JPH06311405A - Image transmission device - Google Patents

Abstract

PURPOSE:To recognize the distance from a camera to an object by a trigonometry in a television telephone, to perform a background deletion by this method, to provide a mean can be performed by both of a transmission side and a reception side in the screen synthesis for the background deletion and to perform an emphasis display of a specified object image. CONSTITUTION:The distance of an object is recognized by two cameras, a shift 5 and a coincidence detection 6. The object image of an object arranged in a designated distance is extracted by a video switch 12 and the image is transmitted. Thus, a background deletion is performed. The contrast of the object image is raised and an emphasis display is performed. A screen and the distance information within the screen is transmitted and a screen synthesizing means operating by the distance information is provided on a reception side. Thus, the screen synthesis for the background deletion can be performed on the reception side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for detecting a distance to an object and an image transmission device having a function of transmitting an image at high speed. In particular, the present invention relates to a background erasing unit suitable for a videophone device that transmits a moving image using ISDN technology and the like, and an image transmitting device using the background erasing unit.

[0002]

2. Description of the Related Art In a conventional videophone device, an image inputted from a video camera is transmitted as it is or after image information is compressed. Therefore, the background of the room in which the videophone device is installed is displayed in addition to the transmission target such as the caller. Therefore, at home, privacy issues such as the room is messy and you do not want to see it,
Problems such as confidentiality arise in the office. In order to solve this, there is a background erasing technique, that is, a technique of discriminating a transmission object, transmitting only the discriminated transmission object, or replacing an image other than the transmission object.

Here, if the distance information from the television camera to the object is obtained, the object image to be transmitted can be discriminated according to the distance information. For example, JP-A-2-266782 and JP-A-3-26682
For example, there is an object such as -38989 that discriminates an object to be transmitted based on the distance from the television camera by using focus information and signal strength.

Another related technology is Japanese Patent Laid-Open No. 57-1.
An object that distinguishes a caller by storing a background image in advance such as 29076 and Japanese Patent Laid-Open No. 2-128584 and comparing it with an image showing the caller. Also,
JP-A-59-168786 and JP-A-62-149287
Those using chroma key technology. In addition, Japanese Patent Laid-Open No. 3-1
26391, the object to be transmitted is discriminated using the outline of the image. Further, as in Japanese Patent Laid-Open No. 1-125085, there is an object in which a portion having a certain constant temperature is discriminated as a caller by using an image showing heat distribution in the image.

[0005]

Many of the techniques for still image processing have a relatively long processing time. In the still image processing technology, the processing time is not a problem because the image transmission itself has time margin. However, in order to process a moving image, it is necessary to follow the movement, so that it is necessary to shorten the processing time.

If a signal other than a normal image such as an image for transmission is used to realize the means for detecting the distance to an object, the TV camera to be used is specialized and the versatility of the TV camera is deteriorated. The deterioration of versatility means that the product becomes expensive.

A first object of the present invention is to provide at low cost a means suitable for processing of moving image transmission to obtain distance information of a plurality of objects in an image and changes in the distance information at high speed. .

A second object of the present invention is to provide an image transmission device using means for discriminating object images within an arbitrary distance.

A third object of the present invention is to provide an image transmission apparatus for extracting and transmitting an object image of an object within an arbitrary distance from an original image, that is, for background erasing.

A fourth object of the present invention is to extract an object image of an object within an arbitrary distance from the original image and transmit a screen obtained by screen-synthesizing an image different from the original image to other parts, that is, An object of the present invention is to provide an image transmission device that changes the background.

A fifth object of the present invention is to synthesize an object image of an object within an arbitrary distance from an original image by transmitting the extracted object image and synthesizing another portion with an image different from the original image on the receiving side. An object is to provide an image transmission device that displays a screen.

[0012]

In order to achieve the above object, means for discriminating an object image by means for detecting the distance of an object using the following three-angle method (binocular vision method, stereo method) is provided. The image transmitting apparatus is configured by the background changing means and the image transmitting means.

