JP3585903B2 - Communication method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication method for transmitting and receiving an image using a communication line as a transmission medium.
[0002]
[Prior art]
Conventionally, as a communication device using such a communication method, there is a videophone device as shown in FIG.
[0003]
1 is a line interface unit for connecting to a digital communication line, 23 is a data transmission unit, 3 is a telephone unit, 24 is a data processing control unit for processing image information and various control information, 25 is an operation unit, and 6 is a display unit. Memory, 7 a D / A converter, 8 a display unit for displaying an image in the display memory 6, 9 an imaging unit for taking an image, 10 an A / D converter, 11 an acquisition memory, 21 Is a digital communication line, and 22 is a line terminating device (hereinafter abbreviated as “DSU”).
[0004]
Next, the operation will be described. An image such as a person image captured by the imaging unit 9 is converted into a digital video signal by the A / D converter 10 and stored in the capture memory 11. The digital video signal stored in the capture memory 11 is subjected to image compression processing in the data processing control unit 24, converted into image data, and sent to the data transmission unit 23. The data transmission unit 23 converts the image data into serial data conforming to the transmission speed of the digital communication line, sends the serial data to the line interface unit 1, and sends it out to the partner terminal via the DSU 22 and the digital communication line 21.
[0005]
Assuming that the partner terminal is a videophone having the same configuration as the present apparatus, the partner terminal receives image data from the DSU 22 at the data transmission unit 23 via the line interface unit 1. The data transmission unit 23 extracts image data from the serial data and sends it to the data processing control unit 24. The data processing control unit 24 performs a decoding process on the image data and converts the image data into a digital video signal. This digital video signal is stored in the display memory 6, converted into an analog video signal by the D / A converter 7, and displayed on the display unit 8.
[0006]
[Problems to be solved by the invention]
However, in the above-mentioned conventional apparatus, first, a screen standard of an image transmitted between users is determined, and after starting image communication, a screen standard of an image being transmitted or a screen of an image being received by each user. The standard could not be changed arbitrarily.
[0007]
The present invention has been made in view of such a point, and an object of the present invention is not only to allow a user to arbitrarily change the screen standard of an image being transmitted to a partner user during image communication, but also to change the screen standard transmitted from the partner user. It is an object of the present invention to provide a communication method of a videophone device that can arbitrarily remotely control a screen standard of an incoming image.
[0008]
[Means for Solving the Problems]
A communication method according to the present invention is a communication method for transmitting a digital video signal between a plurality of devices, wherein receiving digital video compression information, and obtaining control information in the received digital video compression information, Reproducing the received digital video compression information in accordance with the control information, wherein the control information includes at least the changed horizontal and vertical pixels transmitted when the number of horizontal and vertical pixels of the screen is changed. and indicates the number, the step of obtaining the control information, and obtaining the control information control information Ru is transmitted by multiplexing the image data, transmitted Ru said control as the control information field which does not include the image data comprising the steps of obtaining information, a feature that you change the horizontal and vertical pixel number of the screen during the transmission of a digital video signal To.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a block diagram showing a circuit configuration of the videophone device of the present embodiment. The control information processing unit 12 is added to the conventional videophone device shown in FIG. 4, and a data transmission unit 23, a data processing control unit 24, The operation unit 25 is improved.
[0010]
Here, the control information processing unit 12 functions to issue an instruction to the data processing control unit 4 in accordance with the screen standard selection input input from the operation unit 5 or the control information received via the data transmission unit 2. It has a function of outputting control information to the data transmission unit 2 in accordance with the input screen standard selection input.
[0011]
The data transmission unit 2 functions to transmit the control information input from the control information processing unit 12 to the other user together with the image data, and output the control information transmitted from the other user to the control information processing unit 12.
[0012]
The operation of the device of the present invention will be described. An image such as a human image captured by the imaging unit 9 is converted into a digital video signal by the A / D converter 10 and stored in the capture memory 11. The digital video signal stored in the capture memory 11 is subjected to image compression processing in the data processing control unit 4 in accordance with an instruction from the control information processing unit 12, converted into image data, and sent to the data transmission unit 2.
[0013]
The data transmission unit 2 converts the image data or the control information of the screen standard into serial data conforming to the transmission speed of the digital communication line, sends the serial data to the line interface unit 1, and sends it to the other terminal via the DSU 22 and the digital communication line 21. .
[0014]
The partner terminal receives the image data from the DSU 22 at the data transmission unit 2 via the line interface unit 1. The data transmission unit 2 extracts image data from the serial data and sends it to the data processing unit 4. Similarly, it extracts control information of the screen standard and sends it to the control information processing unit 12. The control information processing unit 12 outputs control information of the screen standard to the data processing control unit 4.
[0015]
The data processing control unit 4 performs a decoding process on the image data according to the control information to convert the image data into a digital video signal. This digital video signal is stored in the display memory 6, converted into an analog video signal by the D / A converter 7, and displayed on the display unit 8.
[0016]
In one embodiment of the present invention, three types of screen standards for images to be transmitted are prepared. The number of pixels in the horizontal direction (hereinafter abbreviated as “H”) and the vertical direction (hereinafter abbreviated as “V”) of each screen standard is 512 (H) × 480 (V) pixels in the high resolution mode and 256 (H) in the standard mode. H) × 240 (V) pixels, and 128 (H) × 120 (V) pixels in the high-speed mode. The number of gradations is the same for all three modes, and the luminance signal and the color difference signal have 256 gradations.
