JPH08274961A - Method and device for image transmission and resolution controller - Google Patents

Abstract

PURPOSE: To attain efficient still image transmission with an optimum resolution in response to application and display size of a received still image by receiving and sending a still image through command of the resolution by a receiver side. CONSTITUTION: An image pickup object original by a writings and picture camera section 202 is set in accordance with a marker of an original platen. Then an image is split into four pieces, a split image 1 is received and stored in a internal memory of a pattern composite section 204. Then a split input control section 203 controls the swing of the camera 202 to receive an image around the split image 2. Then the composite section 204 uses the marker to conduct matching calculation around the boundary of the split images 1, 2. Then the boundary is confirmed and the swing of the camera 202 is stopped and the image of the pattern 2 is stored in the composite section 204. The similar processing is applied to split images 3, 4 to receive the entire pattern with double resolution in horizontal nd vertical directions. The number of split images is set variably to attain image input with various resolution and optimum resolution required for the receiver side is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmission device, a multimedia communication terminal, an image transmission method applied to them, and a resolution control device. More specifically, the present invention relates to a space for transmitting image information. The present invention relates to an efficient method for determining resolution.

[0002]

2. Description of the Related Art In recent years, the development of image / voice compression coding technology and the spread of digital communication lines have been remarkable. Along with this, recommendations such as service rules and protocol rules for AV (Audio Visual) services such as video conferencing systems, multimedia multiplexing frame configuration rules, etc. have been prepared, and video telephone devices, video conferencing systems, etc. have been started. Various multimedia communication terminals have been proposed.

In these multimedia communication terminals, not only images of people (moving images) and voices of users, but also
By enabling the communication of documents and high-definition natural images (still images), more efficient communication has been realized.

Regarding still image information such as documents, drawings and photographs, there is an increasing demand for high-quality image input as the resolution of monitors increases. Scanners are widely used as a means for inputting high-resolution still images,
It has been pointed out that there are drawbacks such as the time required for data acquisition and the fact that only planar images can be input. Therefore,
In recent years, high-resolution cameras by various methods have been proposed as alternatives to scanners. Among them, the one that realizes high-resolution still image input using a standard resolution camera is drawing attention.

A screen (original) is a method for capturing a still image of higher resolution by using a camera of normal resolution.
Is divided into a plurality of parts, the images of the respective screens are input, and then the boundaries of the respective screens are aligned and combined into one screen (hereinafter, referred to as the
Method), a method of displacing the optical axis in units of a small number of pixels, capturing images, and then synthesizing each image (hereinafter, referred to as a second method).

FIG. 3 is a diagram for explaining division of image input by the first method based on screen division and subsequent joining processing. In the first method, one screen is divided into four screens with numbers 1 to 4 as shown in FIG. 3A, and the images of the divided screens are sequentially input as shown in FIG. 3B. After that, as shown in (c), the boundaries of the screens are aligned and combined into one screen.

FIG. 7 is a diagram for explaining the division of the image input by the second method based on the pixel shift and the combining processing thereafter. In this second method, as shown in FIG.
By inputting an image while shifting the optical axis for each minute pixel unit numbered 1 to 4 as in (a),
As shown in (b), one screen is divided into four screens and the images are input, and then the images are combined as shown in (c).

In the first method, the number of screen divisions and the division method are changed, and in the second method, the pixel unit to be shifted is changed.
The resolution can be made variable.

The still image information taken in by the multimedia communication terminal as described above is compression-encoded in the transmitting side multimedia communication terminal and then transmitted to the receiving side multimedia communication terminal through the communication line. To be done. On the receiving side, the still image information received from the transmitting side is subjected to decoding processing, and the image obtained by this is displayed on a monitor or output from a printer.

[0010]

The resolution of the monitor for displaying the still image received from the transmitting side and the size of the display window are various. For example, a monitor for a personal computer has a resolution of horizontal 640 × vertical 480, or a high resolution 800 × 600, 1024.
There are various types that can display up to × 768. Further, there are various display modes such as a case of displaying in a partial area (window) in each displayable area.
In many cases, the received still image is not only displayed on the monitor but also output to a printer.

However, in the conventional still image transmission method in the above-mentioned multimedia communication terminal, the use of the received still image, that is, whether to display it on the monitor or output it to the printer, is completely unknown at the sending side terminal. there were. Further, even when an image is displayed on the monitor, the display size (the number of pixels) cannot be known at all on the transmitting side.

Therefore, even if the monitor on the receiving side can display the image at a high resolution, if the low resolution image is transmitted, or conversely, the receiving side does not perform processing such as decimation, There is a drawback that a high resolution image that cannot display the screen may be transmitted. Further, when the received still image is output to the printer, the resolution is insufficient, so that only a rough image can be output.

Therefore, it is said that the receiving side may not be able to display or output the received still image with sufficiently high resolution, or that the transmission time and the transmission cost may be increased by transmitting the image with the higher resolution than necessary. There was a problem.

The present invention has been made in view of the above conventional problems, and it is possible to transmit image information at an optimum resolution according to the intended use of the received image on the receiving side and the required resolution. The purpose is to

[0015]

An image transmission method of the present invention is an image transmission method for transmitting image information through a communication line, and is instructed by resolution control information notified from a destination device of the image information. It is characterized in that the image information of the spatial resolution is generated and transmitted to the destination device.

Another feature of the present invention is that the low resolution image information is transmitted prior to the transmission of the image information.

Another feature of the present invention is an image transmission method for transmitting input image information via a communication line, wherein the destination device of the image information indicates the spatial resolution of the transmitted image information. A receiving step of receiving control information, a resolution determining step of determining the spatial resolution of the transmission image information based on the control information received in the receiving step, and image information of the spatial resolution determined in the resolution determining step. And an image input step of inputting.

