JP2010268065A - Color adjustment method, color adjustment device, video communication system, and color adjustment program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately and naturally display colors of images obtained from respective base points without congruity sense in a video communication system with a plurality of the base points. <P>SOLUTION: A color adjustment device 2 performs adjustments of video color information output from video output devices installed in an own base point S<SB>1</SB>which is possible to communicate with a plurality of other base points S<SB>2</SB>to S<SB>n</SB>. A color conversion data creation unit 24 in the color adjustment device 2 creates parameters for performing color conversion of a video output device in the own base point S<SB>1</SB>as color conversion databased on input and output characteristics of the video output device which is a color adjustment object in the own base point S<SB>1</SB>, and input and output characteristics of a master video output device determined from input and output characteristics of the video output devices in other base points S<SB>2</SB>to S<SB>n</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a video communication system including a plurality of bases having video input / output devices.

  The video conference system includes a codec device, a video input device such as a camera, a video output device, an audio device (microphone and speaker), and a multipoint connection device (MCU) (Non-Patent Document 1). The codec device encodes the captured video and audio and transmits them to the communication partner, and also decodes the encoded video and audio data sent from the communication partner for display on the video output device. And playback on speakers. The MCU performs communication control when communication is performed between three or more bases. When the MCU is placed in one of the bases that perform communication, or installed in the center, the MCU provides a function as a service. There is a case. The camera may be integrated with the codec device, but in a video conference system using a PC, the camera is separately prepared and installed. Also, a television or PC monitor is usually used as the video output device. Therefore, the video conference system does not manage the specifications of video input / output devices.

  Since the MCU has only a communication control function, it does not manage or adjust specifications related to display / photographing of devices connected to the video conference. Further, since the codec device does not know the characteristics of video input / output devices connected to other sites when encoding and decoding video, it is impossible to adjust the color between the sites.

  On the other hand, as a technique for color matching between video input / output devices, a method of performing color correction in accordance with a format defined by ICC (International Color Consortium) is known (Non-Patent Document 2). This is because a file (referred to as an ICC profile) describing the input / output characteristics of a video output device or video input device is created in advance, and the input and output colors are used using these profiles during video output. It is a mechanism to match.

  As shown in FIG. 5, the input / output characteristics are colorimetric values (XYZ tristimulus values, CIELAB, CIELAB, etc.) for the color spaces (RGB, CMYK, etc.) handled by the video input / output devices 51-54. The relationship between these two types of color spaces is described using a common space as a color space. In color matching using an ICC profile, color information handled by each of the devices 51 to 54 is converted through a common color space to perform device-independent color expression.

The input / output characteristics of the device will be briefly described below. FIG. 6 shows a configuration from when a scene including an object 60 under a certain illumination 61 is acquired as an image by the video input device 62 and output from the video output device 63. In general, in the case of the video input device 62, as shown in the characteristic diagram of FIG. 7A, the pixel value (RGB) obtained with respect to the input to the video input device 62, that is, the reflected light (physical quantity) from the object 60 Value) has a characteristic represented by an upwardly convex curve. Further, as shown in FIG. 7B, in the case of a video output device 63 such as a monitor, on the contrary, the relationship between the physical quantity (luminance) of the displayed color with respect to the pixel value is like a downwardly convex curve. It has special characteristics. Usually, such input / output characteristics are called γ characteristics, and are expressed as shown in Equation (1).
(Output) = α · (input) ^γ + β (1)
In the above equation, (input) corresponds to a physical quantity in the video input device 62 and a pixel value in the video output device 63, and (output) corresponds to a pixel value in the video input device 62 and a physical quantity in the video output device 63. Α and β are coefficients, and the input / output characteristics vary greatly depending on the index γ. An ICC profile describes the relationship between device-specific inputs and outputs as a profile, and is expressed as a function as shown in the above equation (1) or in a LUT (Look Up Table) format. There is also.

VTV Japan Co., Ltd., “Video conference / TV conference system MCU.info of multipoint connection device”, [online], February 2008, [March 30, 2009 search], Internet <URL: http: // www . h323. jp / index. html> The Color Society of Japan, “New Color Science Handbook”, 2nd edition, University of Tokyo Press, June 1998, pp. 1137-1151

  However, the above-described video communication system has the following problems.