The first means for discriminating the object image will be described.
A plurality of TV cameras facing the same direction (same angle) are used. From a plurality of original images obtained from this television camera, a reference image as a reference for comparison and a comparison image to be compared for detecting the distance are prepared. A means for shifting the comparison image, a first comparator for comparing the shifted images, a means for creating distance distribution information in the reference image from the output information of the comparator and the shifted amount, and a distance value for specifying the distance distribution information And a video switch that operates according to the comparison result of the second comparator.

A second means for discriminating the object image will be described.
A plurality of TV cameras are used, which are set at an angle such that an object image arranged at a transmission target distance comes to the same position of a TV camera image. From a plurality of original images obtained from this television camera, a reference image as a reference for comparison and a comparison image to be compared for detecting the distance are prepared. Further, a comparator for comparing the original image and the comparative image and a video switch operated by the output of the comparator are provided.

During the first and second means for distinguishing objects,
A means for simultaneously processing the same distance within a certain range may be provided.

As a first means for replacing the background, a means for synthesizing the screen of the discriminated object image and the separately set background image is provided on the transmission side.

As a second means for replacing the background, the receiving side is provided with means for synthesizing the display screen by superimposing the background image prepared on the receiving side and the transmitted object image.

As a first means for transmitting only the discriminated object image, an image information compression device for skipping transmission of the portion other than the discriminated object image is provided.

As a second means for transmitting only the discriminated object image, there is provided means for synthesizing the screens with arbitrary values (screen brightness, color) for the portions other than the discriminated object image.

As a background image signal source for changing the background, a background image memory for storing an image in communication or an image set separately is provided.

The television camera used in the above means is a general-purpose one so that it can be constructed at a low cost. Therefore, the image transmission device is configured so that the output of the television camera operates using only the video signal.

[0022]

The function of the triangle method will be described. The same object image in the original images obtained from a plurality of television cameras having different installation points facing the same angle (same direction) has a different position in each original image depending on the distance between the objects. This is because the angle of the object viewed from the installation point of the TV camera is different.
From this, the angle viewed from the installation point of the TV camera can be known from the position of the same object image in the original image obtained from the TV camera. Here, the amount by which the comparison image is shifted by the shift unit corresponds to the angle viewed from the television camera. If you know the angle from two points, you can know the distance by the triangle method. In the Trigonometry, the information of the installation point where the TV camera is installed is necessary to determine the position of the target object, but even if the information of the installation point is not given in particular, the relative placement of each object, the relative The target distance can be detected.

The operation of the first means for discriminating the object image of the transmission object will be described. When there is an image portion (corresponding portion) that is matched by the comparison of the first comparator within a certain range of the shift amount obtained by the means for shifting the comparison image, the corresponding portion is an object image that can be discriminated. The amount by which the image is shifted at this time is the detection result of the distance of the object in the object image that can be discriminated. Distance distribution information is a collection of the detection results of the distance of the object over the entire reference image. The control signal of the video switch can be obtained by comparing the distance detection result and the distance distribution information with the designated distance value by the second comparator. If the video switch is operated by the control signal of the video switch, the object image to be transmitted can be cut out (discriminated) from the reference image.

The operation of the second means for discriminating the object images will be described. A plurality of TV cameras are used, which are set at an angle such that the object images arranged at the transmission target distance come to the same position on the TV camera image. According to the first means for discriminating the object images by setting this angle, the screen has already been shifted. From this, the information indicating the corresponding portion is obtained in the output of the comparator that compares the images obtained from the television camera. Since the video switch operates according to the information indicating the corresponding portion, the video switch can cut out (discriminate) an object image arranged within a certain distance from the reference image by the video switch. According to this method, the operation of shifting the image can be performed at the installation angle of the television camera as compared with the first means for discriminating the object images. As a result, when comparing images from the television camera in the image processing apparatus, there is no need for means for shifting the images, or the circuit scale can be reduced. At this time, a distance distribution image composed of information indicating match / mismatch may be created for each part in the reference image used as the reference for comparison.

The means for simultaneously processing a certain range as the same distance, which is provided in the means for discriminating the objects, processes the certain range as the same distance. Therefore, a three-dimensional target object having a distance range is an object image. Discrimination without being cut in the middle of. Further, it is possible to simultaneously discriminate a plurality of object images arranged within a certain range.

The operation of the first means for changing the background will be described. Since the transmitting side is provided with a means for synthesizing the screen, which superimposes the discriminated object image and the separately set background image, the transmitted image is an image with the background replaced. The receiving side displays the transmitted image as it is.

The operation of the second means for changing the background will be described. On the transmitting side, only the discriminated object image is transmitted by means of transmitting only the discriminated object image. Since the means for synthesizing the screen provided on the receiving side synthesizes the background image prepared on the receiving side and the transmitted object image, a screen with the background replaced can be obtained. The screen with this background replaced is displayed on the receiving side.

The operation of the first means for transmitting only the discriminated object image will be described. For the parts other than the discriminated object image, the image information compression device performs the operation of skipping the transmission.For the parts other than the discriminated object image, the operation of skipping the transmission is performed. Instead, only the discriminated object image is transmitted.

The operation of the second means for transmitting only the discriminated object image will be described. For a part other than the discriminated object image, a means for screen composition is set to a specific value (screen brightness, color). , Color) Synthesize the screen with a constant value. Since this composite screen is transmitted, only the discriminated object image is transmitted.

Since the means for transmitting only the object image described above transmits only the discriminated object image, the background is not transmitted.
Therefore, the background is erased.

The operation of the background image memory will be described. In the first means for changing the background, the background image memory provided on the transmitting side as the background image signal source is
Since the image transmitted at the previous communication can be stored, the stored image in the background image memory can be used as the background image. Furthermore, since the image set separately on the transmitting side can be stored, this can be used as the background image. By the second means of changing the background,
The background image memory provided on the receiving side as the background image signal source stores the image transmitted at the start of communication, during communication, or at the time of the previous communication, and thus can be used as the background image. Furthermore, since the image set separately on the receiving side can be stored, the stored image in the background image memory can be used as the background image.

As the main image processing performed in the present invention, there is processing for comparing the image with processing for shifting the image.
It is possible to perform real-time processing of video signals such as. For this reason, the image processing can be speeded up, and it is possible to follow the movement of the screen during moving image transmission.

The image transmission device of the present invention can be applied to, for example, NTSC.
Since it can be configured to operate using a video signal such as PAL or PAL, the TV camera used for the above means is
It is possible to use general-purpose items. As a result, the image transmission device can be constructed at low cost.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an outline of the system on the transmitting side. This figure is a layout view of the transmission side system arranged in a room or the like as seen from above. The TV cameras 1 and 2 are installed at the same height as the floor. The objects A19a and B19b are transmission target objects, and the object C19c is a non-transmission target object to be erased. These images are picked up by the television cameras 1 and 2 to obtain images as shown in FIGS. 3a) and 3b). In FIGS. 3a) and 3b),
The image of the TV camera 1 and the image of the TV camera 2 are different in the positions of the object images A, B, and C because the positions of the TV camera are different, and the distances of the respective objects are different, so that the deviations on the screen can be There is a difference. This is the image transmission device 3 in FIG.
And is transmitted by the communication line 4.

The operation of the transmitting side will be described below. The contents of the image transmission device 3 are shown in FIG. Video signals from the television cameras 1 and 2 are input to the input terminals 15 and 16, respectively, and a transmission signal is obtained at the terminal 17 and transmitted through the communication line 4. A distance and a distance range to be transmitted (here, L1 and L2) are input from the distance designation input 14.

In operation, the image of the television camera 2 is horizontally shifted (shifted) by the shift 5. The output of the shift 5 that has passed through the low-pass filter 8 and the image of the television camera 1 that has passed through the low-pass filter 7 are compared by coincidence detection 6. For the matched image portions, the matching information indicating that the matched portions are written in the distance distribution image memory 9. While changing the shift amount of shift 5,
The comparison and the writing of the coincidence information to the distance distribution image memory 9 are repeated. The shift amount and the range thereof are ranges corresponding to the distance and the distance range input from the distance designation input 14. From this, the distance distribution image shown in FIG. 3c) is obtained in the distance distribution image memory 9. In FIG. 3c), the shaded portion indicates that the distance is from L1 to L2 in the image of the television camera 1.