Another feature of the present invention is that in the image input step, the entire screen is divided into a plurality of screens, the images are input, and then the images are joined to each other to increase the resolution. A split input control step of selecting a screen split input method corresponding to the spatial resolution determined in the resolution determination step,
According to the screen split input method selected in the split input control step, a split screen input step of inputting the images of the split screens and a joining step of joining the split screen images input in the split screen input step It is composed of and.

Another feature of the present invention is that in the image input step, an image having a higher resolution is obtained by inputting images of a plurality of screens by shifting pixels by a small unit and then synthesizing the images. Pixel shift input control step for inputting information, selecting a pixel shift input method corresponding to the spatial resolution determined in the resolution determination step, and pixel shift input method selected in the pixel shift input control step According to the above, a pixel shift screen input step of inputting the images of the respective screens and a synthesizing step of synthesizing the images of the respective screens input in the pixel shift screen inputting step.

Another feature of the present invention is that the image input step includes a variable input step of inputting the image information at a variable resolution, and a resolution conversion process for the image information input in the variable input step. And the variable input step and the resolution converting step are performed, the input resolution in the variable input step and the conversion in the resolution converting step are performed according to the spatial resolution determined in the resolution determining step. And a resolution conversion allocation step for controlling the combination with the resolution.

The image transmission apparatus of the present invention is an image transmission apparatus for transmitting image information via a communication line, and the space of the image information is based on the resolution control information notified from the destination apparatus of the image information. Resolution determining means for determining the resolution, image information generating means for generating image information of the spatial resolution determined by the resolution determining means, and image for transmitting the image information generated by the image generating means to the destination device. An information transmission means is provided.

The resolution control device of the present invention is a resolution control device for controlling the resolution of image information transmitted via a communication line, and is based on the resolution control information notified from the destination device of the image information. It is characterized in that a resolution control means for controlling the spatial resolution of the image information transmitted to the destination device is provided.

Another feature of the present invention is that the resolution control means includes receiving means for receiving control information indicating a spatial resolution of transmission image information from a destination device of the image information, and the receiving means. It is characterized by further comprising: resolution determining means for determining the spatial resolution of the image information based on the received control information; and control means for controlling the spatial resolution of the image information according to the content determined by the resolution determining means. It is a thing.

[0024]

According to the present invention configured as described above, the spatial resolution required by the destination device of the image information is notified by the resolution control information, and the image of the spatial resolution indicated by the notified resolution control information is displayed. Since the information is generated and transmitted to the transmission destination device, it is possible to transmit the image information of the resolution based on the resolution instruction from the reception side (transmission destination) of the image information.

When the image information having an arbitrary spatial resolution is generated at the image information input stage, the spatial resolution required by the destination device of the image information is notified by the resolution control information. Since the image information is input with the spatial resolution indicated by the resolution control information and the input image information is transmitted to the destination device, the resolution based on the resolution instruction from the receiving side of the image information. It is possible to input and transmit the image information of.

For example, when the image information is input according to the screen division input and the variable resolution input by the joining process, the screen division input method is selected according to the resolution control information notified from the destination device of the image information. Therefore, it is possible to control the screen division input method of the transmission image information based on the resolution instruction from the image information receiving side.

When the image information is input according to the pixel shift input and the variable resolution input by the synthesizing process, the pixel shift input method is selected according to the resolution control information notified from the destination device of the image information. As a result, it becomes possible to control the pixel shift input method of the transmission image information based on the resolution instruction from the image information receiving side.

Further, when the image information is input according to the variable resolution input and the resolution conversion processing, the input resolution and the conversion resolution are set according to the resolution control information notified from the destination device of the image information. Since the combination is selected, it is possible to control the combination of variable resolution input and resolution conversion based on the resolution instruction from the receiving side of the image information.

According to the image transmission device of the present invention, the spatial resolution required by the destination device of the image information is notified by the resolution control information, and the spatial resolution determined based on the notified resolution control information is used. Since the image information is generated and transmitted to the destination device, it is possible to transmit the image information having the resolution based on the resolution instruction from the receiving side of the image information.

According to the resolution control device of the present invention, the spatial resolution requested by the destination device of the image information is notified by the resolution control information, and the spatial resolution is controlled according to the instruction by the notified resolution control information. Therefore, it is possible to control the resolution of the transmitted image information based on the resolution instruction from the receiving side of the image information.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 2 shows an example of the overall configuration of the multimedia communication terminal according to this embodiment.

In FIG. 2, reference numeral 201 denotes one of the image inputting means of the present apparatus, which is a camera section for inputting a self-portrait (a subject image on the self-apparatus side). 202 is another one of the image input means of the present apparatus, and is a document camera unit for inputting images such as drawings, maps and documents. Document camera unit 202
Has a zoom function and a swing function, and is capable of zooming and changing the shooting direction.

Reference numeral 203 denotes a split input control unit, which controls the zoom function and the swing function of the document camera unit 202 in order to realize image input by screen division described later. Reference numeral 204 denotes a screen joining unit, which is used for the resolution control unit 2 for the split screen image input from the document camera unit 202.
The joining process described later is performed according to the instruction from 21.

Reference numeral 205 denotes a display unit which is one of image output means, and is used for displaying an input image from the camera unit 201 or the screen joining unit 204 or an image received from a partner device, and for instructing various operations. Display the operation screen, etc. A printer unit 206, which is another one of the image output means, prints an input image from the camera unit 201 or the screen joining unit 204 or an image received from the partner device.

Reference numeral 207 denotes an image input interface unit which performs switching processing of image input means (camera unit 201, document camera unit 202) and the like in response to an instruction from the system control unit 218. An image output interface unit 208 is an image output unit (display unit 205, printer unit 206).
Switching processing and the like. 209 is an image editing unit,
In accordance with an instruction from the system control unit 218, each processing such as so-called picture-in-picture processing, screen freeze processing, and display image selection / combination processing is executed.

