gateway (hereinafter abbreviated as “the HGW”)102is connected to the image communication apparatus100and the NGN101, and is used for interconnection therebetween.

An image communication apparatus103is one transmission destination apparatus as a communication partner of the image communication apparatus100. Similarly to the image communication apparatus100, the image communication apparatus103is a T.38-based apparatus. Communication between the image communication apparatuses100and103is performed via the HGW102and the NGN101.

In communication between the image communication apparatuses100and103, point-to-point communication is performed using SIP (session initiation protocol) for a call control process prior to facsimile transmission using ITU-T Recommendation T.38. For communication between the image communication apparatuses100and103, only a high-speed line, such as an NGN, is used, so that it is possible to perform communication at a speed of 1 Mbps maximum to thereby achieve high-speed and low-charge communication.

An image communication apparatus106is another transmission destination apparatus as another communication partner of the image communication apparatus100. The image communication apparatus106is a T.30-based apparatus. The communication between the image communication apparatuses100and106is performed as follows: The image communication apparatus100is connected to the NGN101via the HGW102. Between the NGN line and a general PSTN (public switched telephone network)105is connected a T.38 gateway (GW)104. The T.38 gateway104performs interconversion between a signal based on specifications of T.38 and a signal based on specifications of T.30 as a facsimile communication standard for the PSTN. The T.38 gateway104is connected to the image communication apparatus106via the PSTN105.

In the example shown inFIG. 1, high-speed data transmission is possible from the image communication apparatus100to the T.38 gateway104, but since the conventional analog line is used for data transmission from the T.38 gateway104to the image communication apparatus106, the transmission speed cannot exceed 33.6 kbps. Consequently, high-speed transmission is impossible.

Next, a description will be given of a communication method using VoIP (voice over IP) on the network shown inFIG. 1. VoIP is a technique for causing voice packets to be transmitted over a LAN, such as an IP network.

InFIG. 1, a VoIP gateway107is used for interconversion between a voice packet on the LAN (NGN101) side and a voice signal on the PSTN (PSTN105) side. A VoIP communication on theFIG. 1network is established between any two of the image communication apparatus100, the HGW102, the NGN101, the VoIP gateway107, the PSTN105, and the image communication apparatus106. In the VoIP communication, a voice signal is transmitted without being processed and therefore transmission is performed at a low speed of 33.6 kbps.

As described above, when a communication partner is a T.38-based apparatus that uses a high-speed line, communication can be performed at a high speed (1 Mbps maximum), whereas when a T.38 gateway or a VoIP gateway is used, communication has to be performed at a low speed (33.6 Kbps maximum). Further, in communication between T.38-based apparatuses, since high-speed transmission can be performed, it is possible to transmit a color image or a hyper-resolution (e.g. 1200 bps×1200 bps) image by facsimile transmission at a high speed for a small charge.

FIG. 2is a schematic block diagram of the image communication apparatus100appearing inFIG. 1.

InFIG. 2, a CPU201controls various devices appearing inFIG. 2, based on control programs stored in a ROM208. A display and operation section203displays e.g. windows, icons, messages, menus, and other user interface information, on a display screen thereof. The display and operation section203comprises various kinds of keys, not shown, via which a user performs operations for copying, facsimile transmission, and printing, and a screen pointing device, not shown, with which the user operates an icon, a menu, etc. displayed on the display screen.

A scanner section204is provided with a function for reading an image from an original. A printer section205prints print data stored in a RAM209or a HDD (hard disk drive)210. The ROM208stores various kinds of control programs and data. The RAM209is used as a work area in which the CPU201temporarily stores data, a data save area for use in error processing, a load area for control programs, and so forth.

The HDD210is an external storage device for storing various kinds of control programs and print data. A network interface (I/F) section213controls connection of the image communication apparatus100to the HGW102and the network. Communication using SIP is also performed via the network interface section213.

A T.38 protocol generation/analysis section214has a function for generating facsimile transmission information to be transmitted according to a protocol of ITU-T Recommendation T.38, and a function for analyzing received facsimile transmission information.

An IP packet generation/analysis section206has a function for mapping the protocol of ITU-T Recommendation T.38 to IP packets, and a function for extracting the protocol of ITU-T Recommendation T.38 from received IP packets. An image conversion controller207performs compression, expansion, zooming, and linear density conversion of images to be transmitted and received by facsimile communication.

