JPH0686249A - Video digital transmission system and transmitter-receiver therefor - Google Patents

Abstract

PURPOSE:To transmit components which can be received by the receiver of a high resolution corresponding type as well as by even a conventional receiver, at the time of transmitting a high resolution video signal. CONSTITUTION:At a transmission side, the high resolution video signal is separated into high pass components and low pass components (the processing validating range of the conventional receiver), compression-encoded, multiplexed, and transmitted (102, 104, and 105). The edge information of the high pass component side is transmitted (103). At a high resolution reception side, the multiplexed signal is separated, the high pass components and the low pass components are decoded, and synthesized, so that the original high resolution video signal can be obtained (108-111). And also, at the conventional reception side, the low pass components and the edge information are decoded, and synthesized (113-116).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention divides a video signal into a plurality of constituent elements, encodes each constituent element, multiplexes each coded information for transmission, and receives and decodes this transmission signal. The present invention relates to a video digital transmission system and a transmission / reception device thereof.

[0002]

2. Description of the Related Art A video digital transmission system has been developed in which a transmitting side encodes and transmits an image signal and a receiving side decodes the image signal to reproduce an original image signal.

FIG. 9 shows the configuration of a conventional video digital transmitting / receiving apparatus. The video signal input to the terminal 901 is compression-encoded (information source encoding or high-efficiency encoding) in the high-efficiency encoding circuit 902, and after being sufficiently reduced in data rate, sent out to the transmission line 903. On the receiving side, the received signal is decoded by the decoding circuit 904 and supplied to the television receiver 905.

Now, a high-definition television system, for example, an HDTV (High Dinison Television) system has been developed and a system for transmitting and receiving a high resolution video signal has been put into practical use. The high-resolution video signal transmitted by this system cannot be played back by a conventional television receiver. Therefore, when viewing a video on a conventional television receiver, the data rate of the high-resolution video signal, It is necessary to use a converter that converts the number of scanning lines, the aspect ratio, etc. to convert the video signal to the conventional system. It is fully conceivable that a system for compressing and coding and transmitting the high resolution video signal will be developed in the future.

There are the following two possible modes for the viewer to view the high-resolution video signal compression-coded by the above-mentioned video digital transmission system. First, the viewer owns a receiver compatible with high-resolution video signals,
This is a form in which a high-resolution video signal transmitted is decoded by a decoding device and the video is viewed by the receiver. Second, the viewer owns a conventional receiver compatible with video signals, and the transmitted high-resolution video signal is decoded by a decoding device,
Further, the decoded signal is converted into a conventional video signal by a converter and the video is viewed by the conventional receiver.

[0006]

However, in the conventional receiver, the second mode for viewing the image by the above-mentioned high-resolution image signal requires two-step processing. First
The high-resolution video signal decoded in the stage and the high-resolution video signal decoded in the second stage are converted into a conventional video signal. As a result, a viewer who views an image with a conventional receiver is more economically burdened with the converter than a viewer who has a receiver compatible with high resolution. Such a phenomenon hinders widespread use of a system that encodes and transmits / receives a high-resolution video signal.

Therefore, according to the present invention, the encoded high resolution video signal can be transmitted to the receiver compatible with the high resolution video signal, and at the same time, the component that can be received by the conventional receiver as it is is transmitted. It is an object of the present invention to provide a video digital transmission system and a transmission / reception device thereof that can be received by a receiver without going through many signal processing steps.

[0008]

According to the present invention, on the transmitting side, an input video signal is divided into a plurality of constituent elements, and at least one of the constituent elements is within the processing capability range of a conventional receiver. And a means for encoding each of these divided components as an information source and a means for multiplexing each information source encoded output and outputting a multiplexed signal. , Means for decoding the separated output, and means for synthesizing the decoded constituent elements.

Further, as a means for encoding each constituent element as an information source, each constituent element is grouped into at least one constituent element and the other remaining constituent elements, and each constituent element is subjected to the information source coding, and at the same time, the remaining configuration. It is provided with a means for extracting a feature representative of an element and making it the additional information of the at least one component.

[0010]

According to the above means, the video signals divided into a plurality of constituent elements are source coded, multiplexed and sent to the transmission line. Also, on the receiving side, after being demultiplexed, the respective constituent elements are decoded, combined and reproduced as the original video signal. In addition, each component is divided into at least one component and the other remaining components by means of source coding, and each component is source-coded and at the same time, the remaining components are Representative features are extracted and used as additional information of the at least one component. As a result, it is possible to decode and combine all the constituent elements to decode a high resolution video signal. At the same time, by decoding only the at least one constituent element containing a large amount of important information as a video signal, a reception simple resolution decoded video signal within the processing capability range of the conventional receiver can be obtained. At this time, the additional information that is pre-multiplexed serves to improve the quality of the simple resolution decoded video signal on the conventional receiving side.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (Example 1)

FIG. 1 shows a first embodiment of the video digital transmission system of the present invention. Reference numeral 10 is an encoder provided on the transmission side for performing image compression, 20 is a first decoder provided on the reception side for performing image decompression, and 30 is a second decoder.

The high-resolution video signal input to the input terminal 101 is subjected to a high band component and a low band component (including a lot of important information as a video signal by the sub-band division circuit 102,
The signal is band-divided into two sub-band signals (signals within the processing capacity of the conventional receiver). The two divided sub-band signals are supplied to the high band component coding circuit 104 and the low band component coding circuit 105, respectively, and coded to become a high band coded signal and a low band coded signal. The high-frequency subband signal is also input to the edge information extraction circuit 103, where edge information is extracted. A high band and low band encoding circuit 104,
The high band coded signal and the low band coded signal output from 105 are input to the multiplexing circuit 106 and multiplexed with the edge information from the edge information extraction circuit 103. The multiplexed signal obtained by the multiplexing circuit 106 is sent to the transmission line 107. The receiving side will be described.

When a high resolution television receiver is installed, the received multiplexed signal is the demultiplexer circuit 10.
8 is input. The demultiplexing circuit 108 separates the two coded signals, that is, the high band coded signal and the low band coded signal, and supplies them to the high band component decoding circuit 109 and the low band component decoding circuit 110, respectively. High frequency component decoding circuit 109
The high band sub-band signal decoded by the low band component decoding circuit 110 and the low band sub band signal decoded by the low band component decoding circuit 110 are input to the sub band synthesizing circuit 111 to be synthesized and the original high resolution video signal. Restored to. This high resolution video signal is input to the high resolution television receiver 112 and reproduced.

On the other hand, when a simple resolution television receiver (conventional receiver) is installed, the received multiplexed signal is input to the demultiplexing circuit 113. The demultiplexing circuit 113 separates the low band encoded signal and supplies it to the low band component decoding circuit 114, and also separates edge information and supplies it to the enhancer 116. A low-frequency subband signal is derived from the low-frequency component decoding circuit 114 and input to the post filter 115. The post filter 115 reduces aliasing distortion that tends to occur during sub-band division, and then supplies the output to the enhancer 116. Enhancer 11
In 6, the edge information is combined with the low frequency sub-band signal, and the quality is improved by emphasizing the high frequency components. The output of the enhancer 116 is input to the simple resolution television receiver (conventional receiver) 117 and reproduced.

The edge information is, for example, position information of a pixel block consisting of a small number of pixels of a high resolution video signal and a variance value of high frequency components within the pixel block, and these are encoded and other encoded. The signal is multiplexed and transmitted.

FIG. 2 shows a finer block structure of the ender 10 and the first decoder shown in FIG.
The same parts as those in FIG. 1 are designated by the same reference numerals. The subband division circuit 102 on the transmission side includes a low pass filter (LPF) 201 and a subtractor 202 to which a high resolution video signal is supplied.
And the output of the LPF 201 is the low frequency component encoding circuit 10.
5 is supplied. The subtractor 202 subtracts the low-frequency subband signal from the high-resolution video signal to obtain a high-frequency subband signal. The high-frequency subband signal is converted into the high-frequency encoding circuit 1.
04 and the edge information extraction circuit 103. The subsequent steps are the same as those described with reference to FIG.

On the receiving side, the subband synthesis circuit 111 of the first decoder 20 is shown in detail. The outputs of the high-frequency component decoding circuit 109 and the low-frequency component decoding circuit 110 are input to the adder 210, synthesized and restored to a high-resolution video signal, and supplied to one of the switches 213. The output of the low-frequency component decoding circuit 110 is input to the LPF 211 to remove the aliasing component, and then the enhancer 2
The high frequency component is emphasized by being input to 12 and added with edge information, and is supplied to the other of the switches 213 as a simple resolution video signal. The switch 213 is
Depending on the viewer's selection, either the high resolution video signal or the simple resolution video signal is selected and derived as a reproduction video signal. If you own this first decoder 20,
It can be used for both a high-resolution video signal compatible receiver and a simple resolution video signal compatible receiver (conventional receiver). The blocks of the second decoder 30 are the same as those shown in FIG. 1 and are dedicated to the conventional receiver. (Example 2)