An image coding / decoding unit 210 includes an image coding unit 210a for coding the transmission image information and an image decoding unit 210b for decoding the reception image information.
It is composed of This image encoding / decoding unit 2
Reference numeral 10 corresponds to a moving image coding system and a still image coding system.

Reference numeral 211 designates a handset section which is one of the voice input / output means of this apparatus, 212 a microphone section which is one of the voice input means of this apparatus, and 213 a speaker which is one of the voice output means of this apparatus. It is a department. Reference numeral 214 denotes a voice input / output interface section, which receives instructions from the system control section 218, so-called echo cancellation processing, tone generation processing such as dial tone, ringing tone, busy tone, and ring tone, or switching processing of voice input / output means. Each processing such as voice synthesis processing is performed.

Reference numeral 215 denotes a voice encoding / decoding unit, which has a voice encoding unit 215a for encoding transmission voice information and a voice decoding for performing reception voice information decoding in accordance with an instruction from the system control unit 218. And a part 215b. An operation unit 216 is composed of a keyboard, a touch panel, etc. used for inputting control information for performing overall control of the apparatus.

Reference numeral 217 denotes a demultiplexing unit, which multiplexes image information, audio information, and control information generated on its own side in transmission frame units, supplies them to the line interface unit 222, and receives them at the line interface unit 222. The received frame from the partner device is separated into image information, audio information, and control information, which are supplied to the image encoding / decoding unit 210, the audio encoding / decoding unit 215, and the system control unit 218, respectively.

The system control unit 218 has a CPU, an R
It is provided with an OM, a RAM, an auxiliary storage device, etc., and monitors the states of the above-mentioned respective parts, controls the entire device, creates an operation / display screen according to the states of the respective parts, and executes an application program. This system control unit 218
A resolution control information generation unit 219 and a reception resolution control information recognition unit 220 are included therein.

The resolution control information generating section 219 is used when this apparatus is the image information receiving side,
Whether the received image is displayed on the display unit 205 or the printer unit 206
Control information (screen division number and division method) for requesting the required resolution to the transmission side terminal of the image information according to the output format to the display unit 205, the display mode on the display unit 205, or the like. Control information for instructing the.

Further, the reception resolution control information recognition section 220
Is used when the apparatus is the image information transmission side, and detects the reception of control information for requesting the resolution of the image information transmitted from the image information reception side.

Next, the resolution control unit 221 determines the resolution of the transmitted still image based on the resolution control information detected by the reception resolution control information recognition unit 220, and the divided input control unit 203, the screen joining unit 204, Image editing unit 20
9. It controls the image coding unit 210a. The line interface unit 222 controls the communication line 223 according to an ISDN (Integrated Services Digital Network) user network interface.

The division input control unit 203, the screen joining unit 204, the system control unit 218, and the resolution control unit 221 constitute a resolution control device according to an embodiment of the present invention.

Next, the basic communication operation of the multimedia communication terminal configured as described above will be explained. When the present multimedia communication terminal serves as the image information transmitting side, an image input from the camera unit 201 or the document camera unit 202 passes through the image input interface unit 207, the screen joining unit 204, and the image editing unit 209 to form an image. It is input to the encoding unit 210a. Also, the handset unit 2
The voice input from the microphone 11 or the microphone unit 212 is input to the voice encoding unit 215a through the voice input / output interface unit 214.

Then, the input image information coded by the image coding unit 210a and the input voice information coded by the voice coding unit 215a are multiplexed with various control information by the demultiplexing and multiplexing unit 217, and the line is multiplexed. It is sent to the communication line 223 by the interface unit 222.

On the other hand, when the present multimedia communication terminal is the receiving side of the image information, the received signal received from the transmitting side via the communication line 223 is the line interface section 2.
It is input to the demultiplexing / multiplexing unit 217 through 22 and is separated into image information, audio information, and various control information here. The separated information is input to the image decoding unit 210b, the audio decoding unit 215b, and the system control unit 218, respectively.

The received image information decoded by the image decoding unit 210b is displayed on the display unit 205 through the image editing unit 209 and the image output interface unit 208 or output to the printer unit 206. The received voice information decoded by the voice decoding unit 215b is output to the handset unit 211 or the speaker unit 213 through the voice input / output interface unit 214.

The image encoding / decoding unit 210 includes a moving image encoder / decoder and a still image encoder / decoder, and an encoding method for moving image information (for example,
H.261, MPEG: Moving Picture Image Coding Experts Gro
up) and encoding method for still image information (eg JPEG: J
oint Photographic Coding Experts Group) is adaptively selected to perform efficient compression / decompression processing.

When the present multimedia communication terminal is the sender of image information, it is multiplexed (or dedicated control) with the received signal sent from the receiver (destination) terminal prior to the transmission. The control information for controlling the resolution of the still image information to be transmitted among the various control information (notified via the communication line) is received by the reception resolution control information recognition unit 2
Identify by 20. Then, the information of the resolution requested by the reception side terminal identified in this way is provided to the resolution control unit 2
21 is notified.

The resolution control unit 221 determines the resolution of the image information according to the request of the receiving side terminal, and the division input control unit 203, the screen joining unit 204, the image editing unit 209, and the image coding unit 210a determine the resolution. Specify the resolution.

By the way, in the present multimedia communication terminal, it is possible to input still images of variable resolution, that is, to capture still images at different resolutions by a predetermined process. Specifically, the screen (original) is divided into multiple screens according to the required resolution, the images of each divided screen are captured, and then these images are joined to obtain a still image. It is possible to change and capture a still image.

