JP3598159B2 - Information signal transmission device and information signal transmission method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an information signal transmission apparatus suitable for application to an interactive digital broadcasting system or the like. And information signal transmission method About. More specifically, an information signal is compressed by a plurality of different coding methods to obtain a coded signal, and an optimum coded signal is selected from the obtained coded signals, and information is added to the selected coded signal. By transmitting with the addition of, for example, an image can be transmitted with high compression and high image quality.
[0002]
[Prior art]
With the development of digital technology, an interactive integrated digital broadcasting system (referred to as ISDB (Integrated Services Digital Broadcasting) system) that digitizes various kinds of information including broadcast signals has been researched and developed in the broadcasting world.
[0003]
More specifically, the ISDB system is used to transmit current broadcast signals (standard television signals, high-definition signals), data such as software and facsimile, and multimedia information such as voice, text, graphics, and images. This is a broadcasting system that digitizes (encodes) each, integrates and multiplexes them, performs modulation processing that matches the transmission mode, and transmits them.
[0004]
In the case where various information including a broadcast signal is integrated and multiplexed, additional information used as control information on the receiving side can be simultaneously multiplexed and transmitted in addition to the information. The integrated ISDB broadcast signal (digital signal) is transmitted using a terrestrial wave, a satellite wave, an optical cable, or the like.
[0005]
The receiving terminal receives the integrated ISDB broadcast signal, discriminates the target signal, displays it on a monitor, and enjoys it as a normal television broadcast. (Save) or transfer to another terminal. Further, if the received additional information is used, the received information can be used according to the user's preference, such as monitor control, recording control, and processing control on the monitored image. That is, an interactive broadcasting system can be constructed.
[0006]
Therefore, if this ISDB system is used, the more and more types of additional information to be transmitted, the better the service contents to the user, and a more interactive broadcasting system can be constructed.
[0007]
[Problems to be solved by the invention]
By the way, in an information signal transmission device for transmitting such an ISDB broadcast signal or the like, for example, an image signal is compressed by one predetermined method and multiplexed with another signal before being transmitted. For this reason, even for an image for which optimal compression cannot be performed by one of the predetermined methods, compression is performed by this method, resulting in a decrease in compression efficiency and a deterioration in image quality of a transmission image.
[0008]
Therefore, the present invention provides an information signal transmission device capable of transmitting an information signal with high compression and high quality. And information signal transmission method Is provided.
[0009]
[Means for Solving the Problems]
An information signal transmission device according to the present invention divides an information signal on one screen into fixed blocks, compresses the information signals of the divided blocks by a plurality of different encoding methods, and generates a compressed signal of each encoding method. Encoding means for obtaining Data amount calculation means for calculating the data amount of each of the plurality of compressed signals corresponding to the information signal of the block obtained by the coding means, and a plurality of compressed signals corresponding to the information signal of the block obtained by the coding means Decoding means to respectively expand the, the deviation amount calculating means to calculate the deviation amount between the information signal and each expanded signal obtained by the decoding means, Signal selecting means for selecting one signal from a plurality of compressed signals corresponding to the information signal of the block, and data transmitting means for adding information to the compressed signal corresponding to the information signal of the block selected by the signal selecting means for transmission And having The signal selecting means selects one signal from the plurality of compressed signals based on an evaluation value obtained by adding the weighting result of the data amount and the weighting result of the deviation amount in each of the plurality of encoding schemes. Things.
[0011]
An information signal transmission method according to the present invention divides an information signal on one screen into fixed blocks, compresses the information signals of the divided blocks by a plurality of different encoding schemes, and generates a compressed signal of each encoding scheme. Get Encoding procedure and , A data amount calculation procedure for calculating a data amount of each of the plurality of compressed signals corresponding to the information signal of the block obtained by the encoding procedure, and a plurality of compressed signals corresponding to the information signal of the block obtained by the encoding procedure A decoding procedure for decompressing the information signal, a deviation calculation procedure for calculating a deviation between the information signal and each decompressed signal obtained in the decoding procedure, Select one signal from multiple compressed signals corresponding to the block information signal Signal selection procedure , Selected in the signal selection procedure Adds information to the compressed signal corresponding to the information signal of the block and transmits it And a data transmission procedure. In the signal selection procedure, one signal is selected from a plurality of compressed signals based on an evaluation value obtained by adding a result of weighting the amount of data and a result of weighting the amount of deviation in each of the plurality of encoding schemes. Things.
[0013]
According to the present invention, since the encoding method that provides good compression efficiency and reduces the amount of deviation differs depending on the information signal, the information signal is subjected to compression / expansion processing using a plurality of encoding methods, and the data amount or the compression amount after the compression processing is increased. A compressed signal of an optimal encoding method is selected based on a deviation amount generated by the decompression process. Further, information indicating the encoding method is added to the selected compressed signal and transmitted.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of an information signal transmission device according to the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a diagram illustrating a configuration of an information signal transmission device that transmits, for example, an image signal as an information signal. In FIG. 1 showing the configuration of the first embodiment of the information signal transmission device, an analog image signal VS is supplied to an A / D converter 11 of the information signal transmission device 10. In the A / D converter 11, the image signal VS is converted into a digital image data signal DS having a predetermined number of bits, and is supplied to the blocking unit 12 and the image memory 13.
[0016]
In the blocking unit 12, the pixel data of the image data signal DS corresponding to a predetermined number of pixels on the screen is blocked and supplied to the coding units 21 and 31 as a blocked signal BD.