Note that the image communication apparatus103has the same configuration as the image communication apparatus100, and hence description thereof is omitted. Further, the image communication apparatus106is different from the image communication apparatus100only in that a protocol of ITU-T Recommendation T.30 is used in place of ITU-T Recommendation T.38 protocol, and hence description of the configuration thereof is also omitted.

Next, a description will be given of a facsimile transmission process performed by the image communication apparatus100.

FIG. 3is a flowchart of the facsimile transmission process executed by the image communication apparatus100.

First, the CPU201determines in a step S301whether or not a facsimile transmission instruction has been received from the user via the display and operation section203. If it is determined that the facsimile transmission instruction has been received, the CPU201proceeds to a step S302, wherein the CPU201determines whether or not in the received facsimile transmission instruction, facsimile transmission of a color image or a hyper-resolution image of more than 600 dpi has been designated. If it is determined that facsimile transmission of a color image or a hyper-resolution image of more than 600 dpi has not been designated, the CPU201proceeds to a step S305. On the other hand, if it is determined that facsimile transmission of a color image or a hyper-resolution image of more than 600 dpi has been designated, the CPU201proceeds to a step S303.

In the step S305, the CPU201causes the scanner section204to perform normal reading of an image from an original. Then, the CPU201performs connection call by a SIP connection process to thereby initiate a call and connect to a transmission destination (step S306), and then transmits data (step S313). When the data transmission is completed (YES to a step S314), the CPU201causes the network interface section213to perform line disconnection (step S315). Normal facsimile transmission using ITU-T Recommendation T.38 is performed through the above-described processing.

In the step S303, the CPU201determines a transmission mode to be used. The transmission mode in the present embodiment comprises a T.38 transmission mode in which transmission is performed by a procedure defined in T.38 and a VoIP transmission mode in which transmission is performed by voice communication using VoIP. Selection of a transmission mode between the T.38 transmission mode and the VoIP transmission mode is performed in advance by a user or is automatically performed by judgment based on a telephone number to which a call is initiated. The case of selection of a transmission mode by the user is a case of selection of a communication mode, which is executed e.g. by selecting between a communication mode defined in T.38 in advance and a communication mode based on voice. On the other hand, in the case of automatically determining a transmission mode based on a telephone number, it is determined whether or not the telephone number has an area code (e.g. 03, 06, or the like in Japan) generally used on the PSTN, and if the telephone number is determined to be a PSTN number, it is automatically determined that the communication mode is the communication mode based on voice, based on which the VoIP transmission mode is selected.

If it is determined in the step S303that the transmission mode to be used is not the VoIP transmission mode, the CPU201proceeds to a step S307. On the other hand, if it is determined that the transmission mode to be used is the VoIP transmission mode, high-speed transmission is not possible, and therefore the CPU201instructs the scanner section204to perform image reading in monochrome or in low resolution (step S304), and then, the step305et seq. are executed. Thus, in VoIP transmission, even when facsimile transmission of a color image or a hyper-resolution image is designated before execution of facsimile transmission, reading of a monochrome image or a low-resolution image is performed. That is, when it is determined that transmission is to be performed at a low speed, an image to be transmitted is converted to a monochrome or low-resolution image suitable for low-speed transmission and is then transmitted. This makes it possible to shorten a line occupation time as well as to reduce communication charge.

If facsimile transmission of a color image or a hyper-resolution image is designated and when the transmission mode to be used is not the VoIP transmission mode, the step S307et seq. steps are executed. In this case, in the illustrated example, a possible communication partner of the image communication apparatus100is the T.38-based apparatus (image communication apparatus103) to which the image communication apparatus100is connected via the HGW102and the NGN101or the T.30-based apparatus (image communication apparatus106) to which the image communication apparatus100is connected via the HGW102and the NGN101and further via the T.38 gateway104and the PSTN105.

In the step S307, the following processing is executed. The CPU201cannot determine whether or not high-speed transmission to a transmission destination is possible, until a call connection is made. Therefore, the CPU201causes the T.38 protocol generation/analysis section214to generate two kinds of image data, i.e. image data for high-speed transmission and image data for low-speed transmission, based on input image data. This is because if image conversion is performed after establishment of connection to a transmission destination apparatus, it takes time to complete the image conversion and hence it is impossible to guarantee real-time transmission. For example, when color image transmission has been designated, the CPU201causes the scanner section204to generate not only a color image but also a monochrome image from an original. Similarly, when hyper-resolution image transmission has been designated, the CPU201causes the scanner section204to generate not only an image of hyper resolution (e.g. 1200×1200 dpi) but also an image of a low resolution (e.g. 400×400 dpi) from an original.