The low-pass filters 7 and 8 are inserted to prevent malfunction of the coincidence detection 6 due to the deviation of fine patterns in the image. Distance distribution image FIG. 3c) shows the position on the screen of the object image in the distance range to be transmitted. Image of distance distribution image 3
According to c), the video switch 12 is controlled to switch the shaded portion in the distance distribution image to the image of the television camera 1 and the portion other than the shaded portion of the distance distribution image to the background image of the background image memory 11, A background image is combined with a portion other than the object image to be transmitted. This composite image is transmitted to the transmission device 1
The image information is compressed and modulated by 3, and transmitted through the communication line 4. As described above, the background can be replaced without performing transmission other than the target object image to be transmitted.

Instead of the background image used for composition in the video switch 12 in the present embodiment, a no signal from the no signal generator 10 may be used. When the transmission device 13 compresses the image information, the transmission device 13 can stop or skip the transmission of the non-signal portion to shorten the transmission time.

Further, in the video switch 12, an arbitrary fixed value may be used instead of the background image used for screen composition. When image information is compressed by the transmission device 13, a large information compression effect can be obtained in the fixed value portion, so that the transmission time can be shortened.

The structure of the receiving side is shown in FIG. Hereinafter, the operation on the receiving side will be described separately for each case.

A case will be described in which the transmitting side transmits a screen in which the background images of the portions other than the object image to be transmitted are replaced and combined. When communication is started, the receiving side demodulates the signal transmitted by the communication line 4 into a video signal by the transmission device 22 and inputs the video signal to the video switch 26. Video switch 2
6 is fixedly used so as to select the output of the transmission device 22. This allows the sender to see a screen that has been combined and the background has been changed.

A case will be described in which the transmitting side is transmitting a screen in which a portion other than the object image to be transmitted has no signal.
The background image B is set in the background image memory 20 in advance. The mode setting switch 25 is fixed to the no signal detection 23 side. When the communication is started, the receiving side detects a no-signal part in the screen by the no-signal detection 23, and the part of the object image to be transmitted is taken as the image of the transmission device 22, and the no-signal part is displayed on the background image B. By switching the switch 26, the transmission image and the background image B are combined and displayed on the display device 27. The no-signal detection is performed by the no-signal detection 23 detecting a digital code indicating an operation of stopping or skipping the transmission from the data received by the transmission device 22.

A case where the transmitting side transmits a screen in which a portion other than the object image to be transmitted is set to an arbitrary fixed value will be described. In this case, it may be displayed as it is on the receiving side. At this time, the background becomes the deleted screen. Further, as another operation, means for fixing the mode setting switch 25 to the fixed value detection 24 side and detecting the fixed value portion in the image is used.
When the communication is started, the receiving side sets the detected fixed value portion as the background image B stored in the background image memory 20 and the portion other than the fixed value as the transmission image of the transmission device 22. The transmission image and the background image B may be combined by switching the switch 26 and displayed on the display device 27.

Further, as another operation of the receiving side (FIG. 4) of this embodiment, it can be transmitted at the start of communication or at the time of the previous communication and stored in the background image memory 21. This is because the transmission device 22 demodulates the signal transmitted through the communication line 4, and the demodulated image signal is stored in the background image memory. Instead of the background image B synthesized by the video switch 26 described above, the background image A stored in the image memory 21 may be used. At this time, since the background image to be combined is the scene of the sender sent from the sender, there is an effect that the user on the receiver does not feel uncomfortable.

Further, instead of the background image B described above,
The background image C input by the image input device 18 and stored in the background image memory 19 may be used.

At this time, a RAM is provided in the background image memories 19 and 21 so as to be writable, and a background image memory 20 is provided.
Since a fixed value is read for, a ROM can be used.

Further, as another operation of the transmitting side (FIG. 2) of this embodiment, as in the receiving side of this embodiment (FIG. 4), instead of the background image memory 11, the television camera 1 or the image input device inputs in advance. The background image can be used.

Although the mode setting switch 25 is used in this embodiment, an OR circuit may be used instead of the switch. At this time, when either a non-signal or a fixed value is detected, the switch 26 can be automatically switched to the background image side to synthesize the screen.

Although the television cameras 1 and 2 are arranged in the horizontal direction in this embodiment, they may be arranged in the vertical direction. At this time, the shift direction of the shift 5 is the vertical direction.

