JP2008141698A - Chroma key device and video composition device - Google Patents

Abstract

To specify a range where a color desired to be a background color is displayed from a foreground image displayed on a screen, and immediately confirm a range specification result from an actual synthesized image.
A foreground video is supplied, and a key processing unit for generating a key signal indicating a synthesis ratio of the foreground video and the background video, a control unit, and an image memory for writing the foreground video are provided. . The control unit 2 samples pixel data in the specified range from the foreground video written in the image memory 3 based on information from the outside indicating the specified range on the screen, and determines the color based on the sampling result. A background color value in space is obtained, and information indicating the obtained background color value is sent to the key processing means 1. The key processing means 1 generates a key signal by comparing the data of each pixel of the foreground video with the background color value.
[Selection] Figure 3

Description

  The present invention relates to a chroma key device that generates a key signal for replacing the color of a portion of a foreground image whose range is designated on a screen with another background image as a background color, and a video composition device having such a chroma key function.

  In the field of video content production, two video signals are generally synthesized using a chroma key device. The chroma key device is a key for replacing a specific background color portion of one video signal (foreground video) with another video signal (background video) using the difference in hue in the color components of the color video signal. A signal is generated.

  The background color in the foreground image may be preset (for example, when a person is photographed against a blue or green screen and the screen color is set as the background color), In some cases, an arbitrary background color can be designated on a background color designation screen (see, for example, Patent Document 1).

  The background color designation screen described in Patent Document 1 is a screen in a color space in which the values of chroma signals Cr and Cb are taken on the horizontal axis and the vertical axis, respectively. Therefore, by specifying the background color on this screen, the value of the background color in the color space is immediately confirmed, so by comparing the data of each pixel of the video signal of the foreground video with the value of this background color, A key signal indicating a composition ratio of the foreground video and the background video is generated.

  However, the foreground video itself actually displayed on the screen is also used as the background color designation screen. As illustrated in FIG. 1, a frame-like cursor 71 whose position and size can be adjusted is displayed on the screen on which the foreground image 70 is displayed. The displayed portion is surrounded by the cursor 71. In this case, the chroma key device determines which color is designated as the background color based on the result of sampling the data of each pixel in the range designated by the cursor 71 in the video signal of the foreground video 70 (on the color space). It is necessary to determine the background color value).

  FIG. 2 shows an example of a conventional configuration of a chroma key device for generating a key signal for replacing the color of the portion of the foreground video whose range is specified by the cursor of FIG. 1 as another background video. A video signal as a foreground video is supplied to the key processing circuit 80. The key processing circuit 80 is a hardware circuit that generates a key signal from the foreground video and outputs the generated key signal together with the foreground video.

  Further, range designation information indicating the range designated by the cursor of FIG. 1 in the foreground video displayed on the screen is supplied from an external operation panel or the like (not shown) to the CPU 81 that controls the entire chroma key device. Based on this information, the CPU 81 sends a command for instructing sampling of pixel data in the range designated by the cursor to the key processing circuit 80 via the control signal line.

  The key processing circuit 80 samples the pixel data in the range instructed by the CPU 81 from the waveform of the foreground video signal passing through the inside by extracting one pixel at a time during several field periods. Then, for example, by averaging each sampled data, an operation for obtaining the value of the background color in the color space is performed. Then, by comparing the data of each pixel of the video signal of the foreground video with the value of the background color, a key signal indicating the synthesis ratio of the foreground video and the background video is generated.

  By supplying the key signal, the foreground video, and the video signal as the background video to a synthesis circuit (not shown), the background video of the foreground video is synthesized by the synthesis circuit.

JP-A-10-285611 (paragraphs 0360 to 0364, FIG. 45)

  By the way, in the chroma key apparatus having the configuration shown in FIG. 2, as described above, the key processing circuit 80 extracts one pixel at a time in several field periods from the waveform of the video signal of the foreground video passing through the inside. Since sampling is performed, it takes several seconds until sampling of all the pixel data inside the cursor as shown in FIG. The background color value calculation process and the key signal generation process after the sampling process are performed in real time (within a period of several fields), but the key signal is generated as a result of the time required for the sampling process. Is a few seconds after the range is specified with the cursor.