For example, when the screen is divided into four parts (two in the horizontal direction and two in the vertical direction), the state of the screen division and the joining process is as shown in FIG. 3, but the screen is divided into four parts in this way. In this case, the resolution is doubled in both the horizontal and vertical directions. By changing the number of divisions of this screen and the division method (division pattern), still images of various resolutions can be input.

The above-described screen division input and joining processing of still images will be described in detail below. The document to be photographed by the document camera unit 202 is set according to the marker provided on the document table. Then, in the case of dividing the screen into four as shown in FIG. 3, first, the image of the divided screen 1 is input and stored in the internal memory (not shown) of the screen joining unit 204.

Subsequently, the division input control section 203 controls the swing of the document camera section 202 to input the image near the division screen 2. Here, in the screen joining unit 204, a matching calculation near the boundary between the divided screen 1 and the divided screen 2 is performed using the above-mentioned marker. Then, when the boundary position is determined, the swing of the document camera unit 202 is stopped, and the image of the split screen 2 is stored in the internal memory of the screen joining unit 204.

Further, the same processing is executed for the divided screens 3 and 4, so that the whole screen having double the resolution in both the horizontal and vertical directions can be captured. By setting the number of screen divisions to be variable, images of various resolutions can be input. For reference, FIG. 4 (a) shows how the screen is divided when achieving 3 times the resolution in both the horizontal and vertical directions. FIG. 4 (a) shows the state of dividing the screen when realizing 4 times the resolution. Shown in b).

Next, the operation relating to the determination of the resolution (the number of screen divisions and the division method) which is the most characteristic of this embodiment will be described. First, before transmitting the still image information,
Resolution control information indicating the resolution required at the terminal for receiving the still image (for example, the resolution that matches the display area when displaying the received still image on the monitor, and the resolution that corresponds to the output size when outputting to the printer) , Is transmitted from the receiving side terminal to the transmitting side terminal.

In the still image transmitting side terminal, control information for controlling the resolution of the still image information to be transmitted is identified from among various control information multiplexed in the received signal from the still image receiving side terminal. To do. Then, by controlling the still image input according to the resolution notified by the resolution control information, the still image is captured at the resolution requested by the receiving side terminal and the still image is transmitted.

Regarding the above-mentioned resolution control operation, the detailed operation of each section shown in FIG. 2 will be described with a specific example as follows. Note that, here, the split input control unit 203 and the screen joining unit 204 join the entire screen to input an image without splitting the screen, and split the screen into a plurality of images, and then join the images 4 It is assumed that it is possible to perform split screen input / join, nine split screen input / join, and 16 split screen input / join. That is, the standard resolution is doubled both horizontally and vertically,
It is assumed that image input is realized with four kinds of resolutions, that is, three times and four times the resolution.

FIG. 1 is a flowchart showing the resolution control operation of the still image information described above. In FIG. 1, first, in step S1, prior to the transmission of a still image, the resolution control information indicating the resolution required at the receiving side terminal is sent from the receiving side (destination) terminal of the still image to the communication line 22.
3 is received by the terminal of the side (sender) of the still image.

The resolution control information transmitted from the terminal of the still image receiving side to the terminal of the transmitting side is binary 00, 01,
10 and 11 are associated with the standard resolution, the double resolution, the triple resolution, and the quad resolution, respectively. Note that a dedicated control line may be used as the transmission path of the resolution control information, but here, it is assumed that image information and audio information and the above-mentioned resolution control information are multiplexed and transmitted.

Next, in step S2, the reception information received from the communication line 223 is input to the demultiplexing / multiplexing unit 217 through the line interface unit 222. Then, in the demultiplexing / multiplexing unit 217, the received information is demultiplexed into image information, audio information, and control information. Of the information thus separated, the control information is sent to the reception resolution control information recognition section 220 in the system control section 218.

The reception resolution control information recognition section 220 is
In step S3, the reception control information sent from the demultiplexing / multiplexing unit 217 is checked, and the arrival of the information for controlling the resolution of the still image to be transmitted to the reception side terminal (information indicating the resolution required on the reception side) To detect. Then, it decodes the control information and notifies the resolution control unit 221 of information indicating the requested resolution.

The resolution control unit 221 controls the division input control unit 203 and the screen joining unit 204 based on the information notified from the reception resolution control information recognition unit 220, thereby determining the resolution of the still image captured in the apparatus. Have control. Specifically, when the reception resolution control information recognition unit 220 notifies the requested resolution of the receiving side terminal, the resolution control unit 221 determines the resolution of the still image to be captured based on the notification content. Then, the split input control unit 203
Also, the screen joining unit 204 is instructed about the number of screen divisions and the division size.

That is, the resolution control unit 221 discriminates what the received resolution control information is in step S4, and determines the number of divisions and the division size of the screen according to the discrimination result according to the division input control unit 203 and the screen. Instruct the joint portion 204. Received resolution control information is "00" (standard resolution)
In the case of, the process proceeds to step S5, and an instruction is given to input an image without dividing the screen. Received resolution control information is "0"
In the case of 1 "(double the horizontal and vertical resolutions with respect to the standard resolution), the process proceeds to step S6 and the screen is divided into four, and an instruction is given to input an image.

If the received resolution control information is "10" (triple resolution in both horizontal and vertical directions), step S7.
Then, the screen is divided into 9 parts and the image input is instructed. If the received resolution control information is "11" (4 times the horizontal and vertical resolutions), the process proceeds to step S8, and the screen is divided into 16 parts and an image is input.

When the resolution control unit 221 issues an instruction as described above, steps S5 to S are executed in response to the instruction.
8 is performed. That is, the split input control unit 203 controls zooming and swinging of the document camera unit 202 by the method described above, and the still image is input. Then, in the next step S9, the screen joining portion 2
By 04, the split screen is joined.