In the present embodiment, the output of the shift 5 is input to the low pass filter 8 on the transmitting side, but the output of the low pass filter 8 may be input to the shift 5 in the reverse order. At this time, since the frequency band handled by the shift 5 may be narrow, the circuit scale of the shift 5 can be reduced.

The shift amount of shift 5 is input to the distance designation input 14
Although the input distance and distance range are used, a variable offset may be added to the shift amount in order to absorb the error in the mounting angle of the television cameras 1 and 2. At this time, the shift direction of the shift 5 may be the direction in which the vertical component of the offset amount is added to the horizontal direction.

Since the output signal of the television camera 2 is band-limited by the low-pass filter 8, an inexpensive one having a low resolution can be used.

A second embodiment constructed as a system for deleting or replacing the background in a videophone will be described. FIG. 5 shows a basic configuration example of the transmission side system. This figure is a plan view of the system arranged in a room or the like as seen from above, and shows the TV camera 28 and the TV camera 2.
9 sets the angle so that the object A39a comes to the center of the image. The object A39a is an object to be transmitted, and the object D39
d, the object E39e is a non-transmission target object. (Although not shown in FIG. 5 viewed from above, the object E39e is the object A3
It is assumed that the object D39d is located slightly above 9a and the object D39d is located slightly below object A39a).
Imaging is performed at 29, and the images shown in FIGS. 7A and 7B are obtained.

Since the angles of the television cameras 28 and 29 are set so that the object A39a is located at the center of the image, the positions of the object image A are the same in the images of the two television cameras. However, since the objects D39d and E39e have different distances, the positions in the images of the two TV cameras do not match. This is the image transmission device 3 in FIG.
2 and transmits through the communication line 4.

FIG. 6 shows the contents of the image transmission device 32. Video signals from the television cameras 28 and 29 are input to the input terminals 30 and 31, respectively, and a transmission signal is obtained at the terminal 17 and transmitted through the communication line 4. TV camera 29 through LPF36
7 and the image of the TV camera 28 that has passed through the LPF 35 are compared by the matching detection 37, and the matching detection 37 shown in FIG.
Get the output image of. In FIG. 7c), the shaded portion is the coincident portion, and the portion of the object image A in the image of the television camera 28 in FIG. 7a) is coincident. The video switch 33 is controlled by using this coincidence detection 37 output,
The shaded portion shown in FIG. 7c) is an image of the TV camera 28,
By switching the portions other than the diagonal lines in FIG. 7 c) to be the images in the background image memory 38, the portion of the object image A is discriminated from the image of the TV camera 28, and the background is the background image obtained from the background image memory 38. Screen composition. The composite image is converted into a transmission signal by the transmission device 34 and output to the terminal 17.

The receiving side can use the same structure as that described in FIG. 4 of the first embodiment.

In the present embodiment, the screen is shifted by providing a difference in the installation angles of the television cameras 28 and 29, and the shift 5 used in the first embodiment (FIG. 2) is omitted. If the output signals of the television cameras 28 and 29 and the coincidence detection 37 are synchronized, the distance distribution image memory used in the first embodiment is not necessary. In the present embodiment, the distance for designating the transmission object is set only once, and the distance range having the range as in the first embodiment cannot be set, but the circuit configuration becomes simple.

In this embodiment, the television cameras 28, 2
Although 9 is arranged in the horizontal direction, this may be arranged in the vertical direction.

In this embodiment, the background image obtained from the background image memory 38 is used, but instead of this, no signal or any fixed value may be used. Further, as in the first embodiment, a background image previously input by the television camera 28 or the image input device can be used.

A means for shifting an image may be inserted between the LPF 36 and the coincidence detection 37 in order to absorb an error in the mounting angle of the television cameras 28 and 29. Here, the shifting direction may be the horizontal direction plus the vertical direction component. The shift amount can be changed and fine adjustment can be performed.

A third embodiment configured as a background erasing or replacing system will be described by dividing it into a transmitting side and a receiving side with reference to the drawings. FIG. 1 shows an outline of the transmission side system. This figure is a layout of the system installed indoors, etc., as seen from above. The object A19a is a transmission target object, and the objects B19b and C19c are non-transmission target objects to be deleted. These are imaged by the TV cameras 1 and 2 and are shown in FIG.
Images as shown in a) and b) are obtained.