Then, in a step S308, the CPU201performs call connection using the SIP connection process. The method of call connection using the SIP connection process will be described hereinafter.

Then, in a step S309, it is determined, based on the call connection established in the step S308, whether or not high-speed connection to the transmission destination apparatus is possible. Whether or not high-speed connection is possible can be determined based on a digital information signal (DIS) in T.38 (or T.30) connection processing. Information on the capabilities of the transmission destination apparatus is sent by a T.38 (or T.30) DIS from a recipient apparatus.FIG. 4shows an example of the contents of the DIS. As shown inFIG. 4, the DIS is formed by bit strings, and each of the bit strings is assigned a function. For example, bit3(third bit) is indicative of a T.38 capability. When the bit3has a value of 1, it is determined that the recipient apparatus is a T.38-based apparatus.

In the step S309, the CPU201determines whether or not the bit3of the received DIS is equal to 1 to thereby determine whether or not high-speed connection is possible. If it is determined that high-speed connection is possible, the CPU201proceeds to a step S310. On the other hand, if it is determined that high-speed connection is impossible, the CPU201proceeds to a step S312.

In the step S310, the CPU201determines the capabilities of the transmission destination apparatus based on the DIS. In general, when a function is extended, it is possible to extend a field of the DIS using an identification bit. By performing the function extension, information on the capability of transmission of a color image data or a hyper-resolution image of 600 dpi or higher is exchanged using the DIS. InFIG. 4, extended fields of bit64(64th bit) et seq. are used as information on transmission of color image data, and bit69(69th bit) is indicative of whether or not a color image receiving function is provided. If the bit69is equal to 1, it is determined that the color transmission capability is provided.

Further, recently, the DIS has been configured to enable resolution extension. Conventionally, an image for facsimile transmission can have one of four resolutions, i.e. 100×200 dpi, 200×200 dpi, 200×400 dpi, and 400×400 dpi. On the other hand, the use of the DIS makes it possible to select between resolutions from 600 dpi to 1200 dpi using extended fields of bit104(104th bit) et seq. of the DIS.

If it is determined in the step S310that the transmission destination apparatus is capable of transmitting a color image or a hyper-resolution image, the CPU201proceeds to a step S311. On the other hand, if it is determined that the transmission destination apparatus is not capable of transmitting a color image or a hyper-resolution image, the step S312et seq. are executed. That is, even if a sender has designated transmission of a color image or a hyper-resolution image, it is impossible to transmit the image to a transmission destination apparatus incapable of transmission of a color image or a hyper-resolution image.

In the step S311, the CPU201selects the image data for high-speed transmission (i.e. a color image or a hyper-resolution image), which was generated in the step S307, and transmits the selected image data (step S313). When the data transmission is completed (YES to the step S314), the CPU201causes the network interface section213to disconnect the line (step S315). Thus, when high-speed transmission is possible between the communication apparatus100and a transmission destination apparatus, the image data for high-speed transmission (i.e. a color image or a hyper-resolution image) generated in advance is selected, so that it is possible to perform facsimile transmission at a high speed for a small charge.

On the other hand, in the step S312, the CPU201selects the image data for low-speed transmission (i.e. a monochrome image or a low-resolution image), which was generated in the step S307, and transmits the selected image data in the step S313.

As described above, according to the present embodiment, a plurality of images (color or monochrome image and hyper-resolution or low-resolution images) are generated in advance in preparation for possibility of low-speed transmission, and after determining whether or not high-speed transmission is possible based on a transmission path and the capabilities of a transmission destination apparatus, one of the generated image is selected and transmitted. Consequently, in a case where only low-speed transmission is possible due to restriction of a communication path or the capabilities of a transmission destination apparatus, an image with a small data amount is transmitted, whereby it is possible to prevent the line from being occupied and to suppress a communication charge from being increased.

Next, a description will be given of a second embodiment of the present invention.