Next, in step S10, the image information subjected to the above-mentioned joining processing is input to the image coding section 210a through the image editing section 209 and subjected to the compression coding processing.
Here, the image encoding unit 210a is notified of the information indicating the image size together with the information indicating whether the image to be encoded is a moving image or a still image. According to this, one of the moving image encoder and the still image encoding is selected, and the optimum compression encoding process is executed.

Then, in step S11, the compression-coded image information is multiplexed with other audio information and various control information by the demultiplexing / multiplexing unit 217, and then the line interface unit 222 passes through the communication line 223. Is transmitted to the receiving side terminal. As a result, it is possible to transmit a still image with the optimum resolution according to the application of the still image and the display area in the receiving side terminal.

As described above, in the first embodiment, when the image information is transmitted, the resolution control information sent from the receiving side terminal is detected at the transmitting side terminal prior to the transmission of the image information. Recognize and determine the resolution of the image to be transmitted, that is, the number of input divisions of the screen according to this Then, screen division input and joining processing of images according to the determined contents are executed, and image information obtained by this is compression-encoded and transmitted to the receiving side terminal.

Therefore, according to the present embodiment, the optimum resolution requested by the receiving terminal is selected according to the application of the image at the receiving terminal and the size of the display area, and the image is displayed at this selected resolution. It is taken in by the sending side terminal and is transmitted to the receiving side terminal. Therefore, there is a problem that the image received at the receiving terminal cannot be displayed in sufficiently high definition as in the conventional case, or that the transmission time and the transmission cost are increased by transmitting the image with a higher resolution than necessary. This can be prevented, and image transmission can be efficiently performed.

In the first embodiment, the case where the resolution instruction information is transmitted from the receiving side (transmission destination) to the transmitting side (transmission source) prior to the transmission of the still image has been described. First, a transmission image information is confirmed from the transmission side to the reception side by transmitting a low-resolution image that does not require a transmission cost and can confirm the type of the image. After that, if necessary, the resolution instruction information is transmitted from the reception side to the transmission side, and the image of the required resolution is retransmitted to the reception side according to the instruction information. It is also possible to realize the resolution instruction according to the characteristics. It may also be combined with hierarchical coding.

In the first embodiment, the number of screen divisions is four (two for both horizontal and vertical),
9 divisions (3 divisions for both horizontal and vertical), 16 divisions (horizontal
Only the case of selectively using any of the four vertical divisions) has been described, but the number of divisions is not limited to this. Furthermore, the divided input pattern may be variable.

In the first embodiment, the case where the image transmission method according to the present invention is applied to a multimedia communication terminal has been described, but it goes without saying that the present invention can be applied to all other image transmission devices. .

In the first embodiment, the case where the desired resolution conversion is realized by controlling the number of screen divisions at the image input stage has been described. However, the resolution conversion processing after capturing a still image is By combining them, it is possible to obtain an image with a required resolution. It is also possible to obtain an image with a desired resolution by performing the resolution conversion processing independently.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 6 shows an example of the overall configuration of the multimedia communication terminal according to this embodiment.

In FIG. 6, the same parts as those of the multimedia communication terminal shown in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. Reference numeral 602 is one of the image input means of the present apparatus, and is a document camera unit for inputting images such as drawings, maps and documents. The document camera unit 602 has a so-called minute pixel shift function.

Reference numeral 603 denotes a pixel shift input control unit, which executes pixel shift control of the document camera unit 602 in order to realize image input by pixel shift described later. 604
Is a screen synthesizing unit, and a resolution control unit 621 is provided for an image by pixel shifting input from the document camera unit 602.
According to the instruction from, the synthesizing process described later is performed.

Reference numeral 618 denotes a system control unit having a CPU, a ROM, a RAM, an auxiliary storage device, etc., which monitors the state of each section of the apparatus, controls the apparatus as a whole, and operates / displays a screen according to the state of each section. And the execution of application programs. The system control unit 618 has a resolution control information generation unit 619 and a reception resolution control information recognition unit 620 inside.

The resolution control information generating section 619 is used when this apparatus is the image information receiving side.
Whether the received image is displayed on the display unit 205 or the printer unit 206
Control information for instructing the required resolution to the transmission side terminal of the image information (instructing the shift unit of the pixel) depending on whether it is output to Control information for) is generated.

Further, the reception resolution control information recognition section 620
Is used when the apparatus is the image information transmission side, and detects the reception of control information for requesting the resolution of the image information transmitted from the image information reception side.

The resolution control unit 621 determines the resolution of the transmitted still image based on the resolution control information detected by the reception resolution control information recognition unit 620, and the pixel shift input control unit 603, the screen synthesis unit 604, Image editing unit 20
9. It controls the image coding unit 210a.

The pixel shift input control section 60 described above is used.
3, the screen compositing unit 604, the system control unit 618, and the resolution control unit 621 constitute a resolution control device according to another embodiment of the present invention.

When the present multimedia communication terminal is the image information transmission side, the reception resolution control information recognition section 62 is used.
0 is the transmission of various control information that has been multiplexed (or notified via a dedicated control line) to the reception signal sent from the receiving side (destination) terminal prior to the transmission of the image information. Control information for controlling the resolution of the still image information to be identified is identified. Then, the information of the resolution requested by the receiving side terminal identified in this way is provided to the resolution control unit 62.
Notify 1.

The resolution control unit 621 determines the resolution of the image information in response to the request of the receiving side terminal, and the pixel shift input control unit 603, the screen synthesizing unit 604, the image coding unit 21.
0a indicates the resolution determined above.

By the way, in the present multimedia communication terminal, it is possible to input still images of variable resolution, that is, to capture still images at different resolutions by a predetermined process. More specifically, after capturing image information while shifting the pixels that make up the screen by a small unit according to the required resolution, and combining these image information to obtain a still image, the resolution is changed and the still image is changed. Can be captured.