A first transmission side operation example of this embodiment will be described.

FIG. 8 shows the contents of the image transmission device 3. The video signals from the TV cameras 1 and 2 are input terminals 15,
16 and the transmission signal is obtained at the terminal 17 and transmitted through the communication line 4. A distance and a distance range to be transmitted are input from the distance designation input 48. The image of the television camera 2 is horizontally shifted by the shift 43, passed through the LPF 44, and then compared with the image of the television camera 1 passed through the LPF 41 by the coincidence detection 42 based on the signal of the television camera 1 side. A coincident point is detected, and a value corresponding to the shift amount is written in the location of the distance distribution image memory 45 corresponding to the coincident point. The operation of changing the shift amount of the shift 43 and comparing is repeated.

Here, when a shift corresponding to the distance L1 is performed in the shift 43, there is a matching portion, so the value 1 corresponding to the shift amount is written in the corresponding location in the distance distribution image memory 45. Next, in shift 43, when the shift corresponding to the distance L2 is performed, since there is a matching portion, 2 is written in the corresponding location in the distance distribution image memory 45. Next, when the shift corresponding to the distance L3 is performed in the shift 43, since there is a matching portion, 3 is written in the corresponding location in the distance distribution image memory 45. When a shift corresponding to another distance is performed, a value corresponding to the shift amount is written in the location of the distance distribution image memory 45 of the matching portion. When the above operation is performed, the distance distribution image memory 4
5, a distance distribution image as shown in FIG. 9 is obtained. (Fig. 9
For the sake of explanation, the portion written when shifting corresponding to a distance other than L1 to L3 is shown as blank.) This distance distribution image is read in synchronization with the output of the television camera 1 and input to the comparison unit 47. , And a control signal of the video switch 46 is obtained by comparing with the distance designation input 48. In the comparison 47, when the distance is within the designated distance, the output of the television camera 1 is selected, and when the distance is outside the designated distance, the no signal 40 or a fixed value or preset background image memory 50 output is selected. As described above, since the transmission screens are combined, the same operation as in the first embodiment can be performed.

As for the receiving side, the same structure as that described in FIG. 4 of the first embodiment can be used.

A second transmission side operation example of this embodiment will be described.

On the transmitting side shown in FIG. 8, the video signals from the television cameras 1 and 2 are input to the input terminals 15 and 16, respectively, and the transmission signal is obtained at the terminal 17 and transmitted through the communication line 4. The operations of the shift 43, the coincidence detection 42, and the distance distribution image memory 45 are the same as those of the first transmitting side operation example of this embodiment, and the distance distribution image shown in FIG. 9 is obtained in the distance distribution image memory 45. The video switch 46 is controlled by the control 49, and the distance designation input 48 and the comparison 47 are not used at this time.

When the communication is started, the control 49 controls the image switch 46 to select the distance distribution image signal output from the distance distribution image memory 45, and transmits the distance distribution image signal between the transmission device 51 and the communication line 4. After the transmission of the distance distribution image signal, the output of the television camera 1 is selected by the video switch 46 under the control of the control 49, and the output image of the television camera 1 is continuously transmitted by the transmission device 51 and the communication line 4. To transmit.
Then, the distance distribution image signal is intermittently transmitted so as not to deteriorate the transmission frame number of the television camera 1. When a part of the screen changes, the distance distribution image is transmitted in pixel units or pixel block units. At this time, the video switch 46 switches the image screen by screen, and does not perform screen composition.

Next, the structure of the receiving side is shown in FIG. 10, and the operation will be described. In the second operation example of the transmission side of the present embodiment, when communication is started, the distance distribution image memory 62 receives the distance distribution image signal transmitted through the communication line 4 and demodulated by the transmission device 61.
Remember. When the reception of the distance distribution image signal is completed, the image of the television camera 1 is transmitted, so the transmission device 6
The image signal of the television camera 1 demodulated in 1 is selected by the video switch 63 for the transmission device 61 and displayed on the display device 66. Further, the distance distribution image signal transmitted intermittently is stored in the distance distribution image memory 62. The output of the distance distribution image memory 62 is compared with the signal of the distance designation input 48. 6
4, and the control signal of the video switch 63 is obtained. With this control signal, the output of the TV camera 1 is selected when the distance is within the distance designated by the distance designation input 65, and the other image portion is switched to the background image B which is the output of the background image memory 60 to display the display screen. To synthesize. This display screen is displayed on the display device 66.

