JP2012205107A - Television intercom device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit a reduced image through the use of a free area in transmitting a non-magnified image.SOLUTION: Each entrance slave unit 1 includes: an image reduction part 12 for reducing an image to be output by a camera 11; an image compression part 13 for compressing image data; a compression rate determination part 14 for changing a compression rate; a first transmission part 18 for relaying data transmitted from the other entrance slave unit 1; and a second transmission part 19 for transmitting to a room master unit 2, the image data to be output by the image compression part 13 and relay data received by the first transmission part 18. The room master unit 2 includes: a transmission part 21 for receiving the multiple kinds of image data; an image composition part 24 for displaying the multiple received images on a monitor 25; and a master unit CPU 29 for designating the entrance slave unit 1 for outputting a captured image by non-magnified image data and the entrance slave unit 1 for outputting the image by reduced image data. The second transmission part 19 includes an image data composition circuit 19a for inserting the reduced image data to the free area of a frame while transmitting the non-magnified image data by frame unit.

Description

  The present invention relates to a television door phone device provided with a camera, and more particularly to a television door phone device including a plurality of entrance cordless handsets for calling a resident and digitizing and transmitting a visitor image, sound, and control signal.

  2. Description of the Related Art Conventionally, there is a television door phone apparatus that digitizes and transmits video signals, control signals, and audio signals using a digital transmission path. Such a TV door phone device is based on the premise that an image captured by a single camera provided in the entrance cordless handset is transmitted and displayed on the monitor of the room base unit, and can be transmitted simultaneously by a plurality of cameras. As such, the data transmission rate is not set. For this reason, when images captured by a plurality of cameras are transmitted simultaneously to the room master, the transmission path is time-divided to reduce the amount of data per screen and send other image data (see, for example, Patent Document 1). ).

JP 2009-159229 A

As described above, when transmitting a plurality of image data at the same time, since the amount of data per image is reduced and other image data is sent, when transmitting a continuous image and displaying it on a monitor as a video, It was a rough video. Considering such a transmission form that minimizes image degradation, prioritizing the images, one image is transmitted without being degraded as much as possible, that is, transmitted without reducing the amount of data as much as possible. A mode is conceivable in which the image is greatly reduced and transmitted as small image data.
However, in the above-described conventional method for time-dividing the transmission path, it is necessary to reduce the transmittable data size of the transmission path for transmitting the image for the same size display as much as the image data for the reduced screen is transmitted. The image data size had to be kept small by increasing the compression ratio. For this reason, it has been impossible to avoid a situation in which the image quality of the 1 × magnification display image deteriorates to some extent.

  On the other hand, data compressed by JPEG or the like has a feature that the data size of one image varies greatly depending on the content of the original video. For this reason, the compressed image data size is transmitted with a certain margin with respect to the transmission path, and is usually limited to an average image with a data amount of about 70 to 80% of the maximum value, and is maximum for the first time in the case of complex video. The compression ratio is adjusted to be close to the value. Therefore, in most cases, the transmission line is used in a state where 20 to 30% is free.

  Therefore, in view of such a problem, the present invention effectively transmits a reduced image by using an empty area when transmitting an equal-sized image, thereby allowing the reduced image to be stored in a room without degrading the equal-sized image. An object of the present invention is to provide a TV door phone device that can be displayed well on a parent device.

In order to solve the above-described problems, the invention of claim 1 is directed to a camera for capturing an image of a visitor, a plurality of entrance cordless handsets having a function of calling and calling a resident, and an image captured by the camera. In the TV door phone device, which has a monitor and a living room base unit having a function of responding to calls from the front door unit, and the plurality of front door units and the home base unit are connected by a cascade connection of digital transmission paths. The entrance unit includes an image reduction unit that reduces the image size of image data output from the camera, an image compression unit that compresses image data output from the camera or the image reduction unit, and a compression that changes the compression rate of the image compression unit. The rate determination unit, the first transmission unit that relays data transmitted from other entrance cordless handsets, and the image data output from the image compression unit and the relay data received by the first transmission unit to the living room base unit To transmit On the other hand, the living room base unit includes a transmission unit that receives a plurality of transmitted image data, an image composition unit that combines images to simultaneously display the received plurality of images on a monitor, and a camera. And an output image control unit that designates an entrance slave device that outputs a captured image as an equal-size image data and an entrance slave device that outputs an image as reduced image data. The second transmission unit transmits the same-size image data in units of frames. It is characterized by having an image data composition circuit for inserting and outputting reduced image data in an empty area of a frame while transmitting.
According to this configuration, even when the data transmission capacity of the digital transmission path between the devices is such that the image data of one camera can be transmitted in the same size image without being reduced, the compression rate of the same size image is changed. Therefore, the reduced image can be transmitted at the same time. Therefore, it is possible to display a compressed image by picture-in-picture or the like while maintaining the image quality of the same size image.