For example, when the image input by four screens is performed by shifting by half pixel (1/2 pixel), the state of each screen input and the combining process is as shown in FIG. When the screen is divided into four by shifting by / 2 pixels each, the resolution is doubled in both the horizontal and vertical directions. By changing the minute unit of the pixel to be shifted, it is possible to input still images of various resolutions.

The above-described pixel shift input and combination processing of the still image will be described in detail below. In the case of shifting by 1/2 pixel as shown in FIG. 7, the image of the split screen 1 is first input and stored in the internal memory (not shown) of the screen compositing unit 604.

Next, the pixel shift input control unit 603 controls the pixel shift amount of the document image camera unit 602, inputs the image of the split screen 2 shifted by 1/2 pixel in the horizontal direction, and inputs it to the screen synthesis unit 604. Stored in the internal memory of.

Further, the same processing is executed for the divided screens 3 and 4, so that the whole screen having the double resolution in both the horizontal and vertical directions is captured. By variably setting the pixel shift amount, it is possible to input images with various resolutions. For reference, FIG. 8A shows the state of pixel shift input in the case of realizing the triple resolution in both the horizontal and vertical directions, and the state of the pixel shift input in the case of realizing the quadruple resolution. 8
It shows in (b).

Next, the operation relating to the determination of the resolution (pixel shift unit), which is the most characteristic feature of this embodiment, will be described. First, prior to transmitting the still image information, the resolution required by the terminal for receiving the still image (for example, if the received still image is to be displayed on the monitor, the resolution that matches the display area, or if it is to be output to a printer, output. The resolution control information indicating the resolution according to the size is transmitted from the receiving side terminal to the transmitting side terminal.

In the still image transmitting side terminal, control information for controlling the resolution of the still image information to be transmitted is identified from among various control information multiplexed in the received signal from the still image receiving side terminal. To do. Then, by controlling the still image input according to the resolution notified by the resolution control information, the still image is captured at the resolution requested by the receiving side terminal and the still image is transmitted.

Regarding the resolution control operation as described above, the detailed operation of each section shown in FIG. 6 will be described with a specific example as follows. Note that, here, the pixel shift input control unit 603 and the screen compositing unit 604 compose the whole screen input in which image input is performed without pixel shift, and the image input in which pixel shift is performed and then each image is synthesized. It is assumed that it is possible to perform 1/2 pixel shift input / synthesis, 1/3 pixel shift input / synthesis, and 1/4 pixel shift input / synthesis. That is, it is assumed that the image input is realized with four kinds of resolutions of the standard resolution and the resolutions of double, triple and quadruple in the horizontal and vertical directions.

FIG. 5 is a flowchart showing the resolution control operation of the still image information described above. In FIG. 5, first, in step S1, prior to the transmission of a still image, the resolution control information indicating the resolution required at the receiving side terminal is transmitted from the receiving side (destination) terminal of the still image to the communication line 22.
3 is received by the terminal of the side (sender) of the still image.

The resolution control information transmitted from the terminal of the still image receiving side to the terminal of the transmitting side is binary numbers 00, 01,
10 and 11 are associated with the standard resolution, the double resolution, the triple resolution, and the quad resolution, respectively. Note that a dedicated control line may be used as the transmission path of the resolution control information, but here, it is assumed that image information and audio information and the above-mentioned resolution control information are multiplexed and transmitted.

Next, in step S2, the reception information received from the communication line 223 is input to the demultiplexing / multiplexing unit 217 through the line interface unit 222. Then, in the demultiplexing / multiplexing unit 217, the received information is demultiplexed into image information, audio information, and control information. Of the information thus separated, the control information is sent to the reception resolution control information recognition section 620 in the system control section 618.

The reception resolution control information recognition section 620 is
In step S3, the reception control information sent from the demultiplexing / multiplexing unit 217 is checked, and the arrival of the information for controlling the resolution of the still image to be transmitted to the reception side terminal (information indicating the resolution required on the reception side) To detect. Then, the control information is decoded and information indicating the requested resolution is notified to the resolution control unit 621.

The resolution control unit 621 controls the pixel shift input control unit 603 and the screen compositing unit 604 based on the information notified from the reception resolution control information recognition unit 620 to thereby obtain the resolution of the still image captured in the apparatus. Are in control. Specifically, when the reception resolution control information recognition unit 620 notifies the requested resolution of the receiving side terminal, the resolution control unit 621 determines the resolution of the still image to be captured based on the notification content. Then, the pixel shift input control unit 603 and the screen compositing unit 604 are instructed on the pixel shift unit and the image size.

That is, the resolution control unit 621 determines in step S4 what the received resolution control information is, and the pixel shift unit and the image size are determined by the pixel shift input control unit 603 and the screen compositing unit according to the determination result. Part 604
Instruct. If the received resolution control information is "00" (standard resolution), the process proceeds to step S5, and an instruction is made to input an image without performing pixel shift. If the received resolution control information is “01” (double the horizontal and vertical resolutions with respect to the standard resolution), the process proceeds to step S6, and the pixel shift unit is set to 1/2 pixel and pixel shift input is performed. To do.

If the reception resolution control information is "10" (triple resolution in both horizontal and vertical directions), step S7.
Then, the process shifts to (1) to set the pixel shift unit to 1/3 pixel and instruct to perform pixel shift input. Received resolution control information is "1"
In the case of 1 "(4 times the resolution in both horizontal and vertical directions), the process proceeds to step S8, and the pixel shift unit is instructed to perform pixel shift input.

When the resolution controller 621 issues an instruction as described above, steps S5 to S are executed in response to the instruction.
8 is performed. That is, the pixel shift input control unit 603 controls the pixel shift amount of the document camera unit 602 by the method described above, and the still image is input. Then, in the next step S9, the screen synthesizing unit 604 performs a synthesizing process for each screen.