  The conventional video communication system can perform multipoint communication connection control in the control function, but cannot perform control related to the specification of the equipment between points. The codec device encodes and decodes video, and transmits and receives encoded video data. However, it is not possible to consider the specifications and display environment of the device when determining the colors at the time of encoding and decoding. Absent. As mentioned above, color adjustment information for both video input devices and video output devices is required to adjust the color for the entire video input / output, and the color characteristics of the video input / output devices at other locations. In a conventional video communication system that does not have information, there is a problem that colors in video output devices such as monitors between different video communication bases are not correct.

  Further, the conventional color correction using the ICC profile has been aimed at displaying colors correctly between predetermined input / output devices for a local system as shown in FIG. 6 or a one-to-one system. . However, in a video communication system extending over a plurality of sites, it is assumed that images from a plurality of sites are simultaneously displayed on a monitor at one site.

In the example shown in FIG. 8, images from three locations (S _{1 to} S ₃ ) are displayed on one type of monitor 80, and images from each location (S _{1 to} S ₃ ) are input / output. Depending on the characteristics (ICC profile, etc.) of the device (monitor 80), the same color as that at the base is reproduced. Although the correct color is displayed for the video, if a video communication system such as a TV conference that spans multiple locations is assumed, a display that matches a certain environment is required when realizing the same room feeling or sharing materials. Need to do. In the conventional color correction, the uniform color matching between a plurality of sites is not considered as described above.

  As described above, in the conventional video communication system having a plurality of bases, the colors displayed on the video output device such as the monitor are different among the bases, and the displayed colors are inaccurate or unnatural. There was a problem.

  Therefore, the present invention outputs video based on the input / output characteristics of the video output devices at the local site and the other sites, or the input / output characteristics of the video input device, and the input / output characteristics of the master video output device determined from the color information of the illumination light. Parameters for performing device color conversion are generated as color conversion data.

  As an aspect of the color adjustment method of the present invention, there is provided a color adjustment method for adjusting color information of a video output from a video output device provided at a local site capable of communicating with a plurality of other sites, The color conversion data generation means of the master determined from the input / output characteristics of the video output device that is the color adjustment target at the local site and the input / output characteristics of the video output devices that are the target of color adjustment obtained from each other site There is a step of generating, as color conversion data, a parameter for performing color conversion of the video output device at the local site based on input / output characteristics of the video output device.

  As an aspect of the color adjustment apparatus of the present invention, there is provided a color adjustment apparatus that adjusts color information of a video output from a video output device provided at a local site capable of communicating with a plurality of other sites, Based on the input / output characteristics of the master video output equipment determined from the input / output characteristics of the video output equipment subject to color adjustment and the input / output characteristics of all the video output equipment subject to color adjustment obtained from other bases Color conversion data generation means for generating, as color conversion data, parameters for performing color conversion of the video output device.

  As an aspect of the video communication system of the present invention, video input by video input devices provided at a plurality of sites capable of communicating with each other or video output from video output devices is displayed on the video output devices at the respective sites. In the communication system, each site includes a color adjustment device that adjusts color information output from the video output device, and the color adjustment device has input / output characteristics of a video output device that is a color adjustment target in the local site. And parameters for color conversion of the video output device at the local site based on the input / output characteristics of the master video output device determined from the input / output properties of the video output devices subject to color adjustment obtained from each other site. Color conversion data generation means for generating color conversion data is provided.

  Note that the present invention can also be in the form of a program that causes a computer to function as color conversion data generation means according to the color adjustment apparatus.

  Therefore, according to the above invention, in the video communication system having a plurality of bases, the color of the video acquired from each base can be displayed accurately and naturally without any discomfort.

1 is a schematic configuration diagram of a color adjustment apparatus according to an embodiment of the invention and a video communication system having the same. 1 is a schematic configuration diagram of a media system according to an embodiment of the invention. 6 is a flowchart illustrating a process of generating color conversion data by the color adjustment apparatus according to the embodiment of the invention. (A) A flowchart explaining transmission of an input / output characteristic file of a video input / output device to another site by the site according to the embodiment of the invention, (b) color conversion data by the control unit of the color adjustment device according to the embodiment of the invention. The flowchart explaining control of production | generation, (c) The flowchart explaining operation | movement of the media system which concerns on embodiment of invention. 1 is a schematic diagram of a conventional color management system. An example of a video input / output system. (A) Characteristic diagram showing the relationship between reflected light (physical quantity) and pixel value (RGB value) in video input equipment, (b) Relation between pixel value (RGB value) and reflected light (physical quantity) in video output equipment FIG. Explanatory drawing of the technical subject of the conventional color matching system.

  Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to this embodiment.

The video communication system 1 according to the embodiment of the present invention is composed of a plurality of bases S _i (i = 1, 2, 3,..., N) that can communicate with each other via a network 4 as shown in FIG. The

The base S _i (i = 1, 2, 3,..., N) includes a color adjusting device 2 and a media system 3.

  As shown in FIG. 1, the color adjustment apparatus 2 includes a database 21, a control unit 22, a communication unit 23, and a color conversion data generation unit 24.

  As shown in FIG. 2, the media system 3 has the same configuration as a conventional video conference system or video phone system. The media system 3 includes a video input device 31, a video output device 32, and an audio device 33, a codec device 34 that processes media data to be transmitted and received, and a multipoint connection device (hereinafter referred to as connection device) 35 that performs communication control. Examples of the video input device 31 include a camera, a document camera, and a scanner. Examples of the video output device 32 include a monitor, a projector and a screen, and a printer.

The color adjusting device 2 at the base S ₁ communicates with other bases (for example, _Si (i = 2, 3,..., N)) via the network 4 so that the video input device and the video output device related to the other bases. Adjust the color.

When video communication is performed between a plurality of bases S ₁ , S ₂ , S ₃ ,... Constituting the entire video communication system 1, first, one of the individual bases (S ₁ , S ₂ , S ₃ ,. In the connection device 35 of the media system 3), an address necessary for each base to communicate with each other is obtained. Based on the information from the connection device 35, the color adjustment device 2 communicates data related to the input / output characteristics of the device with the ground, generates color conversion data, and transmits it to the media system 3. The media system 3 sets the color conversion data received from the color adjustment device 2 in the codec device 34 and starts video communication.

In the color adjusting apparatus 2, the database 21 stores the input / output characteristic file of the video input device 31 and the video output device 32 used in the media system 3 of the local site (for example, the site S ₁ ) and the color information file of the illumination light of the illumination 36. Storing. The management items of the database 21 are as follows, and are managed in correspondence with device identifiers such as model numbers.
(1) Input / output characteristics of video input device 31 (2) Input / output characteristics of video output device 32 (3) Color information of illumination light of illumination 36 Input / output characteristics of (1) and (2) Although it is often provided as an ICC profile from a manufacturer, it can also be measured and created using a commercially available tool. In addition, as the information of (3), data measured in advance by a colorimetric device or data provided from the manufacturer of the illumination 36 may be used.

The control unit 22 controls each component (functional means 21, 23, 24) of the color adjustment apparatus 2 to generate color conversion data to be provided to the media system 3 through steps S 1 to S 4 of the flowchart shown in FIG. Let it run. The control unit 22 is communicably connected to the codec device 34 and the connection device 35 of the media system 3 shown in FIG. 2 in the same base (for example, the base S ₁ ). Further, the control unit 22 can exchange data with other bases (bases S _{2 to} S _n ) in the video communication system 1 through the network 4 via the communication part 23.

Based on the connection destination information obtained from the connection device 35 of the media system 3, the communication unit 23 communicates with the color adjustment device 2 of the communication partner (for example, the bases S _{2 to} S _n ) designated by the control unit 22 to input the video. Transmits and receives input / output characteristics of output devices and color information of illumination light.

  The color conversion data generation unit 24 generates color conversion data for display according to the characteristics of the target video output device based on the input / output characteristics of each device.