According to a second aspect of the present invention, in the configuration according to the first aspect, the room master unit reads the data size and the reduced image data size of the received equal-size image data, and determines the compression rate of the entrance unit that outputs the reduced image. And a compression ratio operation means for transmitting a compression ratio control signal so as to generate a reduced image having a data size corresponding to the free area of the frame.
According to this configuration, since the display of the reduced image can be controlled to a constant frame rate even if the equal-size image data size changes, the display image by the reduced image displayed on the monitor does not become an awkward operation image and is natural. It is possible to prevent a situation in which the reduced image becomes a still image for a long time or a delay or disturbance of the video occurs.

  According to the present invention, even if the data transmission capacity of the digital transmission path is about the image data of one camera, it is possible to transmit a reduced image at the same time without changing the compression ratio of the same size image. Therefore, it is possible to display a compressed image by picture-in-picture or the like while maintaining the image quality of the same size image.

It is a block diagram which shows an example of the television door phone apparatus which concerns on this invention, and has shown each apparatus with the circuit block diagram. The structure of image data is shown, (A) is the structure of the same-size image and reduced image before composition, and (B) is the structure after composition. The internal structure of the data frame of the equal-size image which inserted reduced image data is shown, and the data structure to the 1st-4th frame shown in FIG. 2 is shown. It is a flowchart which shows the flow which synthesize | combines an image.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a television door phone device according to the present invention, and each device is shown as a circuit block. Here, a configuration including two entrance slave units (first entrance slave unit 1a and second entrance slave unit 1b) 1 and a living room master unit 2 is shown. Each device is cascade-connected by transmission lines L1 and L2 in the order of the first entrance slave unit 1a, the second entrance slave unit 1b, and the living room master unit 2.

The first entrance child machine 1a and the second entrance child machine 1b have the same configuration, a camera 11 for taking an image of a visitor, an image reduction unit 12 for reducing an image taken by the camera 11, and an image for JPEG compression of image data. A compression unit 13, a compression rate determination unit 14 for switching the compression rate of the image compression unit 13, a quantization table generation unit 15 for generating a quantization table for image compression, a microphone / speaker unit 16 for calling, and an audio signal Audio codec unit 17 that compresses / decompresses, first transmission unit 18 that relays signals from the other main unit 1 and the main unit 2, and the front unit connected to the main unit 2 or the main unit 2 side A second transmission unit 19 for communicating with the machine 1 and a call button (not shown) are provided.
The second transmission unit 19 includes an image data synthesis circuit 19a described later. In addition, since the first transmission unit 18 is used when the gateway devices 1 are cascade-connected like the second door device 1b, the first transmission unit 18 of the first door device 1a is a device in this embodiment. Not connected and not used.

  The living room master unit 2 includes a transmission unit 21 for communicating with the entrance slave unit 1, an image decompression unit 22 for decompressing a compressed image transmitted from the entrance unit 1, and an image buffer for temporarily storing the transmitted image data. Unit 23, an image composition unit 24 for generating a display image when a plurality of images are displayed on the monitor 25, a monitor 25 for displaying an image, a microphone / speaker unit 26 for talking, and an audio codec for compressing / decompressing an audio signal Unit 27, operation unit 28 for performing various operations such as response operation and display operation of camera 11, control of compression ratio of captured image of camera 11, control of change of same magnification / compression of image, and control of each block of room base unit And so on.

The image reduction unit 12 of the entrance unit 1 receives the control signal from the living room base unit 2 and reduces the image data output from the camera 11. When receiving an instruction not to reduce, the image reduction unit 12 does not reduce the input image data. Are output to the image compression unit 13. When the room master unit 2 displays the images of both cameras 11 on the monitor 25 at the same time based on a predetermined image display operation of the operation unit 28 or a call operation of the front door unit 1, a captured image of either camera 11 is displayed. Is controlled to output a control signal from the master CPU 29 to the first and second entrance cordless handsets 1a and 1b.
By this control, the captured image of the camera 11 of one of the front door units 1 is reduced, and both images are displayed on the monitor 25 of the living room base unit 2 as picture-in-picture images.

  Based on the control signal from the room master unit 2, the compression rate determination unit 14 sets an appropriate data size when compressing the same-size image, that is, 70 with respect to the maximum value of the frame that is the capacity of the transmission line L 2. The compression rate is set so that the data size is about 80%, and the quantization table generating unit 15 is controlled. On the other hand, when compressing a reduced image, a compression rate is set based on the compression rate control signal from the living room base unit 2 so that data can be transmitted with an empty size of the data frame of the same size image, and a quantization table is generated. The unit 15 is caused to generate a quantization table.

  The compression ratio determination unit 14 is controlled by the living room master unit 2 as follows. The master CPU 29 reads the transmitted data size of the same size image and the empty frame size, and sets the compression rate of the same size image and the compression rate of the reduced image. Specifically, it is determined from the data size of the transmitted normal-size image whether the data amount per frame is appropriate, that is, 70 to 80% with respect to the maximum value of the frame, and the normal-size image is output. A compression rate control signal is output to the compression rate determination unit 14.

  The compression ratio setting for the reduced image is a numerical value obtained by dividing the empty size of one frame of the transmitted equal-size image and the data size of one image of the reduced image by the number of data frames (hereinafter referred to as “divided data size”). If the divided data size is an appropriate ratio to the empty size (the appropriate ratio is preset in the parent CPU 29), the compression ratio of the reduced image is maintained as it was last time. However, if the divided data size exceeds the appropriate ratio with respect to the free size, control is performed to increase the compression ratio, and if the divided data is below the appropriate ratio with respect to the free size, the compression ratio is decreased. A control signal is generated and transmitted to the front door 1.

  As described later, the transmission of the reduced image is performed using the empty area of the data frame of the equal-size image, and thus the operation for optimizing the data size is performed. As a result, for example, in the case where one image of the same size image is transmitted by being divided into 30 frames and one image of the reduced image is transmitted by being divided into 10 frames, the same size image is transmitted. Control is performed so that 10 frames of the reduced image fit in the 30 frames of free space.

  The first transmission unit 18 of the entrance unit 1 receives the image / audio data and relays it to the second transmission unit 19 when there is the cascade-connected entrance unit 1. On the other hand, the control signal and voice data transmitted from the living room base unit 2 via the second transmission unit 19 are relayed and transmitted to the cascade-connected front unit 1. In FIG. 1, the first transmission unit 18 of the second entrance cordless handset 1b receives the image / sound data transmitted from the first entrance cordless handset 1a, relays it to the second transmission unit 19, and the room master unit 2 The control signal from is relayed.

The second transmission unit 19 synthesizes and transmits the image data to the room master unit 2 when transmitting a plurality of image data composed of one equal-size image data and at least one reduced image data to the room master unit 2. An image data synthesis circuit 19a is provided. This image data composition circuit 19a is constituted by a DSP, and when transmitting a plurality of image data composed of one equal-size image data and at least one reduced image data to the room master unit 2, the image data is synthesized and the room parent. Transmit to machine 2.
The second transmission unit 19 transmits the image / sound data transmitted from the first transmission unit 18 to the living room master unit 2, and the image data captured by the camera 11 and the sound data collected by the microphone / speaker unit 26 are transmitted. It is transmitted to the room master unit 2. Furthermore, the audio data transmitted from the room master unit 2 is transmitted to the audio codec unit 17 or the first transmission unit 18.

  Specifically, in the case of the second transmission unit 19 of the second entrance slave unit 1b, data transmission is performed under the control of the master unit CPU 29 of the living room master unit 2, and for example, only the image of the first entrance slave unit 1a is transmitted. Transmits the voice data of the first entrance slave unit 1a to the living room master unit 2 in addition to the relayed image of the first entrance slave unit 1a, and does not transmit the data of the second entrance slave unit 1b. In addition, when the image of the second entrance cordless handset 1b is transmitted as an equal-size image and the image of the first entrance cordless handset 1a is reduced and transmitted, the image data is combined and transmitted, and the second entrance cordless handset is transmitted. The audio data 1b is transmitted. In addition, when only the image of the second entrance slave unit 1b is transmitted as the same size image, the image / sound data of the second entrance slave unit 1b is transmitted to the room master unit 2.

When the data is sent from the second entrance cordless handset 1b, the transmission unit 21 of the living room master unit 2 sends the image data to the image decompression unit 22 and sends the audio data to the audio codec unit 27.
The audio codec unit 27 decompresses the transmitted audio data and outputs it to the microphone / speaker unit 26, compresses the audio collected by the microphone / speaker unit 26, generates audio data, and outputs the audio data to the transmission unit 21. .

