JPH0833000A - Method and device for video transmission - Google Patents

Abstract

PURPOSE:To keep picture quality as high as possible with respect to luminance information at the time of reducing the generated code volume by efficiently encoding and transmitting a video signal in accordance with a need for color information in the video transmission device used for a video conference or the like. CONSTITUTION:A video transmission device 1 consists of a color information generation part 4, a color information switching part 5, and an encoding and transmission part 6. The color information switching part 5 switches color information from an input video signal and that from the color information generation part 4, and selected color information is encoded and transmitted together with luminance information by the encoding and transmission part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video transmission device and method used in a video conference system or the like.

[0002]

2. Description of the Related Art A conventional video transmission device used in a video conference system is described in, for example, ITU-T Recommendation H.264.
There is a video transmission device conforming to 261. In this, the input video signal is encoded and transmitted as an information source consisting of luminance information and color information.

[0003]

However, in the above-mentioned conventional video transmission apparatus, even when the color information is not important, the ratio of the samples of the color information and the luminance information is transmitted with a constant value.

Therefore, even when the image quality of the video signal is changed in response to the change in the capacity of the transmission line, the luminance information is the same as the color information because the color information and the luminance information are coded by the same method. When the color information is reduced, the luminance information is also reduced. In addition, even in the case of a video signal of a single-colored subject, the temporal and spatial fluctuations of the color information, such as the flicker of the color information, occur due to environmental changes and noise, and the coding efficiency decreases.

The present invention was devised in view of the above circumstances, and an object thereof is to make it possible to increase the coding efficiency depending on the necessity of color information or the situation of an input video signal. And It is also intended to maintain the image quality of the luminance information as much as possible when reducing the generated code amount. Furthermore, it is intended to improve the efficiency of encoding / transmission and notify the receiving side of a caution for a specific area.

[0006]

According to a first aspect of the present invention, there is provided a video transmission device including: a color information generating section for generating color information;
A color information switching unit that selects either the color information output from the color information generation unit or the color information of the input video signal, the luminance information of the input video signal, and the color information output from the color information switching unit. An encoding / transmitting unit for encoding and transmitting is provided.

According to a second aspect of the present invention, there is provided a video transmission device,
In the video transmission device according to the first aspect, when the generated code amount of the video signal coding is reduced, the color information from the color information generation unit is selected as the color information to be coded.

A video transmission device according to a third aspect of the present invention is
A color information generation unit that generates color information, a color information switching unit that selects one of the color information output from the color information generation unit and the color information of the input video signal, the luminance information of the input video signal, and the color. An encoding / transmission unit that encodes and transmits the color information output from the information switching unit, and a single color determination unit that controls the color information generation unit and the color information switching unit based on the statistical properties of the input video signal. It is characterized by having.

A video transmission device according to a fourth aspect of the present invention is
A color information generation unit that generates color information, a color information switching unit that selects one of the color information output from the color information generation unit and the color information of the input video signal, the luminance information of the input video signal, and the color. An encoding / transmission unit that encodes and transmits the color information output from the information switching unit, an area control unit that controls the color information generation unit, the color information switching unit, and the encoding / transmission unit for an arbitrary area. It is characterized by having.

A video transmission device according to a fifth aspect of the present invention is
In the video transmission device according to the fourth aspect, the generated code amount is allocated to the area using the color information of the color information generating unit to be smaller than that to the area not using the color information.

According to a sixth aspect of the present invention, there is provided a video transmission device,
In the video transmission device according to claim 4 or 5,
A speaker discrimination unit is added, and the color information from the color information generation unit is encoded except for the speaker area.

A video transmission method according to a seventh aspect of the present invention is
In the video transmission method of notifying the speaker, the color information is added only to the speaker, and the other area is encoded as a monochromatic image.

A video transmission method according to claim 8 of the present invention is
In the video transmission method that notifies the speaker, color information is added only to the speaker, the other areas are made into monochromatic images, and a large amount of generated code is allocated to the speaker area for encoding / coding.
It is characterized by performing transmission.