FIG. 3 shows an encoder 10 according to the second embodiment of the present invention. Corresponding first and second decoders are shown in FIG. The same functional parts as those of the previous embodiment are designated by the same reference numerals. The high-resolution video signal introduced to the input terminal 101 is the subband division circuit 1
In 02, the signal is downsampled to 2: 1 and input to the high-pass filter 301 and the low-pass filter 302. The high band sub-band signal obtained from the high pass filter 301 is
High frequency component encoding circuit 104, edge information extraction circuit 103
The low-pass subband signal input to the low-pass filter 302 is input to the low-pass component coding circuit 105. The high frequency encoded output obtained from the high frequency component encoding circuit 104 is input to the scrambler 303, subjected to scramble processing, and then supplied to the multiplexing circuit 106. In the multiplexing circuit 106, the scrambled high frequency encoded output, the low frequency encoded output from the low frequency component encoding circuit 105, the edge information, and the descrambling information from the pay descrambling information generator 304. Are multiplexed and transmitted as a multiplexed signal to the transmission path.

The decoder of FIG. 4 will be described. The received multiplexed signal is introduced into the demultiplexing circuits 108 and 113. In the demultiplexing circuit 108, the high frequency encoded signal,
The low-frequency coded signal and pay descrambling information are separated. Since the high frequency encoded signal has been scrambled, the descrambler 401 descrambles it. The scrambled high frequency encoded signal is input to the high frequency component decoding circuit 109 to be decoded. Further, the low frequency component decoding circuit 110 receives and decodes the low frequency component encoded signal. Decoding circuit 109, 11
Each decoded output of 0 is the subband synthesis circuit 11
1 high-pass filter 402, low-pass filter 403
Entered in. In the high-pass filter 402 and the low-pass filter 403, interpolation (upsampling) is performed so that distortion due to aliasing does not occur, and the original subband signal is reproduced. The high band and low band sub-band signals are input to the adder 402, restored to a high resolution video signal, and supplied to one of the switches 213. Further, the low-frequency subband signal from the low-pass filter 403 is the LP
After being input to F211 to remove the aliasing component, it is input to the enhancer 212 and edge information is added to emphasize the high frequency component, and is supplied to the other of the switches 213 as a simple resolution video signal. As described with reference to FIG. 2, the switch 213 selects one of them according to the operation of the viewer and derives it as a reproduced video signal.

In the second decoder, the demultiplexing circuit 113 separates the low band coded signal and the edge information.
Since the low-frequency encoded signal has not been scrambled, it is directly input to the low-frequency component decoding circuit 114 and decoded. The decoded output is interpolated (upsampled) by the low-pass filter 404 so that distortion due to aliasing does not occur, and is reproduced as the original low-pass subband signal. After that, as in the previous embodiment, the LPF 11
5, passed through the enhancer 116 and derived as a reproduced video signal of simple resolution. (Example 3)

FIGS. 5 and 6 show still another embodiment of the present invention. FIG. 5 shows an encoder and FIG. 6 shows a decoder. In this embodiment, the transmission side divides the high-resolution video signal into a larger number of frequency regions (two-dimensional frequency regions) to create a plurality of components, and each component is coded and compressed, and coded. The output is multiplexed and transmitted, and at the receiving side, each encoded output is separated from the multiplexed signal,
Each of them is decoded to reproduce the original constituent elements, and these constituent elements are combined.

The high-resolution video signal introduced to the input terminal 601 is horizontally divided into two bands by the horizontal high-pass filter 602 and the horizontal low-pass filter 603 and down-sampled to 2: 1. The sub-band signal obtained from the horizontal high pass filter 602 is further processed by the vertical high pass filter 604 and the vertical low pass filter 60.
5 is input, further divided, and subsampled 2: 1. Further, the sub-band signal obtained from the horizontal low pass filter 603 is also added to the vertical high pass filter 60.
6, input to the vertical low pass filter 607, further divided, and sub-sampled 2: 1. As a result, the input high-resolution video signal has four spatial frequency domain 4
This means that the sub-band signals HH, HL, LH, and LL are divided.

The sub-band signals HH, HL and LH are input to the quantizing circuits 608, 609 and 610 respectively and quantized, and the sub-band signal LL is input to the DCT (discrete cosine transform) circuit 614 and the frequency domain components ( DCT
Coefficient). In addition, the subband signals HH and H
L and LH are edge information extraction circuits 611 and 61, respectively.
It is also input to 2, 613. The DCT coefficient obtained from the DCT circuit 614 is input to the quantization circuit 615 and quantized.

Quantization circuits 608, 609, 610, 61
The respective quantized outputs outputted from No. 5 are inputted to the variable length coding circuits 616, 617, 618 and 619 and variable length coded. Each encoded output is further input to buffer circuits 620, 621, 622, 623. The outputs of the buffer circuits 620, 621 and 622 are scrambled by scramblers 624, 625 and 626, respectively, and input to the multiplexing circuit 628. The output of the buffer circuit 623 is directly input to the multiplexing circuit 628. The descramble information from the descramble information generator 627 and the edge information EHH, EHL, and ELH from the edge information extraction circuits 611, 612, and 613 are further input to the multiplexing circuit 628. The multiplexing circuit 628 multiplexes these input information, creates a multiplexed signal, and sends it to the transmission path.

In FIG. 6, a multiplexed signal that has passed through the transmission path is introduced into the input terminal 702. The multiplexed signal is input to the demultiplexing circuit 702. In the demultiplexing circuit 702, the encoded sub-band signals HH, HL, LH, LL.
Are separated, and descrambling information, edge information, etc. are also separated. The horizontal and vertical high-frequency coded subband signals are descrambled by the descrambler 703, and the horizontal high-vertical low-frequency coded subband signals are descrambled by the descrambler 703. The descrambler 703 descrambles the vertical sub-band encoded sub-band signal. The coded subband signal in the horizontal low band and the vertical low band is directly input to the inverse quantization circuit 706 because the scramble processing is not performed.

The coded subband signals descrambled by the descramblers 703, 704 and 705 are input to dequantization circuits 707, 708 and 709, respectively, and dequantized. The dequantized output dequantized by the dequantizing circuit 706 is input to the inverse DCT circuit 710.

The dequantized output from the dequantization circuit 707 is input to the high pass filter 711, is interpolated (upsampled) so as not to cause aliasing distortion, and is input to the adder 715 to be dequantized. The dequantized output from the circuit 708 is input to the low pass filter 712, is interpolated (upsampled) so as not to cause aliasing distortion, and is input to the adder 715. As a result, the adder 71
From 5, the same signal as the output of the high-pass filter 602 on the decoder side is reproduced.

The dequantized output from the dequantization circuit 709 is input to the high-pass filter 713, is interpolated (upsampled) so as not to cause aliasing distortion, and is input to the adder 716 to be dequantized. The dequantized output from the circuit 710 is input to the low-pass filter 714, interpolated (upsampled) so as not to cause aliasing distortion, and input to the adder 716. As a result, the adder 71
From 6, the same signal as the output of the high-pass filter 603 on the decoder side is reproduced.

Further, the output of the adder 715 is input to the horizontal high-pass filter 717 and is interpolated (upsampled) in the horizontal direction, and the output of the adder 716 is input to the horizontal low-pass filter 718 and is output in the horizontal direction. Is interpolated (upsampled). Then, the outputs of the horizontal high-pass filter 717 and the horizontal low-pass filter 718 are added by the adder 720 to reproduce the original high resolution video signal.

The above description has been that of a high resolution video signal decoder for a viewer who owns a high resolution television receiver. However, as a decoder for a viewer who owns a simple resolution television receiver, it is sufficient that the demultiplexing circuit 702 separates the encoded subband signal LL and the edge information. The encoded sub-band signal LL has an inverse quantization circuit 706a,
The inverse DCT circuit 710a and the low-pass filter 714a sequentially process and decode, and input to the enhancer 721 via the post filter 719. Enhancer 72
In No. 1, edge information EHH, EHL, and ELH are added to enhance the high frequency component, quality is improved, and the signal is derived as a signal for a simple resolution television receiver.

Further, when the viewer wants to use both the high resolution television receiver and the simple resolution television receiver, this decoder is provided with a post filter 719 and an enhancer in addition to the decoder portion for the high resolution video signal. Only 721 and switch 722 need be added. In this case, the inverse quantization circuit 706a, the inverse DCT circuit 710a, and the low pass filter 714a may be omitted.

The viewer causes the switch 722 to select the output of the adder 720 when using a high resolution video signal,
When the simple resolution video signal is used, the switch 722 may select the output of the enhancer 721.

FIG. 7 shows the enhancer 11 of the first and second embodiments.
6 is a specific example. The video signal input from the input terminal 811 is a high pass filter or band pass filter 81.
2 and the adder 814 and the switch 81.
5 is input to one terminal b. The high frequency components derived from the filter 812 are gain-adjusted by the gain adjuster 813 and input to the adder 814. As a result, the filter 81
A signal emphasizing the pass band component of 2 is obtained from the adder 814 and supplied to the other terminal a of the switch 815. The edge information separated by the demultiplexing circuit is input to the input terminal 816. This edge information is used as the variance value determiner 817.
Entered in. The edge information is, for example, position information of a pixel block including a small number of pixels of the video signal and a variance value of high frequency components in the pixel block. Variance value determiner 817
Controls so that the switch 815 selects the emphasized signal that is the output of the adder 814 when the variance value is large to some extent, and the input terminal 811 when the variance value is small.
Is controlled by the switch 815.

The present invention is not limited to the above-described respective embodiments. For example, in the third embodiment, the subband signals are coded in the two-dimensional frequency domain and the spatial frequency domain is divided into four domains. An example of division is shown. However, the present invention is not limited to this, and the band division may be 4 or less or 4 or more. When the division band is set to 4 or more, it is only necessary to repeatedly perform filtering and thinning (subsampling) hierarchically on the signal in each region as shown in FIG. 8A. That is, the horizontal high-pass and low-pass filter 81
Horizontal frequency separation is performed by means of 1 and 812, and sub-sampling is performed by thinning circuits 813 and 814, respectively. Next, the output of the thinning circuit 813 is subjected to vertical frequency separation by the vertical high-pass and low-pass filters 815 and 816, and the thinning circuits 817 and 818 subsample each. Similarly, the output of the thinning circuit 814 is also
Vertical high frequency and low pass filters 819 and 820 perform vertical frequency separation, and thinning circuits 821 and 82 respectively
2 is sub-sampled. In the case of further division, each output of the thinning circuits 817 to 822 may be separated in horizontal frequency. FIG. 8B shows bands of signal components obtained from the thinning circuits 817 to 822.

According to each of the above-described embodiments, the high-resolution video signal is coded by synthesizing all the frequency band signals by the expensive receiver on the receiver side, or it is important as an image by the inexpensive receiver. Obtain a simple video signal by decoding only the signal in the frequency band containing a lot of information
Alternatively, an expensive receiver can freely select whether to obtain a high-resolution video signal or a simple video signal. According to the system of this embodiment, in the coming multi-channel transmission and pay broadcasting eras, it is possible to provide an effective broadcasting service that meets the needs of viewers and a transmitting / receiving device that can support it without increasing the number of transmission channels. In particular, when the receiver is for a current television signal and the signal to be transmitted is a high resolution television signal, after decoding all the high resolution video signal once, it is converted into the current television signal. There is no need for double labor such as doing. It suffices to directly decode a specific component (subband signal). At this time, the post filter (LP
After the aliasing distortion is reduced by F), the enhancement is performed based on the edge information that is multiplexed in advance.
There is no problem that the image quality of the simple video signal is bad.

[0037]

As described above, according to the present invention,
The encoded high resolution video signal can be transmitted to the receiver compatible with the high resolution video signal, and at the same time, the component that the conventional receiver can directly receive can be transmitted and received.

[Brief description of drawings]

FIG. 1 is a block diagram showing a transmission side (encoder) and a reception side (decoder) in an embodiment of the present invention.

FIG. 2 is a block diagram showing a part of FIG. 1 in more detail.

FIG. 3 is a block diagram showing an encoder of another embodiment of the present invention.

FIG. 4 is a block diagram showing a decoder corresponding to the encoder of FIG.

FIG. 5 is a block diagram showing an encoder of still another embodiment of the present invention.

6 is a block diagram showing a decoder corresponding to the encoder of FIG.

FIG. 7 is a diagram showing a configuration example of an enhancer.

FIG. 8 is a block diagram showing an example of generating a subband signal.

FIG. 9 is a block diagram showing a conventional high efficiency encoding and decoding system.

[Explanation of symbols]

102 ... Subband division circuit, 103 ... Edge information extraction circuit, 104 ... High-frequency component coding circuit, 105 ... Low-frequency component coding circuit, 106 ... Multiplexing circuit, 107 ... Transmission path, 1
06 ... demultiplexing circuit, 109 ... high-frequency component decoding circuit, 1
10 ... Low-frequency component decoding circuit, 111 ... Sub-band synthesis circuit, 112 ... High-resolution television signal receiver, 113
... demultiplexing circuit, 114 ... low-frequency component decoding circuit, 115
... post filter, 116 ... enhancer, 117 ... simple resolution television signal receiver, 201 ... low-pass filter, 202 ... subtractor, 210 ... adder. 211 ... Low-pass filter, 212 ... Enhancer, 213 ... Switch, 301 ... High-pass filter, 302 ... Low-pass filter, 303 ... Scrambler, 304 ... Descramble information generator, 401 ... Descrambler, 402 ... High Low-pass filter, 403 ... Low-pass filter, 404 ... Low-pass filter.

Claims (12)

[Claims] 1. A video digital transmission method for transmitting a video signal by encoding it as an information source, wherein a transmitting side divides an input video signal into a plurality of constituent elements,
For at least one of the constituent elements, means for setting the processing capacity range of a conventional receiver, means for respectively encoding the plurality of divided constituent elements with each other, and multiplexing with each information source encoded output And a means for outputting the multiplexed signal, and a receiving side comprising means for separating the received multiplexed signal, means for decoding the separated output, and means for synthesizing the decoded constituent elements. Video digital transmission method characterized by 2. The means for dividing into the plurality of constituent elements comprises:
2. The video digital transmission system according to claim 1, further comprising means for dividing the input video signal into a plurality of frequency components (hereinafter referred to as subband signals). 3. Means for source-encoding each of the plurality of components is grouped into the at least one component and the other remaining components, and each component is source-encoded at the same time. 2. The video digital transmission system according to claim 1, wherein a characteristic representing the remaining constituent elements is extracted and used as additional information of the at least one constituent element. 4. The video digital transmission system according to claim 2, wherein the means for multiplexing the plurality of information source coded outputs allocates a transmission capacity according to the amount of information generated in each subband. 5. The video digital transmission system according to claim 1, wherein at least one subband signal is subjected to an encryption process when the coded outputs of the respective information sources are multiplexed. 6. The input video signal is divided into a plurality of constituent elements,
At least one of the constituent elements is a means for setting a processing capacity range of a conventional receiver, means for encoding each of these constituent elements as an information source, and each information source encoded output is multiplexed and sent to a transmission line. An image digital transmitting apparatus comprising: 7. The video digital transmitting apparatus according to claim 6, wherein the means for dividing the plurality of constituent elements is a filter group for dividing the video signal into subband signals. 8. The source coding of each of the sub-band signals is performed, at the same time, a feature representative of a high-frequency sub-band signal is extracted, and the features are multiplexed and sent to the transmission path. 7. The digital video transmission device according to 7. 9. The characteristic representing the high frequency sub-band signal is a dispersion value of each sub-band signal in a plurality of pixel blocks of the video signal, and a position of the pixel block and a code indicating the dispersion value are multiplexed. 9. The video digital transmission device according to claim 8, wherein the video digital transmission is performed after being converted. 10. The received multiplexed signal divides a video signal into a plurality of constituent elements, and at least one of the constituent elements falls within a processing range of a conventional receiver, and the plurality of divided constituents are provided. Each element is information source coded, and each information source coded output is multiplexed. Means for separating the received multiplexed signal for each multiplexed component and their respective separated outputs And a means for synthesizing the respective decoded outputs, and a video digital receiving apparatus. 11. The plurality of constituent elements are divided in a frequency domain, at least one of the constituent elements is a component in a low frequency range, and the plurality of constituent elements are the remaining constituent elements. The means for decoding each of the decoded outputs also decodes the edge information, and the means for synthesizing each of the decoded outputs is a component of the low frequency domain. A video digital receiving apparatus, characterized in that the decoded edge information is combined with a decoded output. 12. The received multiplexed signal is obtained by dividing a video signal in a frequency domain into a plurality of components, at least one of which is within a processing range of a conventional receiver. The components obtained by extracting the characteristics of the remaining constituent elements are used as edge information, and the plurality of divided constituent elements and the edge information are each information source coded, and each information source coding output is multiplexed. A means for separating only the encoded component corresponding to the component in the low frequency region and the encoded component of the edge information from the received multiplexed signal, and means for decoding the respective separated outputs. And a means for synthesizing the respective decoded outputs, a video digital receiving apparatus.