  For this reason, the operator must wait for several seconds before the operator can confirm from the actual composite video of the foreground video and the background video whether or not the range designation result with the cursor is valid. If it is not valid, the process of repeating the range specification and waiting for a few seconds again is repeated. As a result, it took time to obtain the desired composite video.

  In view of the above points, the present invention provides a chroma key for generating a key signal for replacing the background color of the portion of the foreground image whose range is designated as illustrated in FIG. 1 with the background color as another background image. In the function, it is an object to allow the operator to immediately confirm the range designation result with an actual synthesized video after performing the range designation.

In order to solve the above problems, a chroma key device according to the present invention provides:
A key processing unit that is supplied with a video signal as a foreground video and generates a key signal indicating a synthesis ratio of the foreground video and the background video;
Control means;
An image memory for writing the foreground video,
The control means includes
Based on the fact that information indicating the range specified on the screen is supplied from the outside, a process of sampling pixel data in the specified range of the foreground video written in the image memory;
Based on the result of the sampling, a value of a background color in a color space is obtained, and information indicating the obtained background color value is sent to the key processing means.
The key processing means includes
The key signal is generated by comparing the data of each pixel of the foreground image with the value of the background color indicated by the information sent from the control means.

  Unlike the conventional chroma key device shown in FIG. 2, this chroma key device samples the foreground video written in the image memory instead of sampling the foreground video passing through the inside of the key processing means. Here, writing of one frame of video data to the image memory is completed in one frame period, and a plurality of pixel data in the video data written to the image memory can be sampled in real time. Therefore, it is possible to sample all the pixel data in the designated range in the foreground video in real time.

  Therefore, a key signal can be generated in real time by performing an operation of designating a range of a portion in which a color desired to be a background color is displayed in the foreground video displayed on the screen. As a result, after performing the range designation, the operator can immediately confirm the range designation result from the actual composite video of the foreground video and the background video.

Next, the video composition device according to the present invention is as follows.
A key processing unit that is supplied with a video signal as a foreground video and generates a key signal indicating a synthesis ratio of the foreground video and the background video;
A video signal as the background video, the foreground video, and the key signal are supplied, and a synthesizing unit that synthesizes the foreground video and the background video using the key signal, a video display unit,
Control means for controlling the video display unit, and an image memory for writing video data to be displayed on the video display unit,
The control means includes
The video data of the background color designating screen for designating the range where the background color is displayed from among the colors displayed on the screen is written to the image memory and read from the image memory. Processing to be displayed on the video display unit,
A process of sampling pixel data in a range designated on the background color designation screen among the video data written in the image memory;
Based on the result of the sampling, a value of a background color in a color space is obtained, and information indicating the obtained background color value is sent to the key processing means.
The key processing means includes
The key signal is generated by comparing the data of each pixel of the foreground video with the value of the background color indicated by the information sent from the control means.

  This video synthesizer does not sample the foreground video that passes through the inside of the key processing means like the conventional chroma key device shown in FIG. 2, but samples video data written in the image memory. All of the pixel data in the specified range can be sampled in real time.

  Therefore, a key signal can be generated in real time by performing an operation of specifying a range of a portion where a color desired to be a background color is displayed on the background color specifying screen. As a result, after performing the range designation, the operator can immediately confirm the range designation result from the actual composite video of the foreground video and the background video.

  In addition, since the control means for controlling the video display unit displays the screen for specifying the background color using the image memory for writing the video data to be displayed on the video display unit, video data other than the foreground video is written to the image memory. This makes it possible to display a video other than the foreground video on the video display unit as a background color designation screen.

  According to the chroma key device of the present invention, the operator performs an operation for specifying the range of the portion of the foreground video displayed on the screen in which the color desired to be the background color is displayed, and then displays the range specification result. There is an effect that it is possible to immediately confirm the actual composite video of the foreground video and the background video.