  The image composition unit 24 generates a picture-in-picture image, composes it into one image, and outputs it to the monitor 25 when both the normal-size image and the reduced image are transmitted under the control of the master CPU 29. The image data sent to the image decompression unit 22 is decoded into the original image data by the image decompression unit 22 and temporarily stored in the image buffer unit 23. The stored image data is usually sent to the monitor 25 as it is and displayed.

  The TV door phone device configured as described above operates as follows. However, the operation of displaying the visitor image on the monitor 25 of the room master unit 2 by the calling and calling operation from the main unit 1 and displaying the visitor image, and the response operation in the room base unit 2 for the call are the conventional ones. The description is omitted because it is the same, and here, transmission of an image signal when image data is transmitted from both the first entrance terminal 1a and the second entrance terminal 1b will be described with reference to FIGS. . The situation in which the captured images of both cameras 11 are simultaneously transmitted in this manner occurs when a display operation is performed in the living room master unit 2 or when both the front door units 1a and 1b are operated to be called at the same time.

  FIG. 2 is an explanatory diagram of image transmission of the television door phone apparatus of the present invention. FIG. 2A shows the state of each frame before data composition, with the top frame of reduced image data generated and the bottom frame generated. A frame of the same size image data is shown. (B) shows the state of the frame after data composition, and shows a state in which the reduced image data is inserted in the upper part and the reduced image data is inserted into the empty area of the data frame of the same size image and transmitted. In either case, the horizontal axis represents the frame on the time axis, and is given a frame number. The vertical axis represents the transmission band in terms of data size, and the upper limit indicates the maximum amount of data that can be transmitted. FIG. 3 shows the frame data configuration when the compression method is JPEG and the same-size image JPEG data and the reduced image JPEG data are combined. FIGS. 3A to 3D show the data configuration of the first to fourth frames. Show.

  Note that SOI shown in FIG. 3 is a code representing the start of JPEG data in the JPEG format, and EOI is a code representing the end of JPEG data in the JPEG format, and is included in the JPEG data. The same applies to the JPEG data of the reduced image, and the boundary between the same size image and the reduced image or between the reduced images is identified by the SOI or EOI. The data counter value is a value obtained by counting the data size of the data frame, and the maximum value is n. 2 and 3 show a case where one image is transmitted in one frame in the same size image.

  When transmitting the same size image, as described above, in order to eliminate the situation in which the data size that changes from time to time depending on the complexity of the video exceeds the transmission band and cannot be temporarily transmitted, the average video is compressed. The compression rate is set so that the data size is somewhat smaller than the maximum value that can be transmitted. Therefore, as shown in FIG. 2, the size of the same-size image data compressed with JPEG or the like changes from time to time, but there is a free area in the transmission band, and the reduced image JPEG is stored in the free area under the control of the image data synthesis circuit 19a. Data is inserted and transmitted. This will be specifically described below.

When the EOI is transmitted at the end of the same size image JPEG data, the reduced image JPEG data is inserted immediately thereafter. If the reduced image JPEG data fits in one frame, there is no reduced image JPEG data to be sent next, so the frame ends transmission there. If the transmission of the reduced image JPEG data is not completed by the end of the frame, the transmission is interrupted and the transmission of the next frame is started.
In the transmission of the next frame, transmission is started from the beginning of the same size image JPEG data as shown at the beginning (shown in FIGS. 3A to 3D). Transmission is resumed from the continuation of the interrupted reduced image data. When the transmission of the reduced image data is completed during the transmission of this frame, there is reduced image data to be sent next, and the next reduced image data is subsequently transmitted (shown in FIGS. 3B and 3D). . However, the reduced image data to be sent next is the latest frame data that matches the frame number of the same size image at that time. Thereafter, transmission is interrupted at the end of the frame.

  By repeating this, the reduced image JPEG data can be transmitted in parallel without hindering the transmission of the equal-size image JPEG data. However, as a result of transmitting the reduced image in this way, some of the frames of the reduced image are discarded without being transmitted. FIG. 2B shows a situation in which the first, second, fourth, and seventh frames are transmitted, but the third, fifth, and eighth frames that are not transmitted are discarded.

In this way, even in a transmission path that can send only the image data of one camera, an image for the same size display is displayed with a good compression rate and image quality just as when one image is transmitted. In addition, a reduced image can be transmitted at the same time, and a picture-in-picture screen can be displayed well.
Further, even if the data size of the same size image fluctuates, it is controlled so that the display of the reduced image can be transmitted at a constant frame rate. It is possible to display the image with a natural operation, and it is possible to prevent a situation in which the reduced image becomes a still image for a long time, or the image is delayed or disturbed.