[0014]

In the video transmission device according to the first and second aspects, the color information to be encoded can be switched according to the necessity of the color information, so that the overall encoding efficiency is improved. When color information is not required, it is possible to generate color information of a single color in the color information generation unit and encode the color information instead of the color information of the input video signal.
It is possible to allocate a large amount of generated code to the luminance information. Alternatively, when it is necessary to reduce the code generation amount, the color information can be preferentially reduced, so that it is possible to minimize the deterioration of the image quality related to the luminance information.

According to another aspect of the video transmission device of the present invention, the control is performed based on the statistical property of the color information of the input video signal.
It becomes possible to encode a video signal having almost monochromatic color information as a complete monochromatic video signal, and fluctuations in color information over time in the space of the input video signal itself, noise due to color information separation, etc. It becomes possible to remove, and highly efficient coding becomes possible.

In the video transmission device according to the present invention, a circuit capable of controlling color information for an arbitrary area is provided to notify the receiving side of a caution for the specific area. And, it is possible to improve the efficiency of encoding at the same time. This is because the color information of the input video signal can be assigned only to the attention area, or the color information output by the color information generating unit can be assigned. Especially when the speaker discrimination unit is combined, the speaker can be notified.

According to the video transmission method of claims 7 and 8,
A speaker can be seen at a glance, and at the same time, many generated codes can be assigned to the area of the speaker who is attracting attention, and highly efficient coding is possible.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A video transmission apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing the arrangement of a video transmission apparatus according to the first embodiment of the present invention. In FIG. 1, 1 is a video transmission device, 2 is a camera device for photographing a speaker of a conference, etc., 3 is a Y / C separation unit for dividing an input video signal into luminance information and color information, and 4 is a fixed (monochromatic) color. A color information generating section 5 for generating information, 5 is a color information switching section for switching the color information of the input video signal and the color information output by the color information generating section 4, and 6 is coding, multiplexing and transmission of luminance information and color information. An encoding / transmission unit 7 for controlling the color information, a control unit 7 for switching color information and controlling the generated code amount, and a transmission line 8.

Next, the operation will be described. The video signal captured by the camera device 2 is input to the Y / C separation unit 3 and separated into luminance information and color information. These video signals are encoded by the encoding / transmission unit 6. At this time, regarding the color information of the encoded video signal, the color information of the input video signal output from the Y / C separation unit 3 and the color information selected and fixed by the color information generation unit 4 ( Any one of the single colors) is selected by the color information switching unit 5. When the color information from the Y / C separation unit 3 is selected, the color information itself of the input video signal is input to the encoding / transmission unit 6, and when the color information from the color information generation unit 4 is selected, that color is selected. Information (monochromatic) is input to the encoding / transmission unit 6. The color information generating unit 4 is a single color (not only black and white, but also one of various colors
Color information is generated. Therefore, in the former selection, it is encoded as a colored image, and in the latter selection, it is encoded as a monochromatic image. Luminance information and color information are encoded / multiplexed in the encoding / transmission unit 6 and decoded on the receiving side through the transmission line 8.

Normally, the video transmission apparatus 1 transmits a colored video signal. However, there is a request from the user of the station or the game, or there is a report that the terminal of the game can display only a single color. In such a case, the control section 7 instructs the color information switching section 5 to select the color information from the color information generating section 4.

Further, if for some reason (for example, when the number of lines is reduced or a part of the transmission line capacity is used for another purpose), it is necessary to limit the amount of code generated by the video signal, the control is performed. The unit 7 issues an instruction to switch the color information to monochromatic information, controls the amount of generated codes of the encoding / transmission unit 6, and allocates more generated codes to the luminance information.

As described above, according to the present embodiment, when the color information is not necessary, more generated codes can be assigned to the luminance information, which enables highly efficient coding. Further, when it becomes necessary to reduce the amount of generated code, it is possible to preferentially reduce the color information, and thus it is possible to minimize deterioration of the image quality of the luminance information.