  According to the video composition device according to the present invention, the operator designates a range where the color desired to be the background color is displayed on the background color designation screen, and then immediately designates the range designation result as the foreground video and the background. It is possible to confirm the actual synthesized video with the video, and it is possible to display the video other than the foreground video on the video display unit as the background color designation screen.

[Embodiment of chroma key device according to the present invention]
Embodiments of the present invention will be specifically described below with reference to the drawings. First, an embodiment of a chroma key device according to the present invention will be described.

  FIG. 3 is a block diagram showing an embodiment of the chroma key device according to the present invention. This chroma key device is provided with a key processing circuit 1, which is a hardware circuit for generating a key signal, a CPU 2, an image memory 3, and a video capture device 4. A video signal as a foreground video is supplied to the key processing circuit 1. The key processing circuit 1 is a hardware circuit that generates a key signal from the foreground video and outputs the generated key signal together with the foreground video.

  The foreground video output from the key processing circuit 1 is also sent to the CPU 2 via the video capture device 4.

  Further, the CPU 2 receives range designation information indicating the range designated on the screen from an external operation panel or the like (not shown) (for example, among the foreground video displayed on the screen as shown in FIG. Information generated by the operation of surrounding the portion where the color desired to be the background color is displayed with the cursor) is supplied.

  When the foreground video is supplied from the video capture device 4, the CPU 2 starts processing as shown in FIG. In this process, first, the supplied foreground video is sequentially written in the image memory 3 (step S1). Then, it waits until new range designation information is supplied (step S2).

  When the range designation information is supplied, all the pixel data in the designated range are sampled from the foreground video of the latest frame written in the image memory 3 (step S3). Subsequently, based on this sampling result, an operation for obtaining a background color value in the color space (for example, obtaining an average value of the sampled pixel data in the color space) is performed (step S4). Then, information indicating the obtained background color value is sent to the key processing circuit 1 (step S5), and the process returns to step S2.

  When the key processing circuit 1 receives information from the CPU 2 in step S5 of the processing of FIG. 4, the key processing circuit 1 compares the data of each pixel of the foreground video of the current frame with the value of the background color, for example, the background color. The ratio of the foreground video is 0 at the image position where the difference from the value is less than a certain lower threshold, and the ratio of the foreground video is 1 at the image position where the difference from the background color value is greater than or equal to the certain upper threshold. The ratio of the foreground video is a value between 0 and 1 at an image position where the difference from the background color value is greater than or equal to the lower threshold and less than the upper threshold (the value depends on the magnitude of the difference). Key signal is generated.

  By supplying the key signal, the foreground video, and the video signal as the background video to a synthesis circuit (not shown), the foreground video and the background video are synthesized by the synthesis circuit.

  In this manner, in this chroma key device, the foreground video written in the image memory 3 is not sampled as in the conventional chroma key device shown in FIG. 2, but the foreground video passing through the inside of the key processing circuit 1 is sampled. Sampling. Here, the writing of video data for one frame to the image memory 3 is completed in one frame period, and a plurality of pixel data in the video data written to the image memory 3 are collectively recorded in real time (several fields). Since sampling can be performed within a certain period of time, all the pixel data in a specified range of the foreground image can be sampled in real time.

  In addition, since the background color value calculation processing after the sampling processing and the key signal generation processing in the key processing circuit 1 are also performed in real time (within a period of several fields), the range specified on the screen In response to the supply of the information indicating the key signal, a key signal is generated in real time.

  Therefore, as shown in FIG. 1, a key signal can be generated in real time by performing an operation of designating a range of a portion of the foreground image displayed on the screen where the color desired to be the background color is displayed. As a result, after performing the range designation, the operator can immediately confirm from the actual synthesized video of the foreground video and the background video whether the range designation result is appropriate.

  And even if the range specification result is not valid, the range specification can be redone while checking in real time how the composite video will change, so the desired composite video can be obtained in a short time. be able to.

  FIG. 5 is a block diagram showing another embodiment of the chroma key device according to the present invention, and the same reference numerals are given to the portions common to FIG. In this chroma key device, a CPU 2, an image memory 3 and a video capture device 4 are connected by a PCI bus 5.

  The CPU 2 causes the video capture device 4 to execute writing to the image memory 3 in the processing shown in FIG. 4 instead of directly executing the writing.

  FIG. 6 is a block diagram showing still another embodiment of the chroma key device according to the present invention, and the same reference numerals are given to the portions common to FIG. In this chroma key device, a memory controller 6 is interposed between the CPU 2 and the image memory 3, and a foreground image is sent from the video capture device 4 to the memory controller 6.

  The CPU 2 causes the memory controller 6 to execute the writing to the image memory 3 and the sampling of the pixel data written to the image memory 3 in the processing shown in FIG. 4 instead of directly executing.

  The chroma key device shown in FIGS. 5 and 6 can provide the same effect as described for the chroma key device shown in FIG.

[Embodiment of video composition apparatus according to the present invention]
Next, an embodiment of a video composition device according to the present invention will be described. FIG. 7 is a perspective view showing the external appearance of an embodiment of the video composition apparatus according to the present invention. The video composition device 10 has a shape and size that is larger than that of a notebook personal computer. For example, the video composition device 10 is carried to various venues where events are held, and video signals from video cameras and personal computers are used. Can be used to create video content that introduces the event.

  The video composition apparatus 10 selects an input video at a position corresponding to a keyboard portion of a notebook personal computer, specifies a special effect to be applied to the video (including specification of a background color in the foreground video as described later), etc. An operation unit 11 is provided for performing various operations. The video composition device 10 is provided with a liquid crystal display 12 in the same manner as in a notebook personal computer.

  FIG. 8 is a block diagram showing a circuit configuration of the video composition device 10. The video synthesizing apparatus 10 includes six video input units 20, a video processing unit 30, and a control unit 40.

  The video input unit 20 has input terminals (not shown) for composite signals, S-Video signals, DV signals, RGB signals, SDI signals, etc., and the input video signals are converted into video by a frame synchronizer & resizer 21. After synchronizing with the reference synchronization signal in the synthesizing device 10, the image is converted into SXGA (1280 × 1024 pixels), which is a unified image size in the internal processing of the video synthesizing device 10, and an image size for thumbnail display.

  The video signals of up to six lines whose image size has been converted to SXGA by each video input unit 20 are sent to the video processing unit 30. In the video input unit 20, a frame synchronizer & resizer 21, a local CPU 22, and an Ethernet controller (Ethernet is a registered trademark) 23 are connected by a local bus 24, and each video input unit 20 converts the image size for thumbnail display. The video signals of up to six lines are sent from the Ethernet controller 23 to the Ethernet controller 45 in the control unit 40 via the Ethernet 25 in the video composition device 10.

  The video processing unit 30 includes a cross point unit 31, a key processing circuit 32, a synthesis circuit 33, a local CPU 34, and an NTSC / PAL converter 35. The key processing circuit 32, the synthesis circuit 33, and the local CPU 34 are connected by a local bus 36.

  The cross-point unit 31 includes a video signal supplied as a foreground video to the key processing circuit 32 and a video signal (as a background video supplied to the synthesis circuit 33) from among a maximum of six video signals sent from each video input unit 20. This is a set of switches for selecting a program video that is a background video to be displayed at present and a next video that is a next video to be displayed next).

  The key processing circuit 32 is a hardware circuit that generates a key signal from the foreground video and outputs the generated key signal together with the foreground video.

  From the key processing circuit 32, the foreground video and the key signal are sent to the synthesis circuit 33. The key processing circuit 32 also sends a foreground video to the local CPU 34 via the local bus 36.

  The synthesizing circuit 33 is a circuit that synthesizes the foreground video with the program video using the foreground video and the key signal from the key processing circuit 32 (keying) and switches the background video such as wipe (transition).