The second embodiment is distinguished from the above-described first embodiment only by a method of determining a transmission path (capabilities of a transmission destination apparatus) in the step S309inFIG. 3. Therefore, the same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the determination method in the step S309in the second embodiment, determination is performed not based on a T.38 (or T.30) DIS (digital information signal), but based on information from a signal in a SIP connection process.

First, a description will be given of the SIP connection process.

FIG. 5is a sequence diagram showing an example of a SIP connection process executed when a transmission destination apparatus is directly connected to a high-speed transmission path, such as an NGN.

As shown inFIG. 5, between the image communication apparatus100(T.38-based apparatus) and the image communication apparatus103(T.38-based apparatus), there is disposed a SIP server500for enabling exchange of signals between the apparatuses for the SIP connection process. The SIP server500is disposed e.g. at the HGW102or the NGN101appearing inFIG. 1, and is provided so as to perform address resolution (i.e. to derive the IP address of a transmission destination apparatus e.g. from a telephone number) in the SIP connection process.

Initiation of a call is performed using a signal called INVITE in the SIP connection process. The SIP server500having received the INVITE signal from the image communication apparatus100acquires the IP address of a transmission destination apparatus (the image communication apparatus103in the present example) from the telephone number or the like of the transmission destination apparatus contained in the signal. Then, the SIP server500sends a 100 Trying signal indicating that the call is in progress to the image communication apparatus100.

Then, the SIP server500notifies the image communication apparatus103as the transmission destination apparatus, using the INVITE signal, that an incoming call has been received. The image communication apparatus103having received the INVITE signal sends a 180 Ringing signal indicative of ringing to the SIP server500. The SIP server500transfers the 180 Ringing signal to the image communication apparatus100.

Next, after accepting the incoming call, the image communication apparatus103sends a 200 OK signal to the SIP server500. The SIP server500transfers the received signal to the image communication apparatus100.

Through the above-described sequential operations, a call is established between the image communication apparatuses100and103, and IP addresses of the respective image communication apparatuses100and103are determined. Thereafter, a session is established between the image communication apparatuses100and103in a point-to-point manner, and real-time facsimile transmission is performed by T.38 connection processing.

When the facsimile transmission is completed, the call established by the SIP connection process is disconnected using a BYE signal. The image communication apparatus100having received the signal sends the 200 OK signal to the image communication apparatus103, whereby the call is disconnected.

FIGS. 6A and 6Bshow examples of the INVITE signal and the 200 OK signal as a reply signal to the INVITE signal, which are exchanged in the SIP connection process.

FIG. 6Ashows the example of the INVITE signal, and a signal name is indicated in its leading line of character strings. A recipient (To) and a sender (From) are specified in the following character strings. In the INVITE signal, a portion starting with “V=0” is called SDP (session description protocol), and shows more detailed information on the signal.

FIG. 7is a sequence diagram showing an example of a SIP connection process executed in a case where the image communication apparatus106as a T.30-based apparatus is a transmission destination apparatus and low-speed transmission is to be performed via the T.38 gateway104.

It is assumed that the image communication apparatus100(T.38-based apparatus) is connected to the image communication apparatus106(T.30-based apparatus) via a communication path formed by the HGW102, the NGN101, the T.38 gateway104, and the PSTN105, inFIG. 1. In this case, a call connection process by SIP is performed between the image communication apparatus100, the SIP server500, and the T.38 gateway104. Since the T.38 gateway104, the PSTN105, and the image communication apparatus106are connected by the conventional analog line, the SIP connection process is converted to the PSTN call connection process by the T.38 gateway104. More specifically, the INVITE signal for the SIP connection process is converted to a PSTN call signal by the T.38 gateway104, and is then sent to the image communication apparatus106. When the image communication apparatus106responds to this, the T.38 gateway104detects an incoming signal from the image communication apparatus106, converts the signal to the 200 OK signal for the SIP connection process, and then transmits the 200 OK signal to the SIP server500. When a call is established through the above-described process, a session is established between the image communication apparatus100and the T.38 gateway104, whereby real-time communication by T.38 is performed between the image communication apparatus100and the T.38 gateway104. In doing this, the T.38 gateway104performs conversion of a T.38 procedure signal and a T.30 procedure signal, alternately.

The T.38 gateway104and the image communication apparatus106are connected to each other by a conventional T.30 procedure. The signal speed therebetween is 33.6 kbps maximum.