(Second Embodiment) FIG. 2 is a block diagram showing the arrangement of a video transmission apparatus according to the second embodiment of the present invention. In FIG. 2, as in the first embodiment, 1 is a video transmission device, 2 is a camera device for photographing a speaker of a conference, etc., 3 is a Y / C separation unit for dividing an input video signal into luminance information and color information, Reference numeral 4 is a color information generating section for generating fixed (single color) color information, 5 is a color information switching section for switching between the color information of the input video signal and the color information output by the color information generating section 4, and 6 is luminance information and color. An encoding / transmission unit for encoding, multiplexing, and transmitting information, 8 is a transmission path, and 9 is color information based on the statistical properties of input video signals (how much color variation occurs in a certain area). It is a single color determination unit that controls the switching unit 5 and the color information generation unit 4.

Next, the operation will be described. The video signal captured by the camera device 2 is input to the Y / C separation unit 3 and separated into luminance information and color information. These video signals are encoded by the encoding / transmission unit 6 and transmitted to the receiving side through the transmission line 8. Further, these video signals are also input to the monochromatic determination unit 9 and, based on the statistical properties thereof, a representative color is selected and whether or not to use the representative color is determined. When it is determined that the representative color is encoded and transmitted, the color information switching unit 5 is instructed to select the color information of the color information generation unit 4, and the color information generation unit 4 should be generated. Specify color information. When it is determined that the representative color is not transmitted, the color information switching unit 5 is instructed to select the color information of the input video signal.

As described above, according to this embodiment, when encoding and transmitting a video signal of a subject close to a single color, a single color is selected and fixed (representative color), so that fluctuations in color information can be suppressed. The quality of the transmitted video signal is further improved, and highly efficient transmission becomes possible.

In the above, the representative color does not have to be a color obtained from the characteristic (statistical characteristic) peculiar to the input video signal, and if it is a single color, it may be a fixed color regardless of the input video signal. . In addition, although the operation is performed in frame units in the present embodiment, the selection of color information and the generated color information of the color information generation unit 4 change in a specific area unit (for example, a 1/4 area of a frame). It doesn't matter.

(Third Embodiment) FIG. 3 is a block diagram showing the arrangement of a video transmission apparatus according to the third embodiment of the present invention. In FIG. 3, as in the first embodiment, 1 is a video transmission device and 2A.
2D is a camera device for photographing a speaker of a conference, 4 is a color information generating unit for generating fixed (monochromatic) color information, 5 is color information of an input video signal, and color information is output by the color information generating unit 4. A color information switching unit for switching between and, 6 is an encoding / transmission unit for encoding, multiplexing, and transmitting luminance information and color information, 8 is a transmission path, and 10 is a video signal input from a plurality of camera devices 2A to 2D. An image synthesizing unit for synthesizing and outputting luminance information and color information separately, 11 a speaker determining unit for determining a speaker among speakers, 12 a color information generating unit 4 and a color information switching unit 5. The area control unit controls the encoding / transmission unit 6.

Next, the operation will be described. Camera device 2A-
The video signal obtained by 2D shooting is input to the image synthesizing unit 10, and the images are synthesized and the luminance information / color information is separated. These video signals are encoded by the encoding / transmission unit 6 and transmitted to the receiving side through the transmission line 8. Further, according to the output of the speaker discrimination unit 11, the region control unit 12 monochromaticizes the region of the non-speaker so that the speaker can be recognized.

FIG. 4 shows an image at each part when it is assumed that the speaker A is making a statement. The shaded area is the area where the color information is changed, and the non-hatched area is the single color information. The value (monochromatic) indicates a region in which only the luminance information changes.
Here, FIG. 4A shows an example of the video signal output from the image synthesizing unit 10, and FIG. 4B shows an input image to the encoding / transmitting unit 6.

Under the control of the speaker discrimination unit 11, the region control unit 12 selects the color information output from the image synthesizing unit 10 in the speaker region, and controls the color information generation unit 4 in the other regions. In addition to selecting an appropriate single color, the color information switching unit 5 selects the color information from the color information generating unit 4.
Control. Further, the encoding / transmission unit 6 is controlled so that a larger code amount is assigned to the speaker area.

As described above, according to this embodiment, a speaker can be recognized at a glance, and at the same time, a large number of generated codes can be assigned to the area of the speaker who is attracting attention, which enables highly efficient coding. Become.

In this embodiment, one composite image is generated from four camera devices corresponding to the speaker and only the area of the speaker is colored. It is also possible to extract a speaker area from a video signal of a person captured, colorize only the area of the speaker among those areas, and transmit the colored area. Further, in this embodiment, the input video signal is from the camera device and is the video signal of its own station, but instead of this, video signals transmitted from a plurality of other stations are decoded and combined to switch the color information. Encoding
It is also possible to take the form of transmitting. Although the color information of the input signal is assigned to the point of interest in this embodiment, it is possible to assign the color information of the color information generator 4 to the point of interest.

[0034]

As described above, according to the present invention, when the color information is not necessary, more generated codes can be assigned to the luminance information, which enables highly efficient coding. Also, when it is necessary to reduce the generated code amount, it is possible to preferentially reduce the color information,
With respect to the brightness information, it is possible to minimize deterioration of image quality.

Further, when encoding / transmitting a video signal of an object having a color close to that of a single color, fluctuations in color information are suppressed, so that the image quality of the transmitted video signal can be made higher, or highly efficient. Transmission becomes possible.

Further, the speaker can be recognized at a glance, and at the same time, many generated codes can be assigned to the area of the speaker who is attracting attention, which enables highly efficient coding.

[Brief description of drawings]

FIG. 1 is a block diagram of a video transmission device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a video transmission device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a video transmission device according to a third embodiment of the present invention.

4A and 4B are diagrams of an output image of the image combining unit and an input image of the encoding / transmission unit in FIG.

[Explanation of symbols]

 1 ... Video transmission device 2 ... Camera device 3 ... Y / C separation unit 4 ... Color information generation unit 5 ... Color information switching unit 6 ... Encoding / transmission unit 7 ... Control unit 8 ... Transmission Path 9: Monochromatic determination unit 10: Image synthesis unit 11: Speaker determination unit 12: Area control unit

Claims (8)

[Claims] 1. A color information generating section for generating color information, a color information switching section for selecting one of color information output from the color information generating section and color information of an input video signal, and an input video signal A video transmission device comprising: an encoding / transmission unit that encodes and transmits luminance information and color information output from the color information switching unit. 2. The video transmission device according to claim 1, wherein color information from a color information generation unit is selected as color information to be coded when the generated code amount of video signal coding is reduced. . 3. A color information generating section for generating color information, a color information switching section for selecting one of color information output from the color information generating section and color information of an input video signal, and an input video signal An encoding / transmission unit that encodes and transmits luminance information and color information output from the color information switching unit, and controls the color information generation unit and the color information switching unit based on the statistical properties of the input video signal. A video transmission device comprising a single color determination unit. 4. A color information generating section for generating color information, a color information switching section for selecting one of color information output from the color information generating section and color information of an input video signal, and an input video signal An encoding / transmission unit that encodes and transmits luminance information and color information output from the color information switching unit, and controls the color information generation unit, the color information switching unit, and the encoding / transmission unit for an arbitrary area. A video transmission device, comprising: a region control section for performing. 5. The video transmission device according to claim 4, wherein the generated code amount is allocated to the area using the color information of the color information generating unit less than that to the area not using the color information. 6. The video transmission apparatus according to claim 4, wherein a speaker discrimination unit is added, and the color information from the color information generation unit is encoded except for the speaker area. 7. A video transmission method for notifying a speaker, wherein color information is added only to the speaker, and the other area is encoded as a monochromatic image. 8. A video transmission method for notifying a speaker, wherein color information is added only to the speaker, and an area other than that is a monochromatic image, and a large amount of generated code is allocated to the speaker area for encoding / transmission. A video transmission method comprising: