JP2002010253A - Image transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image transmission system which enables transmission to both fixed stations requiring high-definition transmission and mobile units attaching great importance to information on the same channel with narrow bandwidth. SOLUTION: A transmission system 15 has encoders 2 and 3 which input sequential scanning image signals 18 and output compressed image signals 50 and 51, a multiplexer 4 which outputs multiple signals 52, and a transmission part 6 which modulates and sends the multiple signals 52. A receiving system for fixed stations 16 has a demodulator 10 which receives transmission signals 52 and outputs compressed image data 56 and 57, decoders 8 and 9 which generate image signals 58 and 59, and a dot density converter 7 which outputs sequential scanning image signals 60. A receiving system for mobile units 17 has a demodulator 13 which receives transmitted signals 54, converts them to demodulated signals 61 and outputs compressed image data 62, and a decoder 12 which expands the compressed image data 62 and generates image signals 63.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmission system, and more particularly to transmission of an image signal using digital terrestrial broadcasting using multi-carriers, which is intended for a mobile object where information of an image is relatively important. The present invention relates to an image transmission system that simultaneously performs transmission for a fixed station requiring high-quality images with a small bandwidth.

[0002]

2. Description of the Related Art In recent image transmission, not only high-quality image transmission between a plurality of fixed stations but also image transmission mainly for information provision for mobile objects has been a tendency.

[0003] For example, orthogonal frequency division multiplexing (OFDM: Orthogon), which is one of the multi-carrier systems.
al Frequency Division Mul
It is known that transmission of digital terrestrial broadcasting using the (Tiplex) method has a long symbol period and is resistant to ghosts due to the adoption of a guard interval period. .

In the OFDM system, the modulation method can be easily changed for each carrier by using the fast Fourier transform. Therefore, for high-quality transmission to a fixed station in the same channel, 16QAM (a relatively large amount of information) is used. Qu
addrture Amplitude Modula
Tion) or phase and amplitude modulation by 64QAM can be used. For this reason, it is possible to transmit a sequentially scanned image having a large amount of information. Therefore, it is suitable for display devices that require progressive scanning signals, such as liquid crystal projectors, liquid crystal panels, and plasma displays, which have been actively developed in recent years. Especially effective.

[0005] In transmission for a mobile body requiring information rather than image quality, phase modulation such as differential QPSK can be used in consideration of level fluctuation such as fading.

[0006]

In the conventional image transmission system described above, the amount of information that can be transmitted is generally limited because the channel bandwidth is limited, and high image quality for a plurality of fixed stations is required. However, it is difficult to perform transmission for a mobile device and transmission for a mobile unit in the same channel.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image transmission system capable of performing high-quality transmission to a fixed station and transmission to a mobile unit that emphasizes information on a single channel with a small bandwidth. .

[0008]

According to the image transmission system of the present invention, the image signals sequentially scanned are input to the frame dividing section of the transmitting station, and the first and second images are interlacedly scanned by distributing the image signals for each scanning line. The first and second image signals that have been converted into the first and second interlaced scans are image-compressed by first and second encoder units, respectively, in order to increase transmission efficiency, and the first and second image signals are compressed. The compressed image signal is multiplexed by a multiplexing unit for transmission on one channel, and the first compressed image signal is coded and interleaved mainly for a fixed station to perform modulation, and the second compressed image signal is multiplexed. The signal is coded and interleaved for the mobile station to perform modulation, and the output modulated signal is converted and output to a transmission signal by a transmission unit. In the reception system for the fixed station, the transmission signal is received. The demodulated signal is input to the demodulation signal, and the demodulated signal is input to the demodulation unit, where the demodulation is performed in reverse to the modulation for the fixed station and the modulation for the mobile station, which are modulated in the transmitting station, and deinterleaving and After decoding, the first and second compressed image signals are output, and the first and second compressed image signals are output.
Are converted into first and second image signals which are interlacedly scanned by the first and second decoder units, respectively, and are synthesized by the pixel density conversion unit to convert the sequentially scanned high quality image signals. In the receiving system for the mobile station, the demodulation unit demodulates only the modulation signal for the mobile station, and then performs deinterleaving and decoding to output a compressed image signal.The compressed image signal is converted by a decoder unit. , And outputs an interlaced image signal.

