JP2011176764A - Video intercom system, and image transmitting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video intercom system in which, when transmitting a captured video image of a camera through a transmission line to a master unit, a high-quality video image can be transmitted without enlarging a band of the transmission line for transmitting image data. <P>SOLUTION: A slave unit 1 is equipped with: a resolution change section 11 for producing and outputting image data of resolutions VGA and QQVGA from video signals captured by a camera 10; a low-pass/high-pass filter section 13 for separating the produced image data of VGA into high-frequency data and low-frequency data; a high-frequency data thinning section 14 for performing frame thinning on the separated high-frequency data; a low-frequency data thinning section 15 for performing frame thinning on the separated low-frequency data; and a JPEG encoder 16 for compressing image data to be transmitted to a master unit 2. The master unit 2 includes: a JPEG decoder 24; and a high-frequency/low-frequency data combining section 25 for combining the high-frequency data and the low-frequency data to produce image data. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a television intercom apparatus that can confirm a visitor by video, and an image transmission apparatus that transmits image data captured by a camera to a monitor device via a transmission line.

Conventionally, a camera is installed in a slave unit equipped with a call function installed at the entrance to capture a visitor, and the image is displayed on the monitor of the master unit equipped with a response function installed in the dwelling unit. There are image transmission devices such as a TV intercom device that can make a call while checking visitors on a monitor, and a monitoring device that monitors a suspicious person by installing a camera outside a dwelling unit.
In such an image transmission device, in particular, a television intercom device transmits a clear image, that is, high-resolution image data, because the bandwidth of the transmission line connecting the child device and the parent device is small and the data transmission capacity is limited. In order to transmit the data, a device has been devised such as performing data compression to reduce the amount of data for transmission.
For example, in Patent Document 1, a video signal captured by a child camera is compressed using JPEG and transmitted to the parent device, and the compressed data is expanded and displayed on the monitor by the kitchen remote controller (parent device). I let you.

JP 2005-197790 A

As disclosed in Patent Document 1, by compressing and transmitting image data, the amount of data to be transmitted can be reduced without degrading image quality, and a clearer image than before can be transmitted.
However, in order to transmit higher resolution image data, the frame rate had to be reduced. To transmit multiple types of video data at the same time, the encoder compression rate must be increased in addition to reducing the frame rate. I had to. As a result, even if the image quality can be improved, when viewed as a moving image, the video transmitted to the main unit does not move smoothly, or the high-resolution video at the corner is displayed with coarse pixels. Became.

  Therefore, in view of such a problem, the present invention, when transmitting a captured image of a camera to a monitor device such as a master unit via a transmission line, without expanding the band of the transmission line for transmitting image data, An object of the present invention is to provide a television intercom apparatus and an image transmission apparatus capable of transmitting high-quality video.

In order to solve the above-mentioned problems, the invention of claim 1 is directed to a camera that captures a visitor and a slave that has a function of calling a resident, a monitor that displays an image captured by the camera, and a call from the slave. In a TV intercom device that has a master unit that has a function of responding to both of them and is connected via a transmission line, the slave unit generates a plurality of image data with different resolutions from the video signal captured by the camera. A resolution changing unit that outputs the image, a high-frequency / low-frequency filter unit that separates at least the maximum resolution of the converted image data into high-frequency data and low-frequency data, and a separated high At least one of a high frequency data decimation unit that performs frame decimation of low frequency data, a low frequency data decimation unit that decimates frames of separated low frequency data, and a parent A data compression unit that compresses image data to be transmitted to the master unit, while the master unit includes a high frequency data buffer unit that holds high frequency data transmitted via a transmission line, and a low frequency A low-frequency data buffer unit that holds frequency data, a data decompression unit that decompresses compressed image data for display on a monitor, and a low-frequency region that generates image data by combining high-frequency data and low-frequency data / High frequency data composition unit.
According to this configuration, since the image data having the highest resolution is separated into high frequency data and low frequency data by the slave unit, the frame is thinned out, further compressed, and transmitted to the master unit. The image data with higher resolution can be transmitted compared to the configuration in which the data is simply compressed and transmitted.
Therefore, even if the bandwidth of the transmission line is limited, multiple image data can be transmitted to the parent device without degrading the image quality, and as a result, multiple moving images that move smoothly can be displayed on the parent device. Is possible.