Next, in step S10, the image information that has been subjected to the above-described combining processing is input to the image encoding section 210a through the image editing section 209, and compression encoding processing is performed.
Here, the image encoding unit 210a is notified of the information indicating the image size together with the information indicating whether the image to be encoded is a moving image or a still image. According to this, one of the moving image encoder and the still image encoding is selected, and the optimum compression encoding process is executed.

Then, in step S11, the compression-encoded image information is multiplexed with other audio information and various control information by the demultiplexing / multiplexing unit 217, and then the line interface unit 222 passes it through the communication line 223. Is transmitted to the receiving side terminal. As a result, it is possible to transmit a still image with the optimum resolution according to the application of the still image and the display area in the receiving side terminal.

As described above, in the second embodiment, when image information is transmitted, the resolution control information sent from the receiving side terminal is detected at the transmitting side terminal prior to the transmission of the image information. -Recognize and determine the resolution of the image to be transmitted accordingly, that is, the pixel shift input unit. Then, the pixel shift input and the combining process of the image according to the contents of this determination are executed, and the image obtained by this is compression-encoded and transmitted to the receiving side terminal.

Therefore, according to the present embodiment, the optimum resolution requested by the receiving terminal is selected according to the use of the image at the receiving terminal and the size of the display area, and the image is displayed at this selected resolution. It is taken in by the sending side terminal and is transmitted to the receiving side terminal. Therefore, there is a problem that the image received at the receiving terminal cannot be displayed in sufficiently high definition as in the conventional case, or that the transmission time and the transmission cost are increased by transmitting the image with a higher resolution than necessary. This can be prevented, and image transmission can be efficiently performed.

In the second embodiment, the case where the resolution instruction information is transmitted from the receiving side (transmission destination) to the transmission side (transmission source) prior to the transmission of the still image has been described. First, a transmission image information is confirmed from the transmission side to the reception side by transmitting a low-resolution image that does not require a transmission cost and can confirm the type of the image. After that, if necessary, the resolution instruction information is transmitted from the reception side to the transmission side, and the image of the required resolution is retransmitted to the reception side according to the instruction information. It is also possible to realize the resolution instruction according to the characteristics. It may also be combined with hierarchical coding.

In the second embodiment, the unit of pixel shift is 1/2 pixel unit (4 input screens), 1/3 pixel unit (9 input screens), 1/4 pixel. Although only the case of selectively using any of the units (the number of input screens is 16) has been described, the pixel shift unit (the number of input screens) is not limited to this.

In the second embodiment, the case where the image transmission method according to the present invention is applied to a multimedia communication terminal has been described, but it goes without saying that the present invention can be applied to all other image transmission devices.

In the second embodiment, the case where the desired resolution conversion is realized by controlling the pixel shift unit in the image input stage has been described.
It is also possible to obtain an image with a required resolution by combining with a resolution conversion process after capturing a still image. It is also possible to obtain an image with a desired resolution by performing the resolution conversion processing independently.

It goes without saying that the image transmission method of the present invention can also be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0111]

As described above in detail, according to the image transmission method of the present invention, the image information of the spatial resolution indicated by the resolution control information notified from the destination device of the image information is generated, and this is generated. Since the image information is transmitted to the destination device, it is possible to generate and transmit the image information at the resolution based on the resolution instruction from the receiving side (destination) of the image information, and the use of the received image information on the receiving side. It is possible to realize efficient image transmission with the optimum resolution required according to the display size and the like.

According to another feature of the present invention, based on the receiving step of receiving the control information indicating the spatial resolution of the transmitted image information from the destination apparatus of the image information, and the control information received in the receiving step. The apparatus further comprises a resolution determining step of determining a spatial resolution of the transmitted image information, and an image input step of inputting image information of the spatial resolution determined in the resolution determining step. Since the control information indicating the required spatial resolution is received and the image information of the spatial resolution based on this control information is input and transmitted, the resolution information is received based on the resolution instruction from the receiving side of the image information. Image information can be input and transmitted at the resolution, and it is the optimum required depending on the use and display size of the received image information on the receiving side. It is possible to achieve efficient image transmission by the resolution.

According to another feature of the present invention, a split input control step of selecting a screen split input method corresponding to the spatial resolution determined in the resolution determination step, and a screen split selected in the split input control step. According to the input method, the image input step is configured by a split screen input step of inputting each split screen image and a joining step of joining the split screen images input in the split screen input step. Receives the control information indicating the spatial resolution required by the destination device of the image information, and selects the resolution of the transmitted image, that is, the screen division input method (screen division number, etc.) based on this control information. Since the screen split input and splicing processing are performed using this method and the image thus input is transmitted to the receiving side, the resolution instruction from the receiving side is displayed. Can be input and transmission of the image information with a resolution that is based on, it is possible to realize efficient image transmission by the optimum resolution required depending on the application and the display size and the like of the received image information at the receiving side.

According to another feature of the present invention, the pixel shift input control step of selecting a pixel shift input method corresponding to the spatial resolution determined in the resolution determination step and the pixel shift input control step selected in the pixel shift input control step. According to the pixel shift input method, the image input step is configured by a pixel shift screen input step of inputting an image of each screen and a synthesizing step of synthesizing the image of each screen input in the pixel shift screen input step. Accordingly, the control information indicating the spatial resolution required in the image information transmission destination device is received, and the resolution of the transmission image, that is, the pixel shift input method (pixel shift unit, etc.) is determined based on this control information. Select and perform pixel shift input and synthesis processing, and transmit the image thus input to the receiving side. Therefore, the image information can be input and transmitted at the resolution based on the resolution instruction from the receiving side, and the efficient image with the optimum resolution required according to the use and display size of the receiving image information at the receiving side. Transmission can be realized.