By the above operation, the receiving side can select which of the object images in the transmitted image of the television camera 1 is to be displayed. The receiving side creates and displays a composite screen in which the background image is used for the parts other than the selected object image.

In this embodiment, the background image B is combined with the portion other than the display image, but the same background image as the receiving side (FIG. 4) of the first embodiment can be used. That is, instead of the background image B, the background image A transmitted at the start of communication or at the previous communication and stored in the background image memory may be used. At this time, since the background image to be combined is the scene of the sender sent from the sender, there is an effect that the user on the receiver does not feel uncomfortable.

Further, instead of the background image B described above,
The background image C input by the image input device and stored in the background image memory 21 may be used.

Further, the shift amount of the shift 43 on the transmitting side is
A variable offset value may be added to the shift amount in order to absorb an error in the mounting angle of the television cameras 1 and 2. At this time, the shift direction of the shift 43 may be the direction in which the vertical component of the offset amount is added to the horizontal direction.

Although the television cameras 1 and 2 are arranged in the horizontal direction in this embodiment, they may be arranged in the vertical direction. At this time, the shift direction of the shift 43 is the vertical direction.

Further, instead of the video switch 63 used in the configuration of the receiving side in FIG. 10, an amplifier 68 with variable gain input may be used. The amplifier 68, as shown in FIG.
The image output of the transmission device 61 is connected to the signal input, the output of the comparison 64 is connected to the variable gain input, and the display device 66 is connected to the output of the amplifier 68. The background image memory 60 is not connected. Although omitted in FIG. 11, the communication line 4 and the distance distribution image memory 6
2 and the distance designation input 64 are connected in the same manner as in FIG. Figure 1
1, the same parts as those in FIG. 10 are denoted by the same reference numerals. The operation on the receiving side at this time is to display a screen in which the selected object image is brighter than the surroundings on the display device 66 by increasing the gain of the amplifier 68 in the part of the object image selected by the output of the comparison 64. You can do it. As a result, the effect of enhancing the understanding of the caller can be obtained by emphasizing the selected object image.

Here, the example in which the amplifier 68 is used on the receiving side has been described, but it may be used on the transmitting side. For example, when the amplifier 68 is used in the configuration (FIG. 8) on the transmission side of the third embodiment, it is used instead of the video switch 46. At this time, the background cannot be erased or the background cannot be replaced. When the background is erased or the background is replaced and a screen in which the selected object image is brighter than the surroundings is obtained, at the input terminal of the video switch 46, the video output signal of the TV camera 1 is output from other video signals. The contrast should be set high. Amplifiers for this purpose may be provided, but since amplifiers are frequently used in each part in an actual configuration circuit, it can be performed by setting gains of these amplifiers.

[0077]

According to the present invention, since the distance information from the television camera to the object can be obtained in the image transmission device or the videophone, the object image of the object to be transmitted can be discriminated from the output image of the television camera. . From this, it is possible to transmit the object image of the object to be transmitted and not transmit the other object images. Further, an image different from the output image of the television camera can be combined with the part other than the object image of the object to be transmitted. From this, you can replace the background or erase the background. Also, the discriminated object image can be highlighted.

By deleting the background, for domestic use, it is necessary to deal with privacy protection such as not wanting to see the room being messy, and to deal with confidentiality problems in the office. Can be done.

Since the object image of the object to be transmitted is transmitted and unnecessary object images are not transmitted, the data compression rate of the image information can be improved as compared with the case where all the output images of the television camera are transmitted.

Since these image processes can be performed at high speed, it is possible to provide a background erasing means suitable for moving image transmission.

The background erasing or replacing process can be performed on the transmitting side or the receiving side of the image transmitting apparatus.

The image transmission device according to the present invention can be constructed at a low cost because a general-purpose product can be used for the television camera used.

[Brief description of drawings]

FIG. 1 is a structural conceptual diagram of a transmitting side according to first and third embodiments.