According to a second aspect of the present invention, in the configuration of the first aspect, the resolution changing unit outputs the image data at two resolutions of VGA and QQVGA, and the wide / low-pass filter unit is higher than the VGA image data. It is characterized by separating into frequency data and low frequency data.
According to this configuration, the resolution VGA image data is frequency-resolved and frame thinning is performed, so that even if two images of resolution VGA and QQVGA are transmitted simultaneously, a high-resolution and smooth video can be monitored by the main unit. Can be displayed.

According to a third aspect of the present invention, in the configuration according to the first or second aspect, the parent device includes a wireless communication unit and can communicate with the wireless parent device, and the image data received from the child device is displayed on the monitor. And an image data sorting unit that sorts data to be transmitted and data to be transmitted to the wireless master unit.
According to this configuration, image data is automatically sorted and output according to the output destination of the image data, such as a monitor or wireless master unit, so an operation to select multiple types of image data received from the slave unit is required each time Absent. For example, by displaying the image data transmitted by the frequency data on the parent device monitor, a high resolution image can always be displayed on the parent device.

According to a fourth aspect of the present invention, in the configuration according to the third aspect, the master unit stores and controls the video storage unit storing the image data and the predetermined image data distributed by the image data distribution unit in the video storage unit. And a recording control unit.
According to this configuration, since the image data to be recorded is data in a predetermined format, the reproduction operation does not become troublesome. For example, if the data is divided into high frequency data and low frequency data, the storage capacity can be reduced even for high quality image data.

According to a fifth aspect of the present invention, there is provided a monitor having a camera and a camera device that outputs image data captured by the camera, and a monitor that displays an image based on the image data transmitted from the camera device via a transmission line. A high-frequency / low-pass filter unit that separates high-frequency data and low-frequency data by frequency-decomposing the image data captured by the camera; Image data to be transmitted to the monitor device, at least one of a high-frequency data thinning unit that performs frame thinning of the separated high-frequency data, a low-frequency data thinning unit that performs frame thinning of the separated low-frequency data, and a monitor device And a data compression unit that compresses the high frequency data buffer that holds high frequency and low frequency data transmitted via the transmission line. And a low frequency data buffer unit, a data expansion unit that expands compressed image data, and a low frequency / high frequency region that generates image data to be displayed on a monitor by combining high frequency data and low frequency data And a data synthesis unit.
According to this configuration, the image data separated into the high-frequency data and the low-frequency data is thinned out and further compressed and transmitted to the monitor device. The amount can be greatly reduced. Therefore, even if the bandwidth of the transmission line is limited, the monitor device can display a high-quality moving image.

According to the television intercom apparatus of the present invention, the image data having the highest resolution is separated into high-frequency data and low-frequency data by the slave unit, and then thinned out, further compressed, and transmitted to the master unit. Therefore, the amount of data can be greatly reduced, and image data with higher resolution can be transmitted compared to a configuration in which data is simply compressed and transmitted. Therefore, even if the bandwidth of the transmission line is limited, multiple image data can be transmitted to the parent device without degrading the image quality, and as a result, multiple moving images that move smoothly can be displayed on the parent device. Is possible. .
Further, according to the image transmission apparatus of the present invention, the image data separated into the high-frequency data and the low-frequency data is thinned out and further compressed and transmitted to the monitor device. The amount of data can be greatly reduced by minimizing. Therefore, even if the bandwidth of the transmission line is limited, the monitor device can display a high-quality moving image.

It is a block diagram which shows an example of embodiment of the television intercom apparatus which concerns on this invention, and has shown the subunit | mobile_unit and the main | base_unit with the circuit block diagram. It is a timing diagram of the image signal output from the subunit | mobile_unit.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a television intercom apparatus according to the present invention. 1 is a slave unit installed at a front door or the like and operated by a visitor to call a resident, and 2 is a slave unit installed indoors. A master unit 3 for a resident to respond to a call from 1 is a wireless master unit that can communicate with the slave unit 1 by wireless communication with the master unit 2. The subunit | mobile_unit 1 and the main | base station 2 are shown with the circuit block diagram, and both are connected by the transmission line L1.
It should be noted that in both the slave unit 1 and the master unit 2, circuits relating to the call / response, which are the original components of the interphone, are not essential parts of the present invention and are omitted.

  The handset 1 includes a camera 10 that captures a visitor, a resolution changing unit 11 that outputs a video captured by the camera 10 with a predetermined resolution, a multiplexer 12 that outputs different image data in a predetermined order, an image A high-frequency / low-pass filter unit 13 that performs Fourier transform on the data to separate the data into high-frequency data and low-frequency data, a high-frequency data thinning unit 14 that performs a thinning operation on frames of the high-frequency data, and a low-frequency data A low frequency data thinning unit 15 for thinning out a frame, a JPEG encoder 16 for compressing data, a header generation unit 17 for adding a header to individual image data, and a slave unit interface (hereinafter referred to as a slave unit IF) for communicating with the master unit 2 18) etc. The specific operation of each circuit of the slave unit 1 is as follows.

  The resolution changing unit 11 uses a first image data of a first resolution (here, a VGA image) from a video signal such as a video signal captured by the camera 10 and a second resolution (a resolution lower than the first image data). Here, the second image data (QQVGA image) is generated and output alternately.

  The multiplexer 12 separates the first image data and the second image data, outputs the first image data to the high-pass / low-pass filter unit 13, and outputs the second image data to the JPEG encoder 16.

The high frequency / low frequency filter unit 13 performs Fourier transform on the first image data, separates the first image data into high frequency data and low frequency data, and outputs the high frequency data to the high frequency data thinning unit 14. The frequency data is output to the low frequency data thinning unit 15.
The high-frequency data decimation unit 14 and the low-frequency data decimation unit 15 perform frame decimation on the input frequency data at a predetermined ratio set in advance, and output the frequency data obtained by frame decimation to the JPEG encoder 16. Specifically, the number of frames of high-frequency data is reduced by half, and the number of frames of low-frequency data is reduced by a quarter and output.

  Note that the ratio of thinning out frames can be set arbitrarily, but in the case of a TV intercom device, the main purpose is to grasp a person from the captured image, so the low frequency centered on color information Compared with data, high-frequency data centered on contour data is more important, so even if the low-frequency data is greatly reduced, it is unlikely to be an obstacle to grasping a person. Therefore, the data amount of the low frequency data can be greatly reduced, and here, the reduction amount of the low frequency data is doubled as compared with the reduction amount of the high frequency data.

The JPEG encoder 16 compresses the high frequency data, the low frequency data, and the second image data that have been thinned out by the frame using the JPEG method, and outputs the compressed data to the image data header generation unit 17.
The image data header generation unit 17 assigns individual headers to the high frequency data, the low frequency data, and the second image data so that the master device 2 can identify individual image data. Output to IF18. The slave IF 18 sequentially transmits image data to the master 2 via the transmission line L1.

  The master unit 2 includes a master unit interface (hereinafter referred to as a master unit IF) 20 for communicating with the slave unit 1, an image data sorting unit 21 that sorts image data transmitted from the slave unit 1, and temporary high-frequency data. The high frequency data buffer unit 22 for storing, the low frequency data buffer unit 23 for temporarily storing the low frequency data, the JPEG decoder 24 for decompressing the data, the high frequency data and the low frequency data are synthesized, and the image data is regenerated. A high-frequency / low-frequency data combining unit 25, a monitor 26 including, for example, an LCD for displaying the generated video, a memory 27 for storing image data, a recording control unit 28 for controlling recording to the memory 27 and extraction of the image, A wireless transmission unit 29 that transmits a signal to the wireless master device 3, a frame rate control unit 30 that controls the frame rate of image data, and the like are provided. There. The specific operation of each circuit of the parent device 2 is as follows.

  The image data distribution unit 21 distributes image data with reference to header information added to individual image data. Specifically, the second image data having a low resolution is output to the frame rate control unit 30 as data to be transmitted to the wireless master device 3, and the high frequency data and the low frequency data having a high resolution are data to be displayed on the monitor 26. To the high frequency data buffer unit 22 and the low frequency data buffer unit 23. Further, here, the image data to be recorded is the first image data, and the high frequency data and the low frequency data are also output to the recording control unit 28.

  In the high frequency data buffer unit 22 and the low frequency data buffer unit 23, the high frequency data and the low frequency data are temporarily stored and output to the JPEG decoder 24 in order to complement the frames thinned out by the slave unit 1.

The JPEG decoder 24 sequentially extracts data to be displayed on the monitor 26 from each buffer unit, and decompresses the data compressed by the JPEG method in the JPEG encoder 16 of the slave unit 1 to synthesize high-frequency / low-frequency data. To the unit 25.
The high frequency / low frequency data synthesizing unit 25 synthesizes the expanded high frequency data and low frequency data, regenerates the first image data, and outputs the first image data to the monitor 26, which is based on the first image data. Displayed video.

  The recording control unit 28 records the high frequency data and the low frequency data in the memory 27. When the recorded data is reproduced, the image data is read from the memory 27 and output to the high frequency data buffer unit 22 and the low frequency data buffer unit 23.

  The frame rate control unit 30 controls the frame rate of the second image data in order to display an image on the wireless master device 3 and outputs the second image data to the wireless transmission unit 29 at a rate of 3 frames per second, for example.

  The wireless master device 3 includes a display unit 3a for displaying video, and receives and displays the second image data wirelessly transmitted from the wireless transmission unit 29. In addition to the wireless transmission unit 29, the base unit 2 has a wireless reception unit (not shown) that receives a signal transmitted from the wireless base unit 3, and confirms the visitor in the same manner as the base unit 2. It is configured to be able to respond.

  The operation of the television intercom apparatus configured in this way is as follows. However, since the calling operation from the child device 1 and the response operation by the parent device 2 or the wireless parent device 3 which are basic operations of the TV intercom apparatus are the same as those in the prior art, the description is omitted. The flow of the captured video signal of the camera 10 to be activated will be described.

When the camera 10 starts imaging, the first image data and the second image data are generated in the resolution changing unit 11 based on the video signal, and the generated first image data is generated in the high frequency / low frequency filter unit 13. After the Fourier transform, it is separated into high frequency data and low frequency data.
The frequency-separated first image data is subjected to data compression in the JPEG encoder 16 together with the second image data after the frames are thinned out at the above-mentioned predetermined ratio in the high frequency data thinning unit 14 and the low frequency data thinning unit 15. The
The compressed image data is individually assigned a header in the image data header generation unit 17 and is transmitted from the slave unit IF 18 to the master unit 2 via the transmission line L1.

  At this time, image data is output from the child device IF 18 to the parent device 2, for example, in the frame order shown in the timing chart of FIG. 2, D1, D2,... Indicate groups of frames to be transmitted. The frames of the first image data and the frames of the second image data form one group in a predetermined order and are transmitted. However, since the number of frames of low-frequency data transmitted is set to 1/2 of the number of frames of high-frequency data, the frames of low-frequency data are an odd group as shown in FIG. It is transmitted every D1, D3,.

  The image data transmitted to the master unit 2 is received by the master unit IF 20 and transmitted to the image data sorting unit 21. The image data sorting unit 21 sorts data displayed on the monitor 26, data to be recorded, and data to be transmitted to the wireless master device 3. Specifically, as described above, the frequency-resolved first image data is distributed for display on the monitor 26 and recording, and the second image data is distributed to the wireless master device 3.