There is provided a transmitting system for transmitting an image, a receiving system for a fixed station and a receiving system for a mobile unit for receiving a transmitted image, wherein the transmitting system converts the sequentially scanned image signals into first and second image signals. A frame division unit that converts and outputs an interlaced scanning image signal; first and second encoder units that compress the first and second interlaced scanning image signals, respectively; and outputs the first and second encoder units. A multiplexing unit that outputs a multiplexed signal multiplexed for transmitting the first and second compressed image signals through one channel; and a multiplexing unit that outputs the first and second compressed image signals included in the multiplexed signal. A modulating unit that performs coding and interleaving and outputs a modulated signal that has been subjected to different modulation; and a transmitting unit that converts the modulated signal into a transmission signal and transmits the signal. A first receiving unit that receives the transmission signal transmitted from the transmission system and converts the transmission signal into a first demodulated signal; demodulates the first demodulated signal, performs deinterleaving and decoding, A first demodulation unit for outputting first and second compressed image data; and a first and second unit for performing interlaced scanning of the first and second compressed image data output from the first demodulation unit, respectively. First and second decoder units for converting the image signals into image signals; selecting the first and second image signals output from the first and second decoder units;
A pixel density conversion unit that converts and outputs a progressively scanned image signal; and wherein the receiving system for a mobile object receives the transmission signal transmitted from the transmission system and converts the transmission signal into a second demodulated signal. A second demodulation unit that demodulates the second demodulated signal, performs deinterleaving and decoding, and outputs third compressed image data; and a second demodulation unit that outputs the third compressed image data. And a second decoder unit for decoding the compressed image data of the second image and converting the decoded image data into one image signal obtained by interlaced scanning.

A first receiving unit for receiving the transmission signal transmitted from the transmission system and converting the transmission signal into a first demodulated signal; demodulating the first demodulated signal; Deinterleaving and decoding,
A first demodulator for outputting second compressed image data and an error detection signal; first and second interlaced scans of the first and second compressed image data output from the first demodulator; First and second decoder units for converting the first and second image signals output from the first and second decoder units into two image signals. First and second interpolation units for outputting image signals;
A delay unit that outputs a delay control signal obtained by delaying the error detection signal; and a pixel density conversion unit that selects the first and second interpolation image signals, converts the output into a sequentially scanned image signal, and outputs the scanned image signal using the delay control signal. ; Characterized by having;

A second receiving unit for receiving the transmission signal transmitted from the transmission system and converting the transmission signal into a second demodulated signal; demodulating the second demodulated signal; Deinterleaving and decoding, and third,
A second demodulator for outputting fourth compressed image data and an error detection signal; and a third demodulator output from the second demodulator.
Third and fourth decoders for respectively decoding the fourth compressed image data and converting them into third and fourth image signals obtained by interlaced scanning; and a delay for outputting a delay control signal obtained by delaying the error detection signal. And a decoder selecting unit that selects and outputs one of the third and fourth image signals according to the delay control signal.

A second receiving unit for receiving the transmission signal transmitted from the transmission system and converting the transmission signal into a second demodulated signal; demodulating the second demodulated signal; Deinterleaving and decoding, and third,
A second demodulation unit that outputs fourth compressed image data and an error detection signal; a delay unit that outputs a delay control signal obtained by delaying the error detection signal; A decoded signal selection unit for selecting and outputting the output third and fourth compressed image data; and a decoder unit for decoding the selected and output compressed image data and converting the image data into an interlaced image signal. It is characterized by doing.

Further, the second interlaced scanning image output from the frame dividing unit is input between the frame dividing unit and the second encoder unit of the transmission system, and the number of scanning lines is reduced. A second thinning unit for reducing the number of data per scan line and outputting the data to the second encoder unit; and the second decoder unit and the pixel density conversion included in the fixed-station receiving system. Interpolating an image signal output from the second decoder unit and outputting an interpolated image signal to the pixel density conversion unit.

Further, the first and second image signals output from the first and second decoder units included in the fixed-station receiving system are interpolated, and the interpolated image signals are interpolated into the pixel density conversion unit. And an interpolation unit that outputs the data to

[0015]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the image transmission system of the present invention.

This embodiment shown in FIG. 1 comprises a transmission system 15 for transmitting an image, a reception system 16 for a fixed station for receiving a transmission image, and a reception system 17 for a mobile body.

The transmission system 15 transmits the progressively scanned image signal 1
8 is input, the sequentially scanned image is converted to generate two interlaced scanned images, and the
9 and an interlaced scanning image signal 20 and a frame dividing unit 1 for outputting an interlaced scanning image signal 20.
G (Moving Picture ExpertsG
encoder-2, which outputs a compressed image signal 50 that has been subjected to compression such as (loop) -2, and an encoder unit 3, which outputs the interlaced image signal 20 as a compressed image signal 51 that has been subjected to compression such as MPEG-2. A multiplexing unit 4 that multiplexes the compressed image signals 50 and 51 and the compressed image signals, audio signals, control signals, and the like of another system so that they can be transmitted in a band of one channel, and outputs a multiplexed signal 52; A modulation unit 5 performs encoding, interleaving, modulation, and the like on the signal 52 to output a modulation signal 53, and a transmission unit 6 converts the modulation signal 53 into a transmission signal 54 and transmits the signal.

The fixed-system receiving system 16 receives a transmission signal 54, converts it into a demodulated signal 55, and outputs the demodulated signal 55.
1, a demodulation unit 10 for deinterleaving and decoding the demodulated signal 55 and outputting compressed image data 56 and 57 such as a compressed image signal, an audio signal, and a control signal, and an image signal 58 obtained by expanding the compressed image data 56. A decoder unit 8 for generating
A decoder unit 9 for expanding the compressed image data 57 to generate an image signal 59, and outputs a sequentially scanned image signal 60 sequentially scanned from two interlaced interlaced image signals 19 and 20 included in the image signals 58 and 59, respectively. And a pixel density conversion unit 7.

The mobile receiving system 17 receives the transmission signal 54, converts it into a demodulated signal 61, and outputs the demodulated signal 61. The receiving unit 14 deinterleaves and decodes the demodulated signal 61 to perform a compressed image signal and audio processing. It has a demodulation unit 13 that outputs compressed image data 62 such as a signal and a control signal, and a decoder unit 12 that expands the compressed image data 62 and generates an image signal 63.

FIG. 2 is a diagram showing conversion of an image signal.

Referring to FIG. 2, the progressively scanned image signal 18
Indicates that the data is distributed to the interlaced scanning image signal 19 obtained by the first interlaced scanning and the interlaced scanning image signal 20 obtained by the second interlaced scanning for each scanning line.

Next, the operation of the present embodiment will be described in more detail with reference to FIGS.

The progressively scanned image signal 18 that has been sequentially scanned is input to the frame division unit 1. The input progressive scanning image signal 18 is treated as a separate signal for each scanning line, so that the first interlaced scanning image signal 19 and the second
Is converted to the interlaced scanning image signal 20 obtained by the interlaced scanning.

The sequentially scanned image signal 18 is converted into an interlaced scanning image signal 19 and an interlaced scanning image signal 20 for each scanning line. The interlaced scanning image signal 19 is input to the encoder unit 2 and converted into a compressed image signal 50, and at the same time, the interlaced scanning image signal 20 is input to the encoder unit 3 and converted into a compressed image signal 51. Here, the encoder unit 2 and the encoder unit 3 perform compression by the MPEG2 system, for example, to obtain compressed image signals 50 and 51. The compressed image signal 5 sent from the encoder unit 2 and the encoder unit 3 to the multiplexing unit 4
0 and 51 are multiplexed as a multiplexed signal 52 so that they can be transmitted in the band of one channel.

The multiplexing unit 4 also multiplexes a signal (not shown) input from another system, for example, an audio signal, a control signal, and another compressed image signal. The multiplexed multiplexed signal 52 is output to the modulating unit 5. For example, the first compressed image signal 50 is subjected to encoding, interleaving, modulation, and the like mainly set for a fixed station, and the second compressed image The signal 51 is subjected to encoding, interleaving, modulation, and the like set for the mobile object and output. Since the encoding set for the fixed station has a relatively good reception condition,
It is possible to set the redundancy to be smaller than for a mobile object having a relatively poor reception condition. Therefore, the transmission efficiency is improved, and the signal can be transmitted in a small band.

Also, in the interleaving, the setting of the time interleaving can be shortened, which leads to a reduction in the circuit scale.

As for the modulation method, transmission efficiency can be increased by using amplitude phase modulation such as 16QAM or 64QAM for transmission to a fixed station, which is a relatively good transmission path free from fading or the like. By using phase modulation such as differential QPSK for transmission for transmission, fading resistant transmission becomes possible. The modulation for each carrier can be changed relatively easily by performing modulation using the Fourier transform and the OFDM method that performs batch processing.

The modulation signal 53 output from the modulator 5 is
The signal is converted into a transmission signal 54 by the transmission unit 6 and output.
The transmission signal 54 passes through the propagation path,
6 and the receiving unit 14 of the receiving system 17 for mobiles.