FIG. 2 is a configuration diagram of a transmitting side according to the first embodiment.

FIG. 3 is a diagram showing images of the television cameras 1 and 2 and a distance distribution image obtained in a distance distribution image memory 9.

FIG. 4 is a configuration diagram of a receiving side according to the first embodiment.

FIG. 5 is a conceptual diagram of a configuration on the transmission side of the second embodiment.

FIG. 6 is a configuration diagram of a transmitting side according to a second embodiment.

FIG. 7 is an explanatory diagram showing an image of a switch control signal obtained at the output of the coincidence detection 37.

FIG. 8 is a configuration diagram of a transmitting side according to a third embodiment.

9 is a diagram showing a distance distribution image obtained in a distance distribution image memory 42. FIG.

FIG. 10 is a block diagram of the receiving side of the third embodiment.

FIG. 11 is an explanatory diagram of an amplifier and its peripheral connections for emphasizing and displaying a selected object image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Television camera 1, 2 ... Television camera 2, 3 ... Image transmission device, 4 ... Communication line, 5 ... Image shift means, 6 ... Match detection, 7 ... Low-pass filter, 8 ... Low-pass filter, 9 ... Distance distribution image memory , 10 ... No-signal generating means, 11 ... Background image memory, 12 ... Switch, 13 ... Transmission device, 14 ... Distance designation input, 15 ... Input end, 16 ... Input end, 17 ... Output end, 18 ... Image input, 19 ... background image memory, 20 ... background image memory, 21 ... background image memory, 22 ... transmission device, 23 ... no-signal detection means, 24 ... fixed value detection means, 25 ... switch, 26 ... switch, 27 ... display device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location H04N 5/272 9186-5C (72) Inventor Sakae Nemoto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Image Information System Co., Ltd.

Claims (15)

[Claims] 1. An image transmission apparatus comprising a plurality of television cameras and means for detecting a distance of an object in the image from a plurality of images obtained from the television camera by a triangle method. 2. A means for displacing original images obtained from a plurality of television cameras and a comparator for comparing the displaced original images are provided, and an object image is discriminated from the original images according to the comparison result and information indicating the amount of displacement. An image transmission device characterized by the above. 3. An image transmitting apparatus according to claim 2, wherein the discriminated object image is transmitted after compressing the information amount. 4. An image transmitting apparatus having means for shifting an original image according to claim 2, wherein the amount of shift of the original image has an offset amount. 5. An image transmission apparatus having a means for shifting an original image according to claim 4, wherein an offset amount by which the original image is displaced is made variable so as to correct deviations of installation angles of a plurality of television cameras. 6. The distance distribution information according to claim 2, wherein for each part in the original image used as a reference for comparison, the distance distribution information formed by information indicating that there is no shifted amount when there is a match or no matching point is created. An image transmission device characterized by: 7. A comparator for comparing original images obtained from a plurality of television cameras set at arbitrary angles different from each other according to claim 1, wherein a plurality of object images are formed in accordance with information indicating the comparison result. An image transmission device characterized by discriminating an arbitrary object image from an original image including the image. 8. The image transmission device according to claim 7, wherein the discriminated object image is transmitted after being compressed with an information amount. 9. The image transmission according to claim 2 or 7, wherein distance distribution information composed of information indicating coincidence / disagreement is created for each part in the original image used as a reference for comparison. apparatus. 10. An image transmitting apparatus according to claim 2 or 7, wherein a synthesized image obtained by screen-synthesizing a discriminated object image and a background image set separately is transmitted. 11. An image transmission apparatus, characterized in that a means for synthesizing a screen by superimposing a transmitted object image and a background image on the receiving side is provided, and the synthesized screen is displayed. 12. The image transmission device according to claim 1, wherein an object image at an arbitrary distance is displayed brighter than other object images. 13. The image transmission device according to claim 1, wherein object images of a plurality of objects arranged within a certain distance range are processed as the same distance. 14. A videophone device according to claim 13, wherein the videophone device is in a background processing mode set at the time of making a call and when making a call. 15. The background image according to claim 11,
An image transmission device characterized by using either fixed image data, image data input at a receiving side, or an image transmitted through a transmission path.