The first image data distributed for display on the monitor 26 is decompressed by the JPEG decoder 24 via the buffer units 22 and 23 and is displayed as a video signal or the like to be displayed on the monitor 26 by the high / low frequency data synthesis unit 25. Recombined into a signal. The video signal thus regenerated is displayed on the monitor 26.
The first image data distributed for recording is stored in the memory 27 in a state where it is decomposed into high frequency data and low frequency data under the control of the recording control unit 28 when a predetermined recording operation is performed in the master unit 2. Remembered.

  The image data stored in the memory 27 is subjected to playback control of recorded images under the control of the recording control unit 28 when a predetermined playback operation is performed. Specifically, the image data is read from the memory 27 and transmitted to the JPEG encoder 24 via the buffer units 22 and 23. Thereafter, the display control is the same as the display control of the monitor 26. After the data expansion, the video signal is recombined and displayed on the monitor 26.

On the other hand, the second image signal sent from the image data distribution unit 21 to the wireless master unit 3 is set to a predetermined frame rate that can be received by the wireless master unit 3 in the frame rate control unit 30, and the wireless transmission unit 29 performs wireless communication. It is transmitted to the base unit 3.
Thus, when the resident responds to the call from the child device 1 with the parent device 2, it is possible to respond while watching the video displayed on the parent device 2, or when the wireless mother device 3 responds. However, it is possible to respond while watching the video displayed on the wireless master device 3.

As described above, since the image data having the highest resolution captured by the slave unit 1 is separated into the high frequency data and the low frequency data, the frames are thinned out, further compressed, and transmitted to the master unit 2. The amount of data can be greatly reduced, and image data with higher resolution can be transmitted compared to a configuration in which data is simply compressed and transmitted. Therefore, even if the band of the transmission line L1 is limited, two types of images that move smoothly without degrading the image quality can be transmitted to the base unit 2, resulting in a plurality of moving images that move smoothly. Can be displayed on the master unit.
In addition, the resolution VGA image data is frequency-decomposed and frame thinning is performed, so that even if two images of resolution VGA and QQVGA are transmitted simultaneously, a high-resolution and smooth video is displayed on the monitor 26 of the master unit 2. Can be made.
Furthermore, since the image data is automatically distributed in accordance with the output destination of the image data such as the monitor 26 and the wireless master device 3, it is not necessary to select a plurality of types of image data received from the slave device 1 each time, and recording is performed. Since the image data is in a predetermined format, the reproduction operation is not troublesome.
Further, by storing data divided into high frequency data and low frequency data when recording, the storage capacity can be reduced even for high quality image data.

In the above embodiment, two types of image data of resolution VGA and QQVGA are generated and data processing is performed. However, the resolution generated by the resolution changing unit 11 is not limited to this resolution. And QVGA and QQVGA, or a combination with SVGA.
In addition, two types of image data of resolution VGA and QQVGA are generated by handset 1, and frequency resolution and frame thinning are performed only for VGA data with large data, but frequency resolution and frame thinning are performed for QQVGA data. You may do it.
Further, although frame thinning is performed for both high frequency data and low frequency data, only low frequency data may be performed. As described above, in the case of an intercom device, the main purpose is to grasp a person from a captured image. Therefore, low-frequency data centered on color information with little information for human authentication is greatly reduced. There are few obstacles to grasp the person. Therefore, the data amount of the low frequency data can be greatly reduced.

  In the above embodiment, the image data transmission form in the TV intercom apparatus has been described. However, the TV interphone apparatus is an example of the image transmission apparatus of the present invention, and the present invention is not limited to the interphone. The present invention can also be applied to an image transmission apparatus that includes a camera apparatus and a monitor apparatus such as a monitor that includes a monitor that displays an image captured by the camera, both of which are connected by a transmission line. In this case, the configuration of the slave unit 1 shown in FIG. 1 may be applied to the camera device, and the configuration of the master unit 2 may be applied to the monitor device. Image data frequency-separated from the camera device is transmitted to the monitor device. By displaying the image data on the monitor, a high-resolution video can be viewed on the monitor device without extending the bandwidth of the transmission line, and can be recorded efficiently.

  In the case of a surveillance camera, since it is usually sufficient to transmit one type of image data, it is possible to display a high-resolution video on the monitor device by applying the above technique. If a plurality of types of image data are transmitted from the camera device, for example, a monitoring video can be viewed from a portable terminal without providing a resolution changing unit in the monitor device.

  1 ·· Slave unit (camera device) 2 ·· Base unit (monitor device) 3 ·· Wireless base unit 10 ·· Camera 11 ·· Resolution change unit 12 · Multiplexer 13 ·· High frequency / Low-frequency filter unit, 14... High-frequency data decimation unit, 15 .. Low-frequency data decimation unit, 16 .. JPEG encoder (data compression unit), 17 .. Image data header generation unit, 21. 22 ··· High frequency data buffer unit, 23 ·· Low frequency data buffer unit, 24 · · JPEG decoder (data decompression unit), 25 · · High frequency / low frequency data synthesis unit, 26 · · Monitor, 27 · · · Memory (video storage unit) 28.. Recording control unit 29 29 Wireless transmission unit (wireless communication unit) 30 Claim rate control unit L 1 Transmission line

Claims (5)

A camera for capturing a visitor and a slave unit having a function of calling a resident; a monitor for displaying a captured image of the camera; and a master unit having a function of responding to a call from the slave unit In a TV intercom device where both sides are connected via a transmission line,
The slave unit generates a plurality of image data having different resolutions from a video signal captured by the camera, and outputs a resolution change unit;
Among the converted image data, at least the highest resolution image data, a high frequency / low frequency filter unit that separates into high frequency data and low frequency data,
A high-frequency data thinning unit that performs frame thinning of the separated high-frequency data, and a low-frequency data thinning unit that performs frame thinning of the separated low-frequency data, and
A data compression unit for compressing image data to be transmitted to the master unit,
The base unit is a high-frequency data buffer unit that holds the high-frequency data transmitted through the transmission line;
Similarly, a low frequency data buffer unit for holding the low frequency data transmitted,
A data decompression unit for decompressing compressed image data for display on the monitor;
A television intercom apparatus, comprising: a low frequency / high frequency data synthesizing unit that generates image data by synthesizing the high frequency data and the low frequency data. The resolution changing unit outputs image data at two resolutions of VGA and QQVGA, and the wide / low-pass filter unit separates the VGA image data into high-frequency data and low-frequency data. The television intercom apparatus according to claim 1, wherein: The master unit includes a wireless communication unit and can communicate with a wireless master unit,
3. The television intercom apparatus according to claim 1, further comprising an image data sorting unit that sorts image data received from the slave unit into data to be displayed on the monitor and data to be transmitted to the wireless master unit. The master unit has a video storage unit and a recording control unit that controls recording,
4. The television intercom apparatus according to claim 3, wherein the image data distribution unit distributes predetermined image data to the video storage unit. Image transmission having a camera device that outputs image data captured by the camera and a monitor device that includes a monitor that displays video based on the image data transmitted from the camera device via a transmission line A device,
The camera device has a high frequency / low frequency filter unit that performs frequency decomposition on image data captured by the camera and separates the data into high frequency data and low frequency data,
A high-frequency data thinning unit that performs frame thinning of the separated high-frequency data, and a low-frequency data thinning unit that performs frame thinning of the separated low-frequency data, and
A data compression unit for compressing image data to be transmitted to the monitor device,
The monitor device includes a high frequency data buffer unit that holds high frequency and low frequency data transmitted via the transmission line, and a low frequency data buffer unit;
A data decompression unit for decompressing the compressed image data;
An image transmission apparatus comprising: a low frequency / high frequency data synthesizing unit that generates image data to be displayed on the monitor by combining the high frequency data and the low frequency data.

Images