[0017]
The encoding unit 21 performs, for example, a discrete cosine transform (hereinafter referred to as “DCT”) for each block of the blocked signal BD, and quantizes and encodes the obtained DCT coefficients to obtain the blocked signal BD. Is performed. The compressed image data signal CA, which is a signal obtained by compressing the block signal BD, is supplied to the information amount calculation unit 22 and the image memory unit 23.
[0018]
The information amount calculator 22 calculates the data amount of the compressed image data signal CA for each block. The calculation signal IA indicating the calculation result is supplied to a signal selection processing unit 16 described later. The image memory 23 stores the compressed image data signal CA.
[0019]
The compressed image data signal CA stored in the image memory unit 23 is read and supplied to the decoder unit 24. In the decoder unit 24, decoding, inverse quantization, and inverse discrete cosine transform (IDCT) are performed on the compressed image data signal CA, and decompression processing of the compressed image data signal CA is performed. The expanded data signal EA obtained by this expansion process is stored in the image memory 25.
[0020]
Further, the encoding unit 31 performs data compression processing for each block of the blocked signal BD, for example, by high-efficiency encoding (hereinafter, referred to as “ADRC (Adaptive Dynamic Range Coding) encoding”) adapted to a dynamic range.
[0021]
Here, the ADRC encoding will be described with reference to FIG. FIG. 2 is a diagram showing a configuration of the encoding unit 31 which is an ADRC encoding unit. 2, the blocked signal BD is supplied to a maximum value detection unit 41, a minimum value detection unit 42, and a delay unit 43. The maximum value detection unit 41 detects the maximum value MX of one block of the block signal BD. The minimum value detection unit 42 detects the minimum value MN of one block of the block signal BD. In the delay unit 43, the blocked signal BD is delayed until the minimum value MN is detected by the minimum value detection unit 42.
[0022]
The maximum value MX detected by the maximum value detection unit 41 is supplied to the subtraction unit 44. The minimum value MN detected by the minimum value detection unit 42 is supplied to the subtraction units 44 and 45 and the multiplexer unit 47. Further, the delayed blocked signal BDD from the delay unit 43 is supplied to the subtraction unit 45.
[0023]
The subtractor 44 subtracts the minimum value MN from the maximum value MX to calculate the dynamic range DR. This dynamic range DR is supplied to the quantization unit 46 and the multiplexer unit 47. Further, the subtractor 45 subtracts the minimum value MN from the delayed block signal BDD, and supplies the subtraction data signal SDD to the quantizer 46.
[0024]
In the quantization unit 46, a quantization step width is set based on the supplied dynamic range DR, and the subtraction data signal SDD is quantized with the set quantization step width to generate a quantization signal TDD. For example, the quantization bit number of one pixel is compressed from 8 bits to 4 bits to generate a quantization signal TDD. This quantized signal TDD is supplied to the multiplexer unit 47. In the multiplexer unit 47, a compressed image data signal CB is generated from the supplied dynamic range DR, minimum value MN, and quantized signal TDD.
[0025]
Thus, the compressed image data signal CB, which is a compressed signal of the block signal BD generated by the encoding unit 31, is supplied to the information amount calculation unit 32 and the image memory unit 33 shown in FIG.
[0026]
The information amount calculation unit 32 calculates the data amount of the compressed image data signal CB for each block. The calculation signal IB indicating the calculation result is supplied to a signal selection processing unit 16 described later. In the image memory 33, the compressed image data signal CB is stored.
[0027]
The compressed image data signal CB stored in the image memory unit 33 is read and supplied to the decoder unit 34.
[0028]
Here, the configuration of the decoder section 34 is shown in FIG. The compressed image data signal CB is supplied to the demultiplexer 51, where it is separated into a dynamic range DR, a minimum value MN, and a quantized signal TDD. The dynamic range DR and the quantized signal TDD are supplied to the inverse quantization unit 52. Further, the minimum value MN is supplied to the adding unit 53.
[0029]
In the inverse quantization unit 52, a step width of the inverse quantization is set based on the supplied dynamic range DR. Further, the quantized signal TDD is inversely quantized based on the set step width to generate a signal UDD. This signal UDD is supplied to the adder 53.
[0030]
The adder 53 adds the signal UDD and the minimum value MN to generate an expanded data signal EB. This expanded data signal EB is stored in the image memory unit 35 shown in FIG.
[0031]
The decompressed data signal EA stored in the image memory 25 and the decompressed data signal EB stored in the image memory 35 are read and supplied to the deviation calculator 15.
[0032]
The deviation amount calculator 15 calculates the deviation amount of the data of the expanded data signal EA with respect to the data of the image data signal MVD read from the image memory unit 13 for each block. The calculation signal SA indicating the calculation result is supplied to the signal selection processing unit 16. Similarly, the amount of deviation of the data of the decompressed data signal EB with respect to the data of the image data signal MVD is calculated for each block, and a calculation signal SB indicating the calculation result is supplied to the signal selection processing unit 16.
[0033]
The signal selection processing unit 16 generates a switching control signal SC for the signal switch 17 based on the calculation signals SA and SB and the calculation signals IA and IB supplied from the information amount calculation units 22 and 32. For example, the evaluation value VA calculated by the expression (1) is compared with the evaluation value VB calculated by the expression (2), and when the condition of the expression (3) is satisfied, the movable terminal 17c of the signal switch 17 is switched The compressed image data signal CA stored in the image memory unit 23 is selected as the terminal 17a side, and if the condition is not satisfied, the compressed image data signal stored in the image memory unit 