Specifically, the color conversion data generation unit 24, the input-output characteristics of the video output device 32 of the input-output characteristics and the other base of the video output device 32 of the own base (e.g. S ₁₎ (e.g., S ₂ to S _n) Based on the input / output characteristics of the master video output device determined from the above, parameters for color conversion of the video output device 32 at the local site are generated as color conversion data ([Case 1] described later).

Further, the color conversion data generation unit 24 obtains the color information of the master illumination determined from the color information of the illumination 36 at its own site (for example, S ₁ ) and the color information of the illumination at the other sites (for example, S _{2 to} S _n ). This is used for calculation to generate parameters for color conversion of the video output device 32 at its own base ([Case 2] described later).

The color conversion data generation unit 24 obtains the own base (e.g. S ₁₎ or any of the input-output characteristics of the image input device 31 of the plurality of other locations (e.g., S ₂ to S _n), and this property Based on the input / output characteristics of the video output device 32 at the local site, parameters for color conversion of the video acquired by the video input device 31 output from the video output device 32 are generated as color conversion data (described later). [Case 3]).

Furthermore, the color conversion data generation unit 24, the site itself (e.g., S ₁₎ or the video by the input-output characteristic and the video input device 31 of one of the image input device 31 of the plurality of other locations (e.g., S ₂ to S _n) The information on the illumination light at the time of acquisition is acquired, and the information on the color of the illumination light after color conversion that is set in advance by an agreement between the local base or the plurality of other bases is acquired by the video input device. This is used for calculation to generate a parameter for performing color conversion of the acquired video ([Case 4] described later).

A process (S1 to S4) of generating color conversion data by the color adjusting apparatus 2 will be described with reference to FIG. Site S ₁ in the case being described below own base, the base S ₂ to S _n has a different hub. Here, it is assumed that the video input / output devices to be color-matched are determined in advance.

S1: The control unit 22 of the color adjusting apparatus 2 transmits the input-output characteristic file of the image input-output device 37 of the own base S ₁ (video input device 31, a video output device 32) to the other base S ₂ to S _n.

More specifically, according to the procedure (S101, S102) shown in FIG. 4A, input / output characteristics and color information are transmitted to the other bases S _{2 to} S _n that perform video communication.

In S101, the drawer video input and output devices 37 (video input device 31, a video output device 32) according from the database 21 to the media system 3 of own base S ₁ input-output characteristic file, the color information of the illumination light, the communication unit so 23 to each ground (other bases S _{2 to} S _n ) via the network 4.

In S102, the execution of step S101 is repeated until transmission to all the grounds (other bases S _{2 to} S _n ) is completed.

S2: The control unit 22 adjusts the display environment with other bases (S _{2 to} S _n ), and determines the display environment at its own base S ₁ . That is, in performing video communication between a plurality of sites (S _{1 to} S _n ), a master video input / output device (hereinafter referred to as a master) for matching the final display environment with other sites (S _{2 to} S _n ). Determined) with other bases.

A specific example of a method of determining the video output device M _{target as} a master and a method of acquiring the input / output characteristic P _Mtarget will be described. Here, a method for determining three types of master video output devices is shown as an example. Actually, it is assumed that the method for determining the master is determined in advance.

[Example 1] A standard video output device as a reference is set as a master, and its input / output characteristic file is stored in the database 21 in advance. The master may select the one closest to the standard input / output characteristic from among the video output apparatuses 32 between the bases (S _{1 to} S _n ), or the video output apparatus having the ideal input / output characteristic. May be assumed.

[Example 2] the video output device 32 of the organizer of the video communication (e.g. S ₁₎ and the master, organizers in the other base output characteristic of the video output device 32 of the own base S ₁ (S ₂ ~S _n) Send.

[Example 3] A video output device having the narrowest color reproduction range among the video output devices 32 of participating sites (S _{1 to} S _n ) is set as a master.

In this procedure, a case where the video output device 32 is a monitor will be described as an example. The input / output characteristics P _Mk of the monitor M _k at its own site (S ₁ ) and the contents of the input / output characteristics P _Mk of the monitor M _k at other sites (S _{2 to} S _n ) acquired at S 301 are analyzed, and The physical quantity corresponding to the value having the highest value is compared, and the input / output characteristics of the monitor having the smallest physical quantity are determined to have a narrow color reproduction range.