  The program video that has undergone the processing of the synthesis circuit 33 is format-converted into an NTSC or PAL video signal by the NTSC / PAL converter 35, and is output from an output terminal (not shown) of the video synthesis device 10. Sent to the video capture device 46. Further, the next video is sent as it is from the synthesis circuit 33 to the local CPU 34 for preview via the local bus 36.

  The control unit 40 is provided with a main CPU 41, a chip set 42 equipped with a graphic processor and a memory controller, an image memory 43, a graphic controller 44, an Ethernet controller 45, and a video capture device 46. The chip set 42, the graphic controller 44, the Ethernet controller 45, the video capture device 46, and the local CPU 34 in the video processing unit 30 are connected to the PCI bus 47.

  The image memory 43 is a memory for writing video data to be displayed on the liquid crystal display 12 (FIG. 7).

  The main CPU 41 sends a command to the local CPU 22 in the video input unit 20 and the local CPU 34 in the video processing unit 30 via the chip set 42 based on the operation of the operation unit 11 (FIG. 7) or the like. The image controller 43 is controlled to perform writing and reading, and the graphic controller 44 is controlled via the chipset 42 to display various screens on the liquid crystal display 12.

  Next, a key signal generation process in the video composition device 10 will be described. FIG. 9 is a flowchart illustrating an example of processing executed by the main CPU 41 in the control unit 40 to cause the key processing circuit 32 in the video processing unit 30 to generate a key signal.

  This process starts when the operation unit 11 supplies a signal indicating that an operation for starting the designation of the background color has been performed. First, the local CPU 34 in the video processing unit 30 is connected to the key processing circuit. The foreground video from 32 is requested to be transmitted to the chipset 42 via the PCI bus 47 (step S11). Then, by controlling the chipset 42, a background color designation screen using the foreground video from the local CPU 34, a program video sent from the NTSC / PAL converter 35 to the video capture device 46, and each video input unit 20 Video data in which a thumbnail image based on the video signal sent to the Ethernet controller 45 is displayed on one screen is written in the image memory 43 (step S12).

  Then, the chip set 42 is controlled to read this video data from the image memory 43 and send it to the graphic controller 44, and the graphic controller 44 is controlled to display this video data on the liquid crystal display 12 (step S13). .

  FIG. 10 is a diagram showing a display example of a background color designation screen, program video, and thumbnail image on the liquid crystal display 12 based on this video data. As in the case shown in FIG. 1, the background color designation screen 50 displays a frame-like cursor 51 whose position and size can be adjusted on the screen on which the foreground video is displayed. The portion where the desired color is displayed is surrounded by the cursor 51. A program video 52 is displayed beside the background color designation screen 50. Under the background color designation screen 50 and the program video 52, six thumbnail images 53 corresponding to the number of systems of the video input unit 20 are displayed.

  As shown in FIG. 9, when step S13 is completed, range designation information indicating the range designated on the background color designation screen is determined from the operation unit 11 (in the example of FIG. 10, the range enclosed by the cursor 51 is confirmed. (Information generated by the operation to be performed) is waited until it is newly supplied (step S14).

  When this information is supplied, the chip set 42 is controlled to sample all the pixel data in the specified range from the video data written in the image memory 43 (step S15). Subsequently, based on this sampling result, an operation for obtaining a background color value on the color space (for example, obtaining an average value of the sampled pixel data on the color space) is performed (step S16). Then, information indicating the obtained background color value is sent to the local CPU 34 in the video processing unit 30 as information addressed to the key processing circuit 32 (step S17).

  Subsequently, it is determined whether or not a signal indicating that an operation for ending designation of the background color has been performed is supplied from the operation unit 11 (step S18). If no, the process returns to step S14. If the answer is yes in step S18, the process is terminated.

  When the information from the main CPU 41 in step S17 of the processing of FIG. 9 is transferred from the local CPU 34, the key processing circuit 32 compares the data of each pixel of the foreground video of the current frame with the value of the background color. For example, the foreground video ratio is 0 at an image position where the difference from the background color value is less than a certain lower threshold value, and the foreground is at an image position where the difference from the background color value is greater than or equal to a certain upper threshold value. The ratio of the foreground video is a value between 0 and 1 at an image position where the video ratio is 1 and the difference from the background color value is greater than or equal to the lower threshold value and less than the upper threshold value (large difference) A key signal is generated such that the value increases accordingly.

  The key signal and the foreground video are sent from the key processing circuit 32 to the synthesis circuit 33, and the foreground video is synthesized with the program video by the synthesis circuit 33. As a result, the program video in which the foreground video is synthesized is also displayed on the liquid crystal display 12 by steps S12 and S13 of the process of FIG.

  In this way, the video composition device 10 does not sample the foreground video passing through the inside of the key processing circuit 32 as in the conventional chroma key device shown in FIG. Sampling the video. Here, the writing of one frame of video data to the image memory 43 is completed in one frame period, and a plurality of pixel data in the video data written to the image memory 43 are collectively recorded in real time (several fields). Since sampling can be performed within a certain period of time, all the pixel data in a specified range of the foreground image can be sampled in real time.

  Also, the background color value calculation processing after the sampling processing and the key signal generation processing in the key processing circuit 32 are also performed in real time (within a period of several fields), so on the background color designation screen. A key signal is generated in real time in response to the supply of information indicating the specified range from the operation unit 11.

  Therefore, a key signal can be generated in real time by performing an operation of specifying a range of a portion of the foreground video where the color to be set as the background color is displayed on the background color specifying screen as illustrated in FIG. it can. Thus, after performing the range designation, the operator immediately determines whether or not the range designation result is valid, and immediately determines the actual synthesized video of the foreground video and the program video (in parallel with the foreground video on the liquid crystal display 12). Program image displayed on the screen).

  And even if the range specification result is not valid, the range specification can be redone while checking in real time how the composite video will change, so the desired composite video can be obtained in a short time. be able to.

  By the way, in this video composition device 10, the main CPU 41 that controls the display of the liquid crystal display 12 displays the background color designation screen using the image memory 43 for writing the video data to be displayed on the liquid crystal display 12. By writing video data other than video in the image memory 43, video other than the foreground video can be displayed on the liquid crystal display 12 as a background color designation screen.

  Therefore, as another example of processing executed by the main CPU 41 to cause the key processing circuit 32 to generate a key signal, an example in which a color palette screen is displayed as a background color designation screen will be described. FIG. 11 is a flowchart showing another example of processing, and steps having the same contents as those in FIG. 9 are denoted by the same reference numerals.

  In this process, first, after executing step S11 having the same contents as the process of FIG. 9, the chip set 42 is controlled, a background color designation screen using a still image in which a plurality of color samples are arranged, The foreground video from the CPU 34, the program video sent from the NTSC / PAL converter 35 to the video capture device 46, and the thumbnail image by the video signal sent from each video input unit 20 to the Ethernet controller 45 are displayed on one screen. Video data to be written into the image memory 43 (step S21). Then, steps S13 to S18 having the same contents as the process of FIG. 9 are executed.

  FIG. 12 is a diagram showing a display example of a background color designation screen, foreground video, program video, and thumbnail image on the liquid crystal display 12 by the processing of FIG. As shown in FIG. 10, the background color designation screen 60 is displayed on a color palette in which a plurality of color samples are arranged in a matrix (for convenience of illustration, each color sample is drawn on a white background). A frame-shaped cursor 61 whose size can be adjusted is displayed, and a portion where a color sample to be used as a background color is displayed is surrounded by the cursor 61. A foreground video 62 and a program video 63 are displayed beside the background color designation screen 60. Under the background color designation screen 60, the foreground video 62, and the program video 63, six thumbnail images 64 are displayed.

  By displaying a screen in which multiple color samples, such as this color palette, are arranged as a background color designating screen, the operation for designating the range in which the color to be used as the background color is displayed can be performed more easily. Is possible.

  When the chroma key device shown in FIG. 3, FIG. 5 or FIG. 6 is applied to this video composition device, for example, an image memory is provided in the video processing unit 30, and the local CPU 34 is provided with FIG. 3, FIG. 6 may be executed as the CPU 2.