  Here, image data when the image data output from the camera 11 of the second door unit 1b is transmitted as the same size image data, and the image data transmitted from the first door unit 1a is reduced image data. The flow of transmission will be specifically described. FIG. 4 is a flowchart showing the flow of image data transmission as viewed from the second entrance cordless handset 1b, and will be described based on this flow.

  When the camera 11 of the second entrance cordless handset 1b starts imaging and starts outputting image data (S1), this image data is transmitted to the living room master unit 2 as equal-magnification image data. Outputs the input image data as it is to the image compression unit 13 without performing the reduction operation. This image data is compressed by the image compression unit 13 (S2), and transmitted to the living room master unit 2 via the second transmission unit 19 and the transmission path L2 (S3). At this time, the second transmission unit 19 starts counting transmission data of one frame (S4).

  When the output of the image data for one frame from the camera 11 is completed (S5), the compression of the image data is completed (S6), and the transmission of the same size image is completed (S7), the second transmission unit 19 transmits the transmission line L1. The transmission of the reduced image data transmitted from the first entrance cordless handset 1a via is started. At this time, when transmission of the previous frame is completed, it is determined whether the transmission of the reduced image is completed (S8). If completed, transmission of the reduced image of the new frame is started (S9). The continuation of the interrupted reduced image is transmitted (S10).

If the frame of the reduced image data that has started transmission is completed before the transmission data counter reaches the maximum value (Yes in S11), the transmission of the reduced image is terminated (S13), and the transmission of the reduced image of a new frame is performed. To start.
On the other hand, if the transmission data counter of the frame reaches the maximum value before the frame of the reduced image data is completed (Yes in S12), the transmission of the reduced image is interrupted (S14), and the transmission of the next frame of the same size image is started. (S15). Thus, returning to the beginning of the flow, the next image data is obtained from the camera 11 (S1), and the compression of the equal-size image data is repeated.
As described above, the reduced image data is transmitted using the empty area of the frame for transmitting the equal-size image data.

In the above-described embodiment, the reduced display screen has the same number of frames as the 1 × display screen, and the image quality is reduced with emphasis on movement. However, a high-quality still image may be transmitted by reducing the number of frames. . Further, the reduced image data is transmitted using only the empty area of the data frame of the equal-size image data, but in addition to this, the empty area of the audio data transmission may be used.
Further, although the front door unit 1 is described as two units, the number may be three or more, and there may be a plurality of reduced image data to be transmitted in an empty area of the same size image data.

  1 .. Entrance child machine 2.. Living room master 11.. Camera 12.. Image reduction unit 13.. Image compression unit 14.. Compression rate determination unit 15. 18 .. First transmission unit, 19... Second transmission unit, 19 a .. Image data synthesis circuit, 21... Transmission unit, 23 .. Image buffer unit, 24 .. Image synthesis unit, 25. ..Master CPU (output image control unit, compression rate operation means)

Claims (2)

A function of responding to a call from a camera for capturing a visitor and a plurality of entrance cordless handsets having a function of calling and calling a resident, a monitor for displaying an image captured by the camera, and the entrance cordless handset In the TV door phone device, wherein the plurality of entrance slave units and the living room master unit are connected by a cascade connection of digital transmission paths.
The entrance unit includes an image reduction unit that reduces an image size of image data output from the camera, an image compression unit that compresses image data output from the camera or the image reduction unit, and a compression of the image compression unit A compression rate determination unit that changes the rate, a first transmission unit that relays data transmitted from another entrance unit, image data output from the image compression unit, and relay data received by the first transmission unit While having a second transmission unit that transmits both to the living room master unit,
The living room master includes a transmission unit that receives a plurality of transmitted image data, an image composition unit that combines images to simultaneously display the received plurality of images on a monitor, and a camera-captured image at an equal magnification image data And an output image control unit for designating an entrance cordless handset that outputs with reduced image data.
The second transmission unit includes an image data synthesizing circuit that inserts and outputs reduced image data in an empty area of the frame while transmitting equal-size image data in units of frames. The living room master reads the data size and the reduced image data size of the received equal-size image data, and outputs a reduced image to the compression rate determination unit of the entrance child machine according to the free space of the frame 2. The television door phone apparatus according to claim 1, further comprising a compression ratio operation means for transmitting a compression ratio control signal so as to generate a reduced image.

Images