JP2003051963A - Wireless image transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless image transmission system including a digital FPU device, wirelessly transmitting image data resulting from processing a video signal from a camera by an image coder and receiving image data and outputting the image data to an image decoder, automatically matching the transmission rate of the image data with a transmission rate of the digital FPU device for simplifying rate settings. SOLUTION: Stuffing data equivalent to a difference between the clock rate of a clock signal received by a transmitter side digital FPU device and a transmission rate of the transmitter side digital FPU device are inserted periodically to image data, transmission data to which header information denoting an interval of the stuffing data and clock rate information denoting a data rate of the image data before insertion of the stuffing data are added are transmitted to a receiver side digital FPU device, and the receiver side digital FPU device detects the header information from the transmission data to eliminate the stuffing data, so as to recover the image data and the clock signal on the basis of the clock rate information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless image transmission system for transmitting image data of a video signal from a camera to a remote place.

[0002]

2. Description of the Related Art In recent years, an FPU device of a wireless image transmission system for wirelessly transmitting image data of a video signal from a camera to a remote place is shifting from an analog transmission system to a digital transmission system. Digital FPU of digital transmission system
Unlike the analog transmission system, the device uses an encoding device that encodes a video signal and an audio signal, so that the data amount of the original signal can be compressed and data can be transmitted at a lower transmission rate. In the digital transmission method, the coding rate of each data can be changed in various ways depending on the content and amount of data to be transmitted, and the rate of the transmission data can be changed. It has been necessary to set the conversion rate and the transmission rate of the digital FPU device on the transmission side and the reception side, respectively, so that the rates of both devices match.

[0003]

In the digital FPU device of the wireless image transmission system of the prior art, the coding rate of the coding device and the digital FPs on the transmitting side and the receiving side are used.
It was necessary to operate both devices by matching the transmission data rate of the U device.

The present invention can automatically operate at the transmission rate of the digital FPU device even if the encoding rate of the encoding device does not match the transmission data rate of the digital FPU device, that is, the encoding of the encoding device. It is to be able to operate at the rate of the transmission data of the digital FPU device independent of the rate.

[0005]

In order to achieve the above object, the wireless image transmission system is as follows.

Image data obtained by encoding a video signal at a predetermined encoding rate is wirelessly transmitted by a digital FPU transmitter, and the image data transmitted by the wireless image is digital FPU.
In a wireless image transmission system for demodulating by a receiving device, a wireless image transmission of the image data is performed by matching a coding rate of the image data with a transmission data rate of the digital FPU transmitting device and the digital FPU receiving device. It was done.

Further, in matching the coding rate of the image data with the transmission data rate of the digital FPU transmitting apparatus and the digital FPU receiving apparatus, the coding rate of the image data and the digital FPU transmitting apparatus and the digital FPU The stuffing data in an amount equivalent to the difference from the rate of the transmission data of the FPU receiver is periodically inserted into the image data.

Further, information indicating the section in which the stuffing data is inserted is added to a predetermined position to the image data in which the stuffing data is inserted.

Specifically, the digital FPU device is as follows. In a digital FPU device of a wireless image transmission system for wirelessly transmitting image data obtained by encoding a video signal from a camera by an image encoding device to a remote place, a clock signal from the image encoding device in a transmitter of the digital FPU device. Is input to the external clock counter section to perform counting operation. The counter value of the external clock counter section is sequentially transferred to the stuffing encoding section that inserts the stuffing data into the image data. In addition, the time counter section is caused to count for a predetermined time by the reference clock signal of the transmitting section of the digital FPU device, and the result of the counter value of the time counter section is sequentially transferred to the stuffing encoding section.

The stuffing encoding section is
The difference between the counter values output from the external clock counter section and the time counter section is calculated. Further, the stuffing encoding unit controls the amount of stuffing data periodically inserted in the image data from the image encoding device based on the difference in the counter value so as to be equivalent to the difference, and the stuffing encoder of the digital FPU device is controlled. Data transmission is performed according to the transmission rate of the transmitter. At this time, the digital FP on the receiving side
The header information and the clock rate information indicating the stuffing data portion in the stuffing data are provided so that the receiving unit of the U device can distinguish the original image data from the stuffing data and reproduce the clock signal rate of the original image data. Are added respectively.

Further, the CPU control unit performs control for causing the rate of the clock signal output from the transmission clock generation unit of the digital FPU device to follow the rate of the transmission data including the stuffing data inserted in the image data.

In the receiving section of the digital FPU device on the receiving side, the stuffing decoding section for removing the stuffing data reads the header information in the received transmission data and separates it into original image data and stuffing data, and separates the separated image data. Are temporarily stored in the coding rate control memory unit. Also, the stuffing decoding unit also reads clock rate information of the original encoding rate of the image data in the received transmission data, and the clock generation unit based on the clock rate information, the digital FPU on the transmission side.
A clock signal of the rate input to the apparatus is generated, the image data stored in the memory unit for encoding rate control is read, and is output to the image decoding apparatus.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a digital FP according to an embodiment of the present invention.
It is a figure which shows the structure of the wireless image transmission system at the time of operation of U device.

FIG. 2 shows a digital FP according to an embodiment of the present invention.
It is a figure which shows the structure of the transmission control part of a U transmitter.

FIG. 3 shows a digital FP according to an embodiment of the present invention.
It is a figure which shows the structure of the reception control part of a U receiver.

FIG. 1 shows a camera 1 for capturing a video signal of a subject on the transmitting side, a digital FPU transmitter 51 for wireless image transmission, an antenna 51A for transmitting and receiving high frequency signals,
52A, and a digital FPU receiver 5 for reproducing image data and a clock signal from a high frequency signal on the receiving side.
2. An image decoding device 7 for converting image data into a video signal and a monitor 8 for displaying the video signal are arranged, and a digital FPU transmitter 51 and an antenna 51 for transmitting and receiving.
The configuration of a wireless image transmission system including A, 52A, and a digital FPU receiver 52 is shown.

The image encoding device 2 includes a camera 1 and a digital F
The transmission control unit 3 of the PU transmission device 51 is connected, and the transmission high frequency unit 4 is connected to the transmission control unit 3. Further, the reception high frequency unit 5 and the reception control unit 6 of the digital FPU receiving device 52 are connected, and the reception control unit 6 and the monitor 8 are connected to the image decoding device 7. Then, the antenna 51A and the antenna 52A face each other, and the wireless transmission of the transmission data including the stuffing data in the image data is performed.

The operation of the configuration of the wireless image transmission system shown in FIG. 1 will be described. The video signal from the camera 1 is image-encoded by the image encoding device 2 to obtain the image data 1
A clock signal 9 together with 0 is supplied to the transmission controller 3. The transmission control unit 3 supplies the transmission high-frequency unit 4 as transmission data in which stuffing data and additional information described later are inserted in the image data. In the transmission high frequency unit 4,
The signal of the transmission data is converted into a high frequency signal and the antenna 51
A digital F on the receiving side via A and the antenna 52A
The signal is transmitted to the reception high frequency unit 5 of the PU receiver 52. The high frequency signal received by the high frequency receiving section 5 is reproduced as a reception transmission data signal 20 and a reception clock signal 21. Then, the reception control unit 6 reproduces the original image data 9 and the clock signal 10 from the stuffing data and the supplementary information from the reception transmission data signal 20, and the image encoding device 7
Is supplied to. The image data 9 image-decoded by the image decoding device 7 is output to the monitor 8 as a video signal and displayed.

Next, the digital FPU transmitter 51 of FIG.
The operation of the transmission control unit 3 will be described. The image encoding device 2 in FIG. 1 outputs the clock signal 9 and the image data signal 10 to the transmission control unit 3.

First, the clock signal 9 taken into the transmission control section 3 is inputted to the external clock counter section 11. The external clock counter unit 11 outputs the internally counted counter value to the stuffing encoder unit 12 in order to determine the clock rate of the input clock signal 9. Further, the time counter unit 14 counts with the clock signal generated from the reference clock generation unit 15 in the transmission control unit 3, and outputs the count value to the stuffing encoding unit 12. In the stuffing encoder 12, the counter value of the external clock counter 11 and the time counter 14
The data rate of the image data is detected by the clock signal 9 from the image encoding device 2 based on the difference from the counter value of. At the same time, in order to follow the transmission data rate of the digital FPU transmitter 51, the image data signal 1
The data amount of the stuffing data 18 to be periodically inserted into 0 is calculated. The stuffing encoding unit 12
The image data signal 10 and the stuffing data 1 are calculated from the calculated data amount of the stuffing data and the insertion period.
8 is generated, and the data switching unit 19 switches the image data signal 10 and the stuffing data 18 to form the transmission data 3A, which is supplied to the transmission high frequency unit 4 in the next stage. And antenna 51
It is sent from A.

Further, in addition to the image data signal 10 and the stuffing data 18, the transmission data 3A is provided with additional information 12b of header information indicating the stuffed data section and clock rate information indicating the rate of the clock signal 9. . With this additional information 12b, the reception control unit 6 of the digital FPU receiver 52 on the receiving side reads the additional information 12b including the header information and the clock rate information added to the transmission data 3A, and thereby the clock signal 9 and the image data The signal 10 can be reproduced. Then, the CPU control unit 17 performs control for causing the transmission clock signal output from the transmission clock generation unit 13 to follow based on the clock rate information from the stuffing encoding unit 12.

Next, the operation of the reception controller 6 of the digital FPU receiver 52 on the receiving side for receiving the high frequency signal of the transmission data 3A and reproducing the image data signal 10 and the clock signal 9 will be described with reference to FIG.

The high frequency signal of the transmission data 3A received via the antenna 52A is demodulated by the reception high frequency 5 and output to the reception control section 6 as the reception transmission data 20 and the reception clock signal 21. From the reception transmission data signal 20 demodulated by the reception control unit 6, header information indicating the insertion period of the stuffing data input to the stuffing decoding unit 22 and periodically inserted, and the reception clock signal 21.
The clock rate information 22b indicating the clock rate is read.

Then, the stuffing decoding unit 22
Then, the enable signal 22a for separating the image data signal 10 and the stuffing data 18 is generated from the header information indicating the stuffing data period, and the data separator 2 is generated.
5 is output. The data separator 25 is the image data 2 obtained by removing the stuffing data from the received transmission data 20.
5a is stored in the encoding rate control memory unit 26 by the reception clock signal 21. Further, the clock signal generating unit 23 reproduces the same clock signal 9 as the clock signal 9 of the digital FPU transmitter on the transmitting side from the clock rate information 22b indicating the data rate of the image data 25a. By the reproduced clock signal 9, the image data signal 25a stored in the encoding rate control memory unit 26 is read out and output to the image decoding apparatus 7.

The image decoding device 7 inputs the image data 10 together with the clock signal 9 and decodes the image to output a video signal on the monitor 8.

[0027]

According to the present invention, by inserting / removing the stuffing data into / from the image data and adding the header information and the clock rate information, the rate of the image data of the image device of the image encoding device or the image decoding device can be digitalized. Since it is automatically adjusted to the transmission data rate of the FPU device,
Digital FP on the transmitting and receiving sides prior to wireless image transmission
It is possible to operate the wireless image transmission system without changing the rate between the U apparatus and the image apparatus.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a wireless image transmission system showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a transmission control unit of the digital FPU device of the present invention.

FIG. 3 is a configuration diagram of a reception control unit of the digital FPU device of the present invention.

[Explanation of symbols]

1: camera, 21: reception clock signal, 2: image encoding device, 3: transmission control unit, 3A: transmission data, 4: transmission high frequency unit, 5: reception high frequency unit, 25: data separation unit, 6:
Reception control unit, 7: image decoding device, 8: monitor, 9: clock signal, 10: image data signal, 11: external clock counter unit, 12: stuffing encoding unit,
12a: enable signal, 12b: additional information, 13: transmission clock generation unit, 14: time counter unit, 15: reference clock generation unit, 17: CPU control unit, 18:
Stuffing data signal, 19: data switching section, 2
0: reception transmission data signal, 21: reception clock signal, 2
2: stuffing decoding unit, 22a: enable signal, 22b: clock rate information, 23: clock generation unit, 23a: clock signal, 25a: image data 25
a, 26: memory unit for encoding rate control, 51A, 52
A: Antenna

Claims (3)

[Claims] 1. A digital FPU transmitting apparatus wirelessly transmits image data obtained by encoding a video signal at a predetermined encoding rate, and the image data transmitted by the wireless image is digital FPU.
In a wireless image transmission system for demodulating by a receiving device, a wireless image transmission of the image data is performed by matching a coding rate of the image data with a transmission data rate of the digital FPU transmitting device and the digital FPU receiving device. Characteristic wireless image transmission system. 2. The image data coding rate according to claim 1, wherein the coding rate of the image data is matched with the coding rate of the transmission data of the digital FPU transmitter and the digital FPU receiver. A wireless image transmission system, wherein stuffing data in an amount equivalent to a difference between transmission data rates of the digital FPU transmission device and the digital FPU reception device is periodically inserted into the image data. 3. The invention according to claim 2, wherein the image data in which the stuffing data is inserted,
Further, the wireless image transmission system is characterized in that information indicating a section in which the stuffing data is inserted is added to a predetermined position.