FIGS. 8A and 8Bshow examples of the INVITE signal and the 200 OK signal as a reply signal to the INVITE signal, which are exchanged in the SIP connection process.

FIG. 8Ashows the example of the INVITE signal, andFIG. 8Bshows the example of the 200 OK signal. For the most part, these signals each have the same general configuration as the corresponding one of the signals exemplified inFIGS. 6A and 6B, and therefore description thereof is omitted.

A character string starting with “o=” indicative of an originator (session originator) in the SDP (contents from “v=0) of the 200 OK signal indicates an apparatus as a converter of the SIP connection process. InFIG. 6B, the originator corresponds to a recipient apparatus, but inFIG. 8B, since conversion of the SIP connection process is performed by the T.38 gateway104, the character string at “o=” contains information indicative of the fact (“C-T38GateWay” in the present example). Determination as to a communication path can be performed by analyzing a signal contained in the character string at “o=”.

Thus, it is possible to determine a communication path (i.e. whether or not high-speed communication is possible) based on information of the SIP signal as a call connection process signal.

Although in the above-described embodiment, an image to be transmitted is selected based on whether or not high-speed communication is possible, this selection may be performed by a user. For example, a step of processing for displaying a screen900illustrated inFIG. 9, on the display and operation section203, may be additionally provided immediately before the step S312inFIG. 3so as to notify the user that large-amount image data is to be transmitted at a low speed. The screen900may be configured, as shown inFIG. 9, such that the user can select one of options “transmit large-amount data as it is”901, “transmit data converted to small-amount data”902, and “do not transmit”903.FIG. 10shows the flow of a process executed in this case. The same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 10is a flowchart of a facsimile transmission process executed by the image communication apparatus100according to a third embodiment of the invention. In the flowchart inFIG. 10, the same steps prior to the step S308as those inFIG. 3are omitted, and only the step S308et seq. are shown.

In the step S308, the CPU201initiates a call and performs call connection by the SIP connection process. Then, in the step S309, the CPU201determines, based on the call connection established in the step S308, whether or not high-speed connection to the transmission destination apparatus is possible. If it is determined that high-speed connection is possible, the CPU201proceeds to the step S310et seq.

On the other hand, if it is determined in the step S309that high-speed connection is impossible, the CPU201displays the screen900illustrated inFIG. 9, on the display and operation section203(step S320) and prompts the user to select a transmission operation to be performed thereafter. If the user selects transmission of large-amount data (i.e. the option “transmit large-amount data as it is”901) in a step S321, the step S310et seq. are executed. In other words, if the transmission destination apparatus is capable of transmission of large-amount data (YES to the step S310), the large-amount data is transmitted immediately.

On the other hand, if the user selects transmission of image data converted to small-amount data (i.e. the option “transmit data converted to small-amount data”902) in the step S321, the CPU201proceeds to the step S312, wherein the image data for low-speed transmission (i.e. the monochrome image or the low-resolution image), which was generated in the step S307, is transmitted.

Further, if the user selects not to transmit the data (i.e. selects the option “do not transmit”902) in the step S321, the CPU201proceeds to the step S315, and the line is disconnected, followed by terminating the process.

Besides the above-described method of prompting the user to select an operation in real time before execution of facsimile transmission, it is possible to employ a method of prompting the user to configure settings in advance.

For example, the CPU201may display a user's configuration screen1101illustrated in FIG.11A on the display and operation section203and causes the user to select whether to “permit” or “do not permit” low-speed transmission of large-amount data. If the option “permit”1102is selected on the user's configuration screen1101, low-speed transmission of large-amount data is performed without making an inquiry to the user before the start of the transmission.

On the other hand, if the option “do not permit”1103is selected, the user's configuration screen1101transitions to a screen1110illustrated inFIG. 11B, and the CPU201prompts the user to select whether to “permit” or “do not permit” processing for converting the large-amount data to small-amount data and then transmitting the small-amount data. If the option “permit”1111is selected on the screen1110, not the large-amount data (color image data or hyper-resolution image data), but the small-amount data (monochrome image data or low-resolution image data) is selected and transmitted. On the other hand, if the option “do not permit”1112is selected, data transmission is not performed. Thus, the user can configure an actual transmission operation, which makes it possible to specify the operation in a more detailed manner.

This application claims priority from Japanese Patent Application No. 2011-095913 filed Apr. 22, 2011, which is hereby incorporated by reference herein in its entirety.