The receiving unit 11 of the receiving system 16 for fixed stations
The transmission signal 54 input to the demodulation signal 5
5 and output to the demodulation unit 10. The demodulation unit 10 demodulates the demodulated signal 55 into both a demodulated signal for a fixed station and a demodulated signal for a mobile unit, and performs deinterleaving and decoding, which are processes opposite to those on the transmitting side, to obtain two compressed image data. 56 and 57 are output. The two output compressed image data 56 and 57 are output to two decoder units 8 and 9, respectively, and are converted into a first interlaced image signal 58 and a second interlaced image signal 59. Thereafter, the pixel density is converted by the pixel density conversion unit 7 for each scanning line and sequentially output as a scanning image signal 60.

The transmission signal 54 mainly transmitted to the receiving unit 14 of the mobile-use receiving system 17 is converted into a demodulated signal 61 by the receiving unit 14 and output to the demodulation unit 13. The demodulation unit 13 demodulates the demodulated signal 61 as a demodulated signal for a mobile object, performs deinterleaving and decoding opposite to that on the transmitting side, and outputs compressed image data 62. The output compressed image data 62 is input to the decoder unit 12, and outputs a second interlaced image signal 63.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

In FIG. 3, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

Except for the fixed station receiving system, the transmitting system and the mobile receiving system are the same as those in the first embodiment shown in FIG.

The fixed station receiving system 25 differs from the fixed station receiving system 16 of FIG. 1 in that an interpolator 23 is newly provided at the output of the decoder unit 8 and an interpolator 21 is newly provided at the output of the decoder unit 9. The difference is that a pixel density converter 22 for selecting and outputting the interpolated image signals 68 and 67 output from the interpolator 21 and the interpolator 21 and a delay unit 24 for controlling the same are used. Note that a delay control signal 66 obtained by delaying the error detection signal 65 generated by the demodulation unit 10 by the delay unit 24 is used as a control signal of the pixel density conversion unit 22.

The interpolating sections 23 and 21 convert the interlaced image signals 58 and 59 into interpolated image signals 68 and 67 which are sequentially scanned by interpolation and output. The pixel density converter 22 selects and outputs one of the input interpolation image signals 67 and 68 based on the delay control signal 66.
The delay unit 24 delays the input error detection signal 65 by a required time and outputs a delay control signal 66.

The interpolating section 23 outputs the first interlaced image signal 58 output from the decoder section 8 as it is, and at the same time, interpolates and outputs a new scanning line from the preceding and succeeding scanning lines. Similarly, the decoder unit 9 outputs the image signal 59 obtained by the second interlaced scanning as it is, and at the same time, interpolates and outputs a new scanning line from the preceding and succeeding scanning lines. The output of the image signal 58 of the decoder unit 8 and the output of the image signal 59 of the decoder unit 9 input to the pixel density conversion unit 22 are selected for each screen using the delay control signal 66 output from the delay unit 24. And output.

With the above operation, reception interference due to reflected waves from an airplane or the like generated at the time of reception for a fixed station, or reception while maintaining high image quality even when there is an influence of fixed interference waves. Can be.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

In FIG. 4, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

The transmitting system and the receiving system for fixed stations are the same as those of the first embodiment shown in FIG.

The mobile receiving system 30 differs from the mobile receiving system 17 of FIG. 1 in that a new decoder 27 is used, and the outputs of the decoder 12 and the decoder 27 are selected and output by the decoder selector 28. It is a point to do. Note that the control signal of the decoder selection unit 28 is used as the demodulation unit 10
, The delay control signal 70 obtained by delaying the error detection signal 65 generated by the delay unit 29 is used.

The decoder 27 converts the compressed image data 56 into a first interlaced image signal 71. The decoder section 12 converts the compressed image data 57 into a second interlaced image signal 72. The decoder selection unit 28 selects one of the two input image signals 71 and 72 based on the delay control signal 70 and outputs the selected one. Delay unit 29
Delays the input signal by a necessary time and outputs it.
Here, in the modulation unit 5 of the transmission system 15, for example, both the first compressed image signal and the second compressed image signal are subjected to encoding, interleaving, modulation, and the like set for a mobile object and output. I do.