  For example, assuming that the pixel value of an image is a combination of three types of color components R (red), G (green), and B (blue), each represented by 8 bits, the highest pixel value The values are (255, 0, 0) for the R component, (0, 255, 0) for the G component, and (0, 0, 255) for the B component. For each target monitor, the physical quantity value when these three colors are output to the monitor is obtained using the input / output characteristic file, and the monitor with many color components having the smallest value has a narrow color reproduction range. Judge and make it the master monitor.

S3: The control unit 22 generates color conversion data when displaying the image of the ground (base S ₂ -S _n ) on the video input / output device 37 of its own base S ₁ by the procedure of S 301 -S 304 in FIG. Control processing.

  In step S301, input / output characteristics and illumination color information of the video input / output device 37 used in the corresponding video communication session are received for all ground systems that perform video communication via the communication unit 23.

In S302, it executes the following processing for the video output device 32 of each base (S ₁ to S _n) based on the input-output characteristic of the received ground (base S ₂ ~S _n).

Video output device 32 of the own base S ₁ stored in the database 21 and input-output characteristic of (e.g. a monitor), a monitor in the case of the video output device 32 (FIG. 2 of ground (base S ₂ to S _n) received in S301 Based on the input / output characteristics of the printer, projector, and screen), the color conversion data generating unit 24 generates color conversion data to be applied to the video output device 32 on the local site S ₁ side.

  The characteristics of the video input device 31 and the video output device 32 by the color conversion data generation unit 24 in S302 and the principle of color matching using these will be described with reference to FIG.

  In the configuration shown in FIG. 6, an example is shown in which an object 60 under the light of the illumination 61 is captured by a camera 62 (video input device) and displayed on a monitor 63 (video output device). In this case, it is assumed that the input / output characteristics (ICC profile and the like) of the camera 62 and the monitor 63 are obtained in advance. The input / output characteristics of the camera 62 can be expressed by a function f as follows, as a correspondence relationship between XYZ tristimulus values, which are physical quantities, and RGB values. Here, the function f is expressed by a combination of a 3 × 3 matrix and a γ coefficient, for example.

  On the other hand, the input / output characteristics (ICC profile, etc.) of the monitor 63 can also be expressed by a function g as follows, which is composed of a combination of a 3 × 3 matrix and a γ coefficient.

When an image captured by the camera 62 is expressed as a value in the RGB space, a physical quantity (here, XYZ tristimulus values) can be obtained using inverse transformation of the function f. Equation (4) shows this conversion. From the arbitrary pixel values (R _cam , G _cam , B _cam ) in the image, the information (X, Y, Z) of the scene before being captured by the camera 62 can be obtained from Expression (4).

  If the color displayed on the monitor 63, that is, the physical quantity, and the XYZ tristimulus values obtained by the above equation (4) match, the actual scene color matches the color displayed on the monitor 63. Become. Accordingly, the input / output characteristics of the monitor 63, that is, the inverse function of the function g below, is used as the result of the equation (4) to obtain the RGB value necessary for outputting a correct color.

As shown in equation (6), the conversion from (R _cam , G _cam , B _cam ) to (R _cam ′, G _cam ′, B _cam ′), that is, the inverse conversion of the combined function of functions f and g is performed. By doing so, color matching between the camera 62 and the monitor 63 is realized.

  In S303, the color conversion data generated in S302 is transmitted to the media system 3.

  In step S304, the steps S302 and S303 are repeatedly executed for all the remaining video output devices that are color matching targets.

  S4: The media system 3 receives the color conversion data from the color adjustment device 2 and adjusts the display of the video output device 32 in the procedure of S401 and S402 in FIG.

  In S401, the color conversion data is received from the color adjustment apparatus 2.

  In S402, when the color conversion data of each video output device (monitor, printer, projector, and screen) in the video output device 32 received from the color adjustment device 2 is set in the codec device 34, the codec device 34 corresponds. The output of the video output device 32 is adjusted based on the set color conversion data.

  The example of the color matching of the video display of the video output apparatus by the above video communication system 1 is shown.

The bases included in the image communication system 1 according to the case being described below S ₁ as illustrated in Figure 1, ..., which is of n S _n. Bases S _i video input device C _i under, _j, a video output device M _i, denoted by _j (where, j is for distinguishing a plurality of image input devices to a video output device in the same base These input / output characteristics are denoted by P _Ci , _j , P _Mi , and _j , respectively. In the following description, the input / output characteristics are expressed by a 3 × 3 matrix. Illumination light L _i under base S _i is assumed to be represented by a matrix of 3 × 1.

[Example 1: Monitor color matching between multiple locations]
In Case 1, for the same video displayed from monitors having different characteristics at a plurality of sites (S _{1 to} S _n ), the monitor color matching between sites is performed by using the input / output characteristics of the monitor according to the following process. Is realized. Assume that n locations S _i (i = 1, 2,..., n) include monitors M _i (i = 1, 2,..., n).

(Process 1) site S _1, S _2, ..., between the S _n, as described above monitor M _target (to master, M _target is to may be one or any of the M ₁ ~M _n , You can negotiate a virtual monitor).

(Process 2) Next, the base that does not have the monitor determined as the master acquires the input / output characteristic P _Mtarget of the monitor M _target from the base having the master monitor.

(Process 3) Subsequently, the monitor M monitors M of the display and the base in _{target k (k = 1,2, ...} , n) in order to adjust the display, the color adjustment device at each base (S ₁ to S _n) 2 acquires the input / output characteristic P _Mk of the monitor M _{k at} the local site from the database 21.
Where P _Mtarget = P _Mk · Q
Q is obtained, and this is obtained as color conversion data corresponding to M _k .

  Therefore, according to the case 1, the problem that the colors of the same scene displayed at different bases are different from each other is solved. In addition, the problem that colors do not match when images from a plurality of sites are displayed on the output devices in each site is solved.

[Case 2: Color matching of observed video output equipment]
In Case 2, in video communication over a plurality of locations, when the color of the illumination light at each location affects the monitor display on the ground, color matching between monitors is realized by the following process. At n locations S _i (i = 1, 2,..., n), the monitor M _i (i = 1, 2,..., n) under the illumination light L _i (i = 1, 2,..., n). Is connected.

(Process 1) site S _1, S _2, ..., between S _n, M _target so that the monitor M _target (described above to master to may be one or any of the M ₁ ~M _n, A virtual monitor may be used) and the master illumination light L _target is negotiated between the bases. Here, the illumination light L _target to master could for instance choose the most light source close to the sunlight in the illumination light L _i bases, such as averaging in the illumination light L _i bases, or, There is a method of deciding by majority vote. Furthermore, there are methods of setting the illumination light of the meeting organizer or using standard light (C light source or D ₆₅ light source) determined in advance.

(Process 2) Next, the base that does not have the monitor determined as the master acquires the input / output characteristic file of the monitor M _target and the color information L _target of the illumination light from the base having the master monitor.

(Process 3) In order to match the color reflected from the monitor M _target under the illumination light L _target , the color adjusting device 2 inputs and outputs the monitors M _k (k = 1, 2,..., N) at each site. The characteristic and the color information L _target of the illumination light are acquired from the database 21. here,
L _target · P _k = L _target · P _Mtarget · Q
Q is obtained and obtained as color conversion data corresponding to M _k (S302 of S3).

  Therefore, according to Case 2, when video from another base is displayed at the local base, the video at the local base does not differ from the video at the other base without any difference in the color of the illumination light from the local base. It is displayed naturally.

[Case 3: Camera-captured scenes are displayed correctly on monitors at other locations]
In Case 3, the video of a scene shot by a camera in a certain base can be displayed in a correct color on a monitor having different input / output characteristics in video communication through the following process.

Images taken by a camera C _k (k = 1, 2,..., N) at a certain site S _k (k = 1, 2,. ,..., N) will be described in the case of displaying correctly on the monitor M _i (i = 1, 2,..., N). In the following description, it is assumed that the camera C _k is connected to the K-th base S _k .