[0017]
FIG. 2 shows a transmission format of the control information of the screen standard. The control information of the screen is coded in the control information field shown in FIG. 2 and sent to the partner device. FIG. 2A shows a case where only control information is transmitted, and FIG. 2B shows a case where it is transmitted together with image data.
[0018]
When a certain device user changes the screen standard of an image being transmitted, a switching signal is input to the control information processing unit 12 by pressing a button on the operation unit 5. The video signal to be transmitted is subjected to image compression conforming to the screen standard in the data processing control unit 4 in accordance with an instruction from the control information processing unit 12, converted into image data, and transmitted to the data transmission unit 2.
[0019]
The data transmission unit 2 multiplexes only control information as shown in FIG. 2A or control information of a screen standard with the image data being transmitted as shown in FIG. I do.
[0020]
On the other hand, when the user wants to change the screen standard of the image being received from the other user, a switching signal is input to the control information processing unit 12 by pressing a button on the operation unit 5, and FIG. The control information alone is multiplexed as shown in FIG. 2A, or the control information of the screen standard is multiplexed with the image data being transmitted as shown in FIG.
[0021]
The partner user device that has received the control information issues an instruction from the control information processing unit 12 to the data processing control unit 4 according to the control information. Image compression processing is performed according to the instruction, and the image data is converted into image data. The method of transmitting the image data is the same as the method of transmitting the image data to the above-mentioned partner user, and thus the description is omitted here.
[0022]
Next, the data transmission unit will be described. FIG. 3 shows a block diagram of the data transmission unit 2. Here, reference numeral 31 denotes a serial interface circuit (hereinafter referred to as "SI / F") for converting an information channel signal transmitted / received via a digital communication line into parallel data, or conversely, converting parallel data into an information channel signal. ). The SI / F 31 is supplied with a clock signal from the line interface unit 1.
[0023]
Reference numeral 32 denotes a CPU for controlling the entire data transmission unit. 34 is a random access memory (hereinafter abbreviated as "RAM"), and 35 is a read-only memory (hereinafter abbreviated as "ROM"). 36 is a parallel interface (hereinafter abbreviated as "PI / F") for exchanging data between the data processing control unit 4 and the CPU 32, and 33 is control information between the control information processing unit 12 and the CPU 32. (Hereinafter, abbreviated as "I / F").
[0024]
Data received from the videophone device as the partner terminal is received by the SI / F 31 from the line interface unit 1 and temporarily stored in the RAM 34 by the CPU 32. Among the data stored in the RAM 34, the image data is sent to the data control unit 4 via the PI / F 36, and the control information is sent to the data control unit 4 via the I / F 36.
[0025]
On the other hand, image data from the data processing control unit 4 is taken into the RAM 34 via the PI / F 36. The control information is taken into the RAM 34 from the control information processing unit 12 via the I / F 33. The image data and control information fetched into the RAM 34 are multiplexed, converted into an information channel signal via the SI / F 31, sent to the line interface unit 1, and transmitted to a videophone device as a partner terminal.
[0026]
In this way, by transmitting and receiving control information of the screen standard of the image between the users during the image communication, not only the user can arbitrarily change the screen standard of the image being transmitted to the other user during the image communication, It is possible to provide a communication method capable of arbitrarily changing the screen standard of an image sent from a partner user.
[0027]
【The invention's effect】
Since the communication method of the present invention is configured as described above, the user can arbitrarily change the number of screen pixels of an image to be transmitted to the other party during image communication according to the type of the image to be transmitted, the other party's device, and the like. .
[0028]
In addition, the transmission side and the reception side can capture the number of screen pixels of the image transmitted to each other, and after exchanging control information, there is no need to transmit data. , The data can be transmitted without waiting for the response of the receiving side in the control of the broadcast, which is one-to-many transmission.
[0029]
Furthermore, since control information is added only to positions where the number of screen pixels changes in a continuous moving image, an increase in the total transmission amount is prevented, and the number of pixels is changed on the receiving side from the immediately preceding frame. The decoding process can be performed without determining whether or not the decoding has been performed, and the processing load at the time of decoding can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a circuit configuration of a videophone device according to one embodiment of the present invention.
FIG. 2 is an explanatory diagram of a transmission format of a control signal in one embodiment of the present invention.
FIG. 3 is a block diagram illustrating a circuit configuration of a data transmission unit according to one embodiment of the present invention.
FIG. 4 is a diagram showing a circuit configuration of a conventional videophone device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Line interface part 2 Data transmission part 3 Telephone part 4 Data processing control part 5 Operation part 21 Digital communication line 22 DSU

Claims (1)

In a communication method for transmitting a digital video signal between a plurality of devices,
Receiving digital video compression information;
Obtaining control information in the received digital video compression information;
Reproducing digital video compression information being received in accordance with the control information,
The control information is transmitted when at least the number of horizontal and vertical pixels of the screen is changed, and indicates the changed number of horizontal and vertical pixels.
Obtaining the control information, and obtaining the control information control information Ru is transmitted by multiplexing the image data, and obtaining the control information that will be transmitted as the control information field which does not include image data, the comprising, a communication method characterized that you change the horizontal and vertical pixel number of the screen during the transmission of digital video signals.

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