  In the embodiment of FIG. 7, the video composition apparatus according to the present invention has a shape and size that can be carried, but the video composition apparatus according to the present invention may be implemented as a stationary apparatus.

It is a figure which illustrates the screen for background color designation | designated which used the foreground image | video. It is a block diagram which shows the example of a conventional structure of the chroma key apparatus which produces | generates the key signal for replacing the color of the part by which the range designation | designated among foreground images was made into a background color with another background image. It is a block diagram which shows one Embodiment of the chroma key apparatus based on this invention. It is a flowchart which shows the process which CPU of FIG. 3 performs. It is a block diagram which shows another one Embodiment of the chroma key apparatus based on this invention. It is a block diagram which shows another one Embodiment of the chroma key apparatus based on this invention. 1 is a perspective view showing an embodiment of a video composition device according to the present invention. It is a block diagram which shows the circuit structure of the image | video synthetic | combination apparatus of FIG. It is a flowchart which shows an example of the process which the main CPU of FIG. 8 performs for key signal generation. It is a figure which shows the example of a display of the screen for background color designation | designated by the process of FIG. It is a flowchart which shows another example of the process which the main CPU of FIG. 8 performs for key signal generation. It is a figure which shows the example of a display of the screen for background color designation | designated by the process of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Key processing circuit, 2 CPU, 3 Image memory, 4 Video capture device, 5 PCI bus, 6 Memory controller, 10 Image composition apparatus, 11 Operation part, 12 Liquid crystal display, 20 Image input part, 21 Frame synchronizer & resizer, 22 Local CPU, 23 Ethernet controller, 24 Local bus, 30 Video processing unit, 31 Crosspoint unit, 32 Key processing circuit, 33 Composition circuit, 34 Local CPU, 35 NTSC / PAL converter, 36 Local bus, 40 Control unit, 41 Main CPU, 42 chipset, 43 image memory, 44 graphic controller, 45 Ethernet controller, 46 video capture device, 47 PCI bus

Claims (4)

A key processing unit that is supplied with a video signal as a foreground video and generates a key signal indicating a synthesis ratio of the foreground video and the background video;
Control means;
An image memory for writing the foreground video,
The control means includes
Based on the fact that information indicating the range specified on the screen is supplied from the outside, a process of sampling pixel data in the specified range of the foreground video written in the image memory;
Based on the result of the sampling, a value of a background color in a color space is obtained, and information indicating the obtained background color value is sent to the key processing means.
The key processing means includes
A chroma key device, wherein the key signal is generated by comparing data of each pixel of the foreground image with a background color value indicated by the information sent from the control means. A key processing unit that is supplied with a video signal as a foreground video and generates a key signal indicating a synthesis ratio of the foreground video and the background video;
A video signal as the background video, the foreground video, and the key signal are supplied, and a synthesizing unit that synthesizes the foreground video and the background video using the key signal, a video display unit,
Control means for controlling the video display unit, and an image memory for writing video data to be displayed on the video display unit,
The control means includes
The video data of the screen for designating the background color for designating the range where the color to be set as the background color is displayed from among the colors displayed on the screen is written to the image memory and read from the image memory. Processing to be displayed on the video display unit,
A process of sampling pixel data in a range designated on the background color designation screen among the video data written in the image memory;
Based on the result of the sampling, a value of a background color in a color space is obtained, and information indicating the obtained background color value is sent to the key processing means.
The key processing means includes
An image synthesizing apparatus, wherein the key signal is generated by comparing data of each pixel of the foreground image with a value of a background color indicated by the information sent from the control means. The video composition device according to claim 2,
The control means includes
The video synthesizing apparatus, wherein the foreground video is written in the image memory as video data of the background color designation screen. The video composition device according to claim 2,
The control means includes
An image synthesizing apparatus, comprising: generating still image data in which a plurality of color samples are arranged, and writing the still image data in the image memory as video data of the background color designating screen.

Images