(Process 1) The base S _i (i = 1, 2,..., N) has an input / output characteristic P _Ck (k = 1) of the camera C _k (k = 1, 2,..., N). , 2, ..., n).

(Process 2) Next, each site S _i (k = 1, 2,..., N) acquires the input / output characteristics of its own monitor M _i (i = 1, 2,..., N) from the database 21. To do.
Where P _Mi , Q, P _Ck = I
Q is obtained, and this is obtained as color conversion data corresponding to the monitor M _k under the base S _k . Note that I represents an identity map.

[Case 4: Displaying scenes taken by the camera on a monitor at another site for easy viewing]
When video of a scene shot with a camera in a base is affected by illumination light at the time of shooting on a monitor with different input / output characteristics in video communication, the following process The image can be corrected and displayed.

At a certain base S _k (k = 1, 2,..., N), the camera C _k (k = 1, 2, n) under the illumination light L _k (k = 1, 2,..., N). , ..., each site an image taken by any) of _{n S i (i = 1,2,} ..., video output device M _{i (i} = 1,2 of n), ..., n) the standard light source L _std Processing for displaying as a lower scene will be described.

(Process 1) Each base S _i (i = 1, 2,..., N) has an input / output characteristic P _Ck (k = 1) of the camera C _k (k = 1, 2,..., N). , 2,..., N) and illumination light information L _k at the time of video acquisition.

(Process 2) Next, under the agreement of each site S _i (i = 1, 2,..., N), the color information L _std of the converted illumination light is set. L _std may be the color of a standard light source such as D ₆₅ or C light source, or may be set to a virtual white color.

(Process 3) Finally, each site S _i (i = 1, 2,..., N) acquires the input / output characteristics of its own monitor M _i (i = 1, 2,..., N) from the database 21. To do. here,
P _Mi · Q · (L _std / L _k ) · P _Ck = I
Q is obtained, and this is obtained as color conversion data corresponding to the video output device M _k under S _k . Here, (L _std / L _k ) is a ratio of the color components of illumination light for each element. Note that I represents an identity map.

  Therefore, according to Case 4, the problem that the color of an actual scene photographed by a camera under a certain base is different from the actual color when displayed at another base through communication is solved.

[Case 5: Color matching between multiple video output devices in your site]
In the above-mentioned cases 1 to 4, it is possible to cope with the case where there are a plurality of video output devices in the base S _i (i = 1, 2,..., N). If there are differences in capabilities, these should be taken into account. In the case of Case 5, if the color reproduction capability of the monitors in the same base is taken into consideration, the master is set to have a small color reproduction range in the local base, and the color characteristics of other monitors are matched. Good.

  These cases 1 to 5 are cases where the video output device is a monitor, but the present invention can also be applied to cases where the video output device is a printer or a screen.

As described above, according to the video communication system 1 having the color adjusting device 2 according to the present invention and the bases S _i (i = 1, 2, 3,..., N) provided with the same, in video communication between a plurality of bases. Thus, it becomes possible to easily perform precise adjustment with respect to the color when displaying an image from its own site. Therefore, it is possible to increase the continuity of images at a plurality of remote locations in multi-point video communication, and it is possible to increase the sense of presence in communication. This also makes it possible to simultaneously display the same color video on a plurality of display devices in a digital signage system linked in a network.

  The color adjusting apparatus 2 according to the present invention described above is a personal computer (PC), and is a normal computer hardware resource such as a CPU, a hard disk drive, a memory (RAM), a communication device, a display, a mouse / keyboard, and the like. It is good also as an aspect provided with the input / output apparatus. The database 21 relating to the color adjusting device 2 is stored in an updatable manner in the internal memory of the computer or the external memory of the hard disk drive. The communication unit 23 may be realized by the communication device.

  In addition, the present invention may be in the form of a program that causes a computer to function as the function units 21, 22, and 24 that constitute the color adjustment device 2. This program is stored in a known recording medium (for example, CD-ROM, DVD-ROM, CD-R, CD-RW, DVD-R, DVD-RW, MO, HDD, Blu-ray Disk (registered trademark), etc.) Or through a network.