The demodulation unit 10 demodulates both demodulated signals, performs deinterleaving and decoding which are processes reverse to those on the transmitting side, and outputs two compressed image data 56 and 57. The output first compressed image data 56 and second compressed image data 57 are output from the image signal 7 obtained by the first interlaced scanning by the decoder unit 27 and the decoder unit 12, respectively.
First, the image signal 72 is converted and output to the second interlaced scanning image signal 72. The outputted first interlaced image signal 71 and the second interlaced image signal 72 are selected and output by the decoder selecting unit 28 in frame units. Here, the error detection signal 65 generated by the demodulation unit 10 is
By using the delay control signal 70 delayed in step 9 and selecting the signal in the decoder selecting unit 28, when the carrier is partially disturbed due to co-channel interference or the like, the non-disturbed carrier is used. Images can be reproduced.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

In FIG. 5, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

The transmitting system and the receiving system for fixed stations are the same as those in the first embodiment shown in FIG.

The mobile receiving system 33 is different from the mobile receiving system 17 of FIG. 1 in that the compressed image data 56 and 57 output from the demodulator 10 are decoded by the decoded signal selector 3.
This is a point selected and output at 1. Note that the decoded signal selection unit 3
As the one control signal, a delay control signal 75 obtained by delaying the error detection signal 65 generated by the demodulation unit 10 by the delay unit 32 is used.

The decoded signal selection unit 31 converts the two input compressed image data 56 and 57 using the delay control signal 75
Select one of them and output. The delay unit 32 delays the input signal by a necessary time and outputs the signal.

Here, in the modulator 5 of the transmission system 15, both the first compressed image signal and the second compressed image signal are subjected to encoding, interleaving, modulation, and the like set for the mobile body and output. And The demodulation unit 10 demodulates both demodulated signals, performs deinterleaving and decoding which are processes reverse to those on the transmitting side, and outputs two pieces of compressed image data 56 and 57. The output first compressed image data 56 and second compressed image data 57 are input to the decoded signal selection unit 31 and are output to the decoder unit 12 after selection. Delay control signal 7 selected by decoded signal selector 31
By using a signal obtained by delaying the error detection signal 65 generated by the demodulation unit 10 by the delay unit 32, if the carrier is partially disturbed by co-channel interference or the like, It becomes possible to reproduce an image using a carrier.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention.

In FIG. 6, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

Except for the transmitting system and the receiving system for fixed stations, the receiving system for mobiles is the same as that of the first embodiment shown in FIG.

The transmitting system 35 is different from the transmitting system 15 of FIG. 1 in that the second interlaced scanning image signal 76 output from the frame dividing unit 1 is input to the thinning unit 34 to reduce the number of scanning lines. The point is that the data is output to the encoder unit 3 after the number of data of the scanning lines is reduced.

The difference between the fixed-station receiving system 37 and the fixed-station receiving system 16 of FIG. 1 is that the image signal 80 output from the decoder 9 is interpolated by the interpolating unit 36 and becomes an interpolated image signal 81. The point is that it is output to the pixel density conversion unit 7.

In the transmission system 35, the thinning section 34 outputs the input interlaced scanning image signal 76 after thinning the number of horizontal scanning lines to reduce the number of data of one scanning line. The interpolating unit 36 of the fixed-station receiving system 37 interpolates the data decimated and reduced by the decimating unit 34 from the surrounding data to create original data or data similar to the original data.

In the transmission system 35, for example, a second interlaced scanning image signal 76 of the two interlaced scanning images output from the frame dividing unit 1 is input to the thinning unit 34.

The thinning section 34 thins and reduces the number of horizontal scanning lines to an arbitrary number, and further reduces the number of dots in one scanning line. This is the same as, for example, down-converting a high definition video to an NTSC video. The image signal 77 thinned out by the thinning unit 34 is output to the encoder unit 3.

In the fixed-station receiving system 37, the image signal 80 corresponding to the decimated second interlaced scanning image output from the decoder 9 is output to the interpolation unit 36, and the decimated and reduced data is output. Is interpolated from the surrounding data to create original data or data conforming to the original data, and output as an interpolated image signal 81. This is the same as, for example, up-converting an NTSC video to a high-definition video. Then, the interpolated image signal 81 corresponding to the interpolated second interlaced image and the image signal 58 corresponding to the first interlaced image are synthesized by the pixel density conversion unit 7 to create a sequentially scanned image. By doing so, a high-quality image can be reproduced.

FIG. 7 is a block diagram showing a sixth embodiment of the present invention.

In FIG. 7, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

Except for the receiving system for fixed stations, the transmitting system and the receiving system for mobile units are the same as those in the first embodiment shown in FIG.