According to another feature of the present invention, a variable input step of inputting image information at a variable resolution, a resolution conversion step of performing resolution conversion processing on the image information input in the variable input step, A resolution for controlling the combination of the input resolution in the variable input step and the conversion resolution in the resolution conversion step according to the spatial resolution determined in the resolution determination step when performing the processing of the variable input step and the resolution conversion step. The image assigning step and the conversion assigning step constitute the image inputting step, whereby the control information indicating the spatial resolution required by the destination device of the image information is received, and the input resolution and the subsequent steps are received based on this control information. Variable resolution input by optimal combination by controlling both conversion resolution in Since the image input in this way is transmitted to the receiving side, image information can be input and transmitted at the resolution based on the resolution instruction from the receiving side, and the use and display size of the received image information on the receiving side. It is possible to realize efficient image transmission with the optimum resolution required according to the above.

Further, according to the image transmitting apparatus of the present invention, the resolution determining means for determining the spatial resolution of the image information based on the resolution control information notified from the destination apparatus of the image information, and the resolution determining means. An image information generating means for generating image information of the determined spatial resolution and an image information transmitting means for transmitting the image information generated by the image generating means to the destination device are provided, and the image information receiving side notifies it. Since the image information is generated and transmitted based on the resolution control information, the image information can be generated and transmitted at the resolution based on the resolution instruction from the receiving side, and the received image information on the receiving side can be obtained. It is possible to realize efficient image transmission with the optimum resolution required according to the application, display size, and the like.

Further, according to the resolution control device of the present invention, the spatial resolution of the image information transmitted to the destination device is controlled based on the resolution control information notified from the destination device of the image information. It is possible to control the resolution of the transmitted image information based on the resolution instruction from the receiving side of the image information, and select the optimum resolution required according to the use and display size of the receiving image information on the receiving side. be able to.

[Brief description of drawings]

FIG. 1 is a flowchart showing a resolution control operation of a transmission image according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an overall schematic configuration of a multimedia communication terminal according to a first exemplary embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining an example of a screen dividing and joining process according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining another example of the state of screen division and joining processing according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a resolution control operation of a transmission image according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing an overall schematic configuration of a multimedia communication terminal according to a second exemplary embodiment of the present invention.

FIG. 7 is a schematic diagram for explaining an example of a state of pixel shift and synthesis processing according to the second embodiment of the present invention.

FIG. 8 is a schematic diagram for explaining another example of the state of pixel shift and synthesis processing according to the second embodiment of the present invention.

[Explanation of symbols]

 202 document camera unit 203 split input control unit 204 screen joining unit 218 system control unit 219 resolution control information generation unit 220 received resolution control information recognition unit 221 resolution control unit 602 document camera unit 603 pixel shift input control unit 604 screen synthesis unit 618 system Control unit 619 Resolution control information generation unit 620 Reception resolution control information recognition unit 621 Resolution control unit

Claims (9)

[Claims] 1. An image transmission method for transmitting image information via a communication line, wherein image information of a spatial resolution indicated by resolution control information notified from a destination device of the image information is generated,
An image transmission method characterized in that the image is transmitted to the destination device. 2. The image transmission method according to claim 1, wherein the low resolution image information is transmitted prior to the transmission of the image information. 3. An image transmission method for transmitting input image information through a communication line, the receiving step of receiving control information indicating a spatial resolution of the transmitted image information from a destination device of the image information. A resolution determining step of determining a spatial resolution of the transmission image information based on the control information received in the receiving step; and an image input step of inputting image information of the spatial resolution determined in the resolution determining step. An image transmission method characterized by the above. 4. The image input step is for dividing an entire screen into a plurality of screens, inputting the images, and then joining the images to input image information having a higher resolution. A split input control step for selecting a split screen input method corresponding to the spatial resolution determined in the resolution determination step, and a split for inputting each split screen image according to the split screen input method selected in the split input control step 4. The image transmission method according to claim 3, comprising a screen input step and a joining step of joining the images of the split screens input in the split screen input step. 5. The image inputting step comprises inputting images of a plurality of screens by shifting pixels by a minute unit, and then inputting image information having a higher resolution by synthesizing the images. The image of each screen is input according to the pixel shift input control step of selecting the pixel shift input method corresponding to the spatial resolution determined in the resolution determination step and the pixel shift input method selected in the pixel shift input control step. 4. The image transmission method according to claim 3, further comprising: a pixel shift screen input step for performing the pixel shift screen input step; 6. The image input step comprises: a variable input step of inputting the image information at a variable resolution; a resolution conversion step of performing a resolution conversion process on the image information input in the variable input step; When performing the processing of the input step and the resolution conversion step, the resolution conversion for controlling the combination of the input resolution in the variable input step and the conversion resolution in the resolution conversion step according to the spatial resolution determined in the resolution determination step. The image transmission method according to claim 3, further comprising an allocating step. 7. An image transmission device for transmitting image information via a communication line, wherein a resolution determination for determining a spatial resolution of the image information based on resolution control information notified from a destination device of the image information. Means, image information generating means for generating image information of the spatial resolution determined by the resolution determining means, and image information transmitting means for transmitting the image information generated by the image generating means to the destination device. An image transmission device characterized by the above. 8. A resolution control device for controlling the resolution of image information transmitted via a communication line, which is transmitted to the destination device based on the resolution control information notified from the destination device of the image information. A resolution control device comprising a resolution control means for controlling a spatial resolution of image information. 9. The resolution control means receives the control information indicating the spatial resolution of the transmission image information from a destination device of the image information, and the resolution control means based on the control information received by the reception means. 9. The resolution control device according to claim 8, further comprising: a resolution determining unit that determines a spatial resolution of the image information; and a control unit that controls the spatial resolution of the image information according to the content determined by the resolution determining unit.