DESCRIPTION OF SYMBOLS 1 ... Video communication system 2 ... Color adjustment apparatus 21 ... Database, 24 ... Color conversion data generation part (color conversion data generation means)
3 ... Media system 31 ... Video input device, 32 ... Video output device, 33 ... Audio device, 34 ... Codec device, 35 ... Connection device, 36 ... Lighting, 37 ... Video input / output device _Si (i = 1, 2, 3, ..., n) ... Base

Claims (10)

A color adjustment method for adjusting color information of a video output from a video output device provided at a local site capable of communicating with a plurality of other sites,
From the input / output characteristics of the video output device that is the color adjustment target at the local site and the input / output characteristics of the video output devices that are all the color adjustment targets obtained from the other bases A color adjustment method comprising: generating, as color conversion data, a parameter for performing color conversion of a video output device at a local site based on the input / output characteristics of the determined master video output device. Parameters for the color conversion data generating means to perform color conversion of the master lighting color information determined from the lighting color information of the local base and the lighting color information of the local base of the video output device of the local base The color adjustment method according to claim 1, further comprising a step of performing an operation for generating the color. The color conversion data generation means acquires the input / output characteristics of the video input device at either the local base or the plurality of other bases, and outputs the video based on the characteristics and the input / output characteristics of the video output device at the local base. The color adjustment method according to claim 1, further comprising a step of generating, as color conversion data, a parameter for performing color conversion of a video obtained by the video input device output from the device. The color conversion data generation means acquires information on input / output characteristics of the video input device at one's own base or the plurality of other bases and illumination light at the time of video acquisition by the video input device, and these information, In order to generate parameters for color conversion of video obtained by the video input device, and information on the color of illumination light after color conversion set in advance by an agreement between the local site or the plurality of other sites The color adjustment method according to claim 3, further comprising a step of performing the calculation of the following. A color adjustment device that adjusts color information of video output from a video output device provided at a local site capable of communicating with a plurality of other sites,
The input / output characteristics of the master video output device determined from the input / output characteristics of the video output device subject to color adjustment at the local site and the input / output properties of the video output devices targeted for color adjustment obtained from other bases. A color adjustment apparatus comprising color conversion data generation means for generating, as color conversion data, a parameter for performing color conversion of a video output device at its base. The color conversion data generation means is a parameter for performing color conversion of the master lighting color information determined from the lighting color information of the local site and the color information of the lighting of the other site, for the video output device of the local site. The color adjusting apparatus according to claim 5, wherein the color adjusting apparatus is used for an operation for generating the color. The color conversion data generation means acquires the input / output characteristics of the video input device at either the local base or the plurality of other bases, and outputs the video based on this characteristic and the input / output characteristics of the local video output device. 7. The color adjustment apparatus according to claim 5, wherein a parameter for performing color conversion of a video obtained by the video input device output from the device is generated as color conversion data. The color conversion data generation means acquires the input / output characteristics of the video input device at one's own base or the plurality of other bases and the illumination light information at the time of video acquisition by the video input device, and these information, In order to generate parameters for color conversion of video obtained by the video input device, and information on the color of illumination light after color conversion set in advance by an agreement between the local site or the plurality of other sites The color adjusting apparatus according to claim 7, wherein the color adjusting apparatus is used for the calculation of In a video communication system for displaying video input from video input devices provided at a plurality of bases capable of communicating with each other or video output from video output devices on the video output devices of the respective bases,
Each of the bases includes a color adjustment device that adjusts color information output from the video output device,
The color adjustment device is a master video output determined from the input / output characteristics of the video output device that is the color adjustment target at its own site and the input / output characteristics of all the video output devices that are the color adjustment targets obtained from other sites. A video communication system comprising color conversion data generating means for generating, as color conversion data, a parameter for performing color conversion of a video output device at a local site based on input / output characteristics of the device.   9. A color adjustment program for causing a computer to function as each means constituting the color adjustment apparatus according to claim 5.

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