The difference between the fixed-station receiving system 39 and the fixed-station receiving system 16 of FIG.
An interpolation signal 38 obtained by interpolating the image signal 58 output from the image signal 58 and the image signal 59 output from the decoder unit 9 by the interpolation unit 38 is output to the pixel density conversion unit 7.

In the receiving system 39 for the fixed station, the thinned-out second interlaced image signal 59 output from the decoder 9 and the first interlaced image signal 58 output from the decoder 8 are interpolated. The data is output to the section 38, and the thinned-out and reduced data is interpolated from the data of the two image signals to output the original data or an interpolated image signal 82 based on the original data. Then, the interpolated second interlaced interpolated image signal 82 and the first interlaced image signal 58 are selected for each scanning line by the pixel density conversion unit 7, and sequentially scanned images are created. High quality images can be reproduced.

As described above, in the configuration of FIG. 1, the sequentially-scanned image signal 18 sequentially scanned by the frame division unit 1 on the transmission side is used.
Is input and converted into two interlaced scanning image signals 19 and 20 which are interlacedly scanned by distributing each scanning line. The two interlaced scanning image signals 19 and 20 that have been interlaced are image-compressed by the two encoder units 2 and 3, respectively, in order to increase transmission efficiency. After the two compressed image signals 50 and 51 are multiplexed by the multiplexing unit 4 for transmission on one channel, the one compressed image signal 50 is mainly subjected to encoding and interleaving for fixed stations. Modulation, and another compressed image signal 51 is coded and interleaved for a mobile station, modulated, and output. The output modulated signal 53 is converted into a transmission signal 54 for transmission in the transmission section 6 and output.

On the receiving side that receives the transmission signal 54, first, in a high-quality fixed-station receiving system, the transmission signal 54 is input to the receiving unit 11, converted into a demodulated signal 55, and output. In the demodulation unit 10 to which the demodulation signal 55 is input, demodulation is performed in reverse to the modulation for the fixed station and the modulation for the mobile body, which are modulated on the transmission side, and deinterleaving and decoding are performed. 56 and 57 are output. Two compressed image data 56 and 57 are two image signals 58 and 59 interlaced and scanned by two decoder units 8 and 9, respectively.
, And by combining them in the pixel density conversion unit 7, a sequentially scanned high-quality progressively scanned image signal 60 can be obtained.

In the mobile receiving system, the demodulation section 13 demodulates only the modulated signal for the mobile body, and then performs deinterleaving and decoding to output the compressed image data 62. The output compressed image data 62 is output to the decoder unit 12.
, And the image signal 63 obtained by the interlaced scanning can be obtained.

In the configuration of FIG. 3, two interlaced image signals 58 and 59 output from the two decoders 8 and 9 are input to two interpolators 23 and 21, respectively, interpolated and sequentially scanned. Two interpolated image signals 68 and 67 are created. Obtaining a sequentially scanned high-quality image by inputting two sequentially scanned interpolated image signals 68 and 67 output from the two interpolating units 23 and 21 to the pixel density converting unit 22 and selecting and outputting the same. Can be.

In the configuration shown in FIG. 4, the two compressed image signals multiplexed in the modulation section described in FIG. 1 are subjected to encoding, interleaving, and the like for a mobile object, modulated, and output. In the receiving system for mobile units, the receiver 11, demodulator 10, and two decoders 27 and 12 used in the receiving system for fixed stations are used, and the two interlaced image signals 71 and 72 are used as the decoder selector 28. Output to
By selecting and outputting one of them, the decoder selecting section 28 can obtain an interlaced image signal with reduced noise and the like.

In the configuration of FIG. 5, the two compressed image signals multiplexed in the modulation section described in FIG. 1 are encoded and interleaved for a mobile station, modulated, and output. In the system for the mobile station, the two compressed image data 56 and 57 are output to the decoded signal selecting unit 31 using the receiving unit 11 and the demodulating unit 10 used in the receiving system for the fixed station. The decoded signal selection unit 31 selects one of the compressed image data 56 and 57 and outputs it to the decoder unit 12, and converts it by the decoder unit 12 to obtain a more accurate interlaced image signal.

In the configuration of FIG. 6, one of the two interlaced image signals output from the frame division unit 1 described with reference to FIG. 1 is input to the thinning unit 34, and the number of scanning lines and the number of scanning lines are reduced. The number of data is thinned out and converted into an image signal 77 which is skipped and scanned. In the fixed-station receiving system 37, the interpolated and interpolated image signal 80 of the two interlaced image signals 58 and 80 output from the two decoder units 8 and 9 is interpolated by the interpolation unit 36. Interpolated image signal 8 not skipped
Create 1. The pixel density conversion unit 7 selects and outputs the interlaced image signal and the interlaced image signal that has not been thinned out from the original, so that the image signal can be converted into a high-quality sequentially scanned image signal.

In the configuration of FIG. 7, one of the two interlaced image signals output from the frame division unit described with reference to FIG. 1 is input to the thinning unit and the number of scanning lines and the number of data of one scanning line are determined. Is converted to an interlaced image signal. In the receiving system 39 for fixed stations, 2
The thinned interlaced image output from the two decoder units 8 and 9 and the two image signals 58 and 59 that are only interlaced are output to the interpolating unit 38, and the interpolated interpolated image that is not thinned out is output. A signal 82 is created. The image signal 82 that has been skipped and scanned without being thinned out and the image signal 58 that has been skipped and scanned that has not been thinned out from the original are combined and output by the pixel density conversion unit 7 so that they are sequentially scanned into high quality image signals. can do.

[0073]

As described above, the image transmission system of the present invention can compress and multiplex and transmit two image signals distributed for each scanning line in a channel having a limited bandwidth. This has the effect that transmission for a mobile object that emphasizes information can be transmitted with a small bandwidth at the same time as high-quality transmission.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an image transmission system according to the present invention.

FIG. 2 is a diagram showing conversion of an image signal.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a sixth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 frame division unit 2 encoder unit 3 encoder unit 4 multiplexing unit 5 modulation unit 6 transmission unit 7 pixel density conversion unit 8 decoder unit 9 decoder unit 10 demodulation unit 11 reception unit 12 decoder unit 13 demodulation unit 14 reception unit 15 transmission system 16 Fixed station receiving system 17 Moving object receiving system 18 Progressive scanning image signal 19 Interlaced scanning image signal 20 Interlaced scanning image signal 21 Interpolation unit 22 Pixel density conversion unit 23 Interpolation unit 24 Delay unit 25 Stationary reception system 27 Decoder unit 28 Decoder selection unit 29 Delay unit 30 Receiving system for mobile unit 31 Decoded signal selection unit 32 Delay unit 33 Receiving system for mobile unit 34 Decimation unit 35 Transmission system 36 Interpolating unit 37 Receiving system for fixed station 38 Interpolating unit 39 Receiving system for fixed station 50,51 Compressed image No. 52 Multiplexed signal 53 Modulated signal 54 Transmission signal 55 Demodulated signal 56, 57 Compressed image data 58, 59 Image signal 60 Sequentially scanned image signal 61 Demodulated signal 62 Compressed image data 63 Image signal 65 Error detection signal 66 Delay control signal 67, 68 interpolated image signal 70 delay control signal 71,72 image signal 75 delay control signal 76 interlaced image signal 77 image signal 80 image signal 81,82 interpolated image signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/08 H04N 7/08 Z 7/081

Claims (7)

[Claims] An image signal sequentially scanned is input to a frame division unit of a transmitting station, and is converted into first and second image signals that are interlaced by allocating each scanning line, and the interlaced scanning is performed. The first and second image signals are image-compressed by first and second encoder units, respectively, in order to increase transmission efficiency, and the compressed first and second compressed image signals are 1
The first compressed image signal is multiplexed by a multiplexing unit for transmission on one channel, and the first compressed image signal is coded and interleaved and modulated mainly for a fixed station, and the second compressed image signal is multiplexed for a mobile station. The modulated signal that has been subjected to encoding and interleaving is converted and output as a transmission signal by a transmission unit. In the reception system for the fixed station, the transmission signal is input to a reception unit and converted and output as a demodulated signal. In the demodulation unit to which the demodulated signal is input, demodulation is performed in reverse to the modulation for the fixed station and the modulation for the mobile station, which are modulated in the transmitting station, and the first and second demodulators perform deinterleaving and decoding. 2 are output, and these first and second compressed image signals are converted into first and second image signals which are interlacedly scanned by the first and second decoder sections, respectively, and the pixel density conversion is performed. A high-quality image signal that is sequentially scanned by combining in the unit is output.In the receiving system for the mobile station, the demodulation unit demodulates only the modulation signal for the mobile station, and then performs deinterleaving, decoding, and compression. An image transmission system, comprising: outputting an image signal; converting the compressed image signal by a decoder unit; and outputting an interlaced image signal. 2. A transmitting system for transmitting an image, a receiving system for a fixed station and a receiving system for a mobile unit for receiving a transmitted image, wherein the transmitting system converts the sequentially scanned image signals into first and second image signals. A frame division unit for converting and outputting the image data into two interlaced scanning image signals;
A first method for compressing the second interlaced image signal,
A second encoder unit; and a multiplexing unit that outputs a multiplexed signal obtained by multiplexing the first and second compressed image signals output by the first and second encoder units for transmission on one channel. A modulator that encodes and interleaves the first and second compressed image signals included in the multiplexed signal and outputs modulated signals that have been subjected to different modulations;
A transmission unit that converts the modulated signal into a transmission signal and transmits the transmission signal, wherein the reception system for fixed stations receives the transmission signal transmitted from the transmission system and converts the transmission signal into a first demodulated signal. 1; a first demodulation unit for demodulating the first demodulated signal, performing deinterleaving and decoding, and outputting first and second compressed image data; and The first and second output
And first and second decoders for converting the compressed image data into interlaced first and second image signals, respectively; and the first and second decoders output from the first and second decoders.
A pixel density conversion unit that selects a second image signal, converts and outputs the second image signal into a sequentially scanned image signal, and wherein the mobile-oriented receiving system receives the transmission signal transmitted from the transmission system, A second demodulator for converting the second demodulated signal into a second demodulated signal; a second demodulator for demodulating the second demodulated signal, performing deinterleaving and decoding, and outputting third compressed image data;
A second decoder for decoding the second compressed image data output from the second demodulator and converting it into one interlaced image signal. 3. A receiving system for the fixed station, comprising: a first receiving unit that receives the transmission signal transmitted from the transmission system and converts the transmission signal into a first demodulated signal; and demodulates the first demodulated signal. A first demodulator for performing deinterleaving and decoding and outputting first and second compressed image data and an error detection signal; and the first and second demodulators output from the first demodulator. First and second converting the compressed image data into first and second image signals obtained by interlaced scanning, respectively.
And a first and a second decoder for interpolating the first and second image signals output from the first and second decoder units and outputting two interpolated image signals sequentially scanned. An interpolation unit; a delay unit that outputs a delay control signal obtained by delaying the error detection signal; and a pixel that selects the first and second interpolation image signals based on the delay control signal and converts and outputs the first and second interpolation image signals into a sequentially scanned image signal The image transmission system according to claim 2, further comprising: a density conversion unit. 4. A receiving system for the mobile unit, comprising: a second receiving unit that receives the transmission signal transmitted from the transmission system and converts the transmission signal into a second demodulated signal; and demodulates the second demodulated signal. A second demodulation unit for performing deinterleaving and decoding to output third and fourth compressed image data and an error detection signal; and third and fourth compression units output from the second demodulation unit. Third and fourth decoders for decoding image data and converting them into third and fourth interlaced image signals, respectively; a delay unit for outputting a delay control signal obtained by delaying the error detection signal; 4. The image transmission system according to claim 2, further comprising: a decoder selecting unit that selects and outputs one of the third and fourth image signals according to a delay control signal. 5. A receiving system for the mobile unit, comprising: a second receiving unit that receives the transmission signal transmitted from the transmission system and converts the transmission signal into a second demodulated signal; and demodulates the second demodulated signal. A second demodulation unit that performs deinterleaving and decoding and outputs third and fourth compressed image data and an error detection signal; and a delay unit that outputs a delay control signal obtained by delaying the error detection signal. A decoded signal selection unit for selecting and outputting the third and fourth compressed image data output from the second demodulation unit in accordance with the delay control signal; and decoding the selected and output compressed image data to jump over. 4. The image transmission system according to claim 2, further comprising: a decoder for converting the image into a scanned image signal. 6. The image transmission system according to claim 2, wherein the output of the frame division unit is provided between the frame division unit and the second encoder unit of the transmission system. A thinning unit that receives an interlaced scan image, reduces the number of scan lines, reduces the number of data per scan line, and then outputs the data to the second encoder unit. An interpolation unit that interpolates an image signal output from the second decoder unit and outputs an interpolated image signal to the pixel density conversion unit, between the second decoder unit and the pixel density conversion unit. An image transmission system characterized by having a new image transmission system. 7. The image transmission system according to claim 2, wherein the first and second image signals output from the first and second decoder units included in the fixed-station-side receiving system are interpolated, An image transmission system further comprising an interpolation unit that outputs an interpolated image signal to the pixel density conversion unit.