JPH11234639A - Videophone equipment - Google Patents

Abstract

(57) Abstract: A videophone device of a standard that converts image data captured by an NTSC camera into CIF data and transmits / receives the data, so that characters and / or graphics can be transmitted without reducing transmission efficiency. To SOLUTION: Image data from an NTSC camera 101 and a character / graphic input unit 10 such as a handwriting tablet are provided.
2 converts the character / graphic data from the format conversion unit 103
, The data is combined with data of one screen. The converted image data is referred to as H.264. 261 / H. The H.263 encoding unit 104 encodes the data and transmits it to the destination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a videophone device capable of transmitting and displaying information such as input characters and figures in addition to an image photographed by a camera such as an NTSC system to a partner device. About.

[0002]

2. Description of the Related Art In recent years, videophones capable of transmitting moving images have been put into practical use due to the development of information compression technology and the development of digital communication networks.

[0003] As this standard, ITU-T Recommendation H. 26
1 or H. 263, which is based on NTSC or PA
Image coding for audio / visual communication that specifies coding for converting image data of video signals obtained by shooting with a camera such as the L system into a common intermediate format called CIF (Common Intermediate Form) and compressing information It is a method.

[0004] The common intermediate format CIF is defined as an image of 352 pixels x 288 lines in the horizontal and vertical directions, and is a non-interlace system of 29.97 images per second. For example, when transmitting image data with an NTSC camera,
From the 4: 2: 2 digital component data, a vertical digital interpolation filter is used to interpolate 240 vertical lines to 288 lines, and to perform frame dropping in the time direction to obtain about 30 CIF image data per second. Form.

[0005] The image data converted into such an image format is encoded by compression encoding processes such as predictive encoding, motion compensation, discrete cosine transform (DCT), and quantization.

The above standard also defines a QCIF having an image size of 1/4 of the CIF, and the image size of the QCIF is 176 pixels by 144 lines. This is also a 29.97-sheet non-interlace system per second.

[0007]

However, in the above-mentioned conventional videophone apparatus, if character and graphic information is additionally transmitted and received, the transmission data becomes larger in addition to the interpolated image data, and the transmission efficiency becomes higher. Is reduced.

Accordingly, the present invention provides a videophone device capable of transmitting and receiving character and graphic information without reducing transmission efficiency.

[0009]

In order to solve the above-mentioned problems, a videophone device according to the present invention is arranged so that image data of a video signal for one screen obtained by photographing with a camera is applied in the vertical direction of the screen. In a videophone device standardized to transmit image data by interpolation, an input means for inputting characters and graphics is provided, and image data for one screen from the camera is defined in the standard. Interpolation of the obtained image data is not performed, and at this time, the binary data output from the input means is synthesized and transmitted to an area where no image data exists at the lower portion of the screen. .

When the receiving side detects that no character or graphic information is present in the binary data portion, the received image data is vertically interpolated and displayed on a monitor. Features.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a videophone device according to the present invention.

On the transmitting side, the video telephone apparatus 100 includes image data 121 of a subject photographed by an NTSC camera 101 and character / graphic data 122 input by a character / graphic input unit 102 such as a handwritten tablet. Are combined in the format conversion unit 103 and converted into a predetermined data format. The converted data 123 is
H. 261 / H. The H.263 encoding unit 104 encodes the data and transmits it to the destination. On the receiving side, the display switching unit 105
After the received data is decoded, the screen is selectively switched between a screen in which an image and characters / graphics are combined or a screen only of an image of a subject, and outputs the screen to the monitor 106.

Here, the character / figure input unit 102 has a
It is an input device with a resolution of 52 pixels x 48 lines,
Assume that binary data is output.

The format conversion unit 103 includes the camera 10
The image data 121 input from I.T. 261 or H.264. 263 based on common intermediate format CIF data. At this time, interpolation is not performed to increase the number of lines in the vertical direction as in the related art, but is converted into CIF data of 352 pixels × 240 lines.
Then, instead of data interpolation, the character / graphic input unit 10
The binary data 122 obtained from 2 is synthesized.

More specifically, the format conversion unit 103
As shown in FIG. 2, it comprises a CIF converter 201 and a memory 202 connected to the output of the camera 101 of the NTSC system. The memory 202 has a storage area for storing CIF data and binary data, and stores the synthesized data 123 in the storage area.

As shown in FIG. 3, the synthesizing method is such that the image data converted into 352 pixels × 240 lines by the CIF conversion unit 201 is located at the upper part of the screen of 352 pixels × 288 lines in the horizontal direction. To store. The horizontal and vertical 352 output from the character / graphic input unit 102
Binary data of pixels × 48 lines is stored in the memory 202 so as to be located at the lower part of the screen and constitute one screen.

Returning to FIG. 261 / H. The H.263 encoding unit 104 encodes the input combined data according to ITU-T Recommendation H.264. 261 or H.264. It is an encoder conforming to H.263 and transmits to the destination.

Then, the display switching unit 105 on the receiving side
After decoding the received combined data, a screen is displayed on the monitor 106 according to the procedure shown in the flowchart of FIG. That is, when binary data of characters / graphics exists in the composite data, the screen display shown in FIG. 3 is performed. However, if no characters or graphics have been input, no information is displayed in the lower 48 lines of the screen. Therefore, if no character or graphic is input, the image data portion of 352 pixels × 240 lines is vertically complemented into image data of 352 pixels × 288 lines as shown in FIG. Switch to display.

[0019]

As described above, according to the present invention, when it is desired to send a simple character or figure, the character and the figure are transmitted to the other party together with the image taken by the camera, and are combined on one screen with the image of the speaker. The displayed characters / graphics can be displayed. At this time, instead of interpolating the image data in the vertical direction, binary data of characters and graphics is sent, so that the transmission efficiency does not decrease.
If there is no character or graphic information, a conventional conversation can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a videophone device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a format conversion unit of the apparatus.

FIG. 3 is an explanatory diagram of composite CIF data of an image and characters / graphics of the apparatus.

FIG. 4 is a flowchart showing the operation of a display switching unit of the apparatus.

FIG. 5 is an explanatory diagram for displaying only the entire screen by interpolating only image data.

[Explanation of symbols]

 101 camera 102 character / graphic input unit 103 format conversion unit 104 H. 261 / H. 263 encoding unit 105 display switching unit 106 monitor 121 image data 122 binary data 123 synthesized CIF data 124 decoded data 125 image data 201 CIF conversion unit 202 memory

Claims (2)

[Claims] 1. A videophone device which is standardized to interpolate image data of a video signal for one screen obtained by photographing with a camera and to transmit the image data in a vertical direction of the screen, Input means for inputting characters and graphics, so as not to interpolate the image data defined in the standard with respect to one screen of image data from the camera, A videophone apparatus wherein binary data output from the input means is combined and transmitted to an area where no data exists. 2. When the receiving side detects that there is no character or graphic information in the binary data portion, the received image data is vertically interpolated and displayed on a monitor. The video telephone device according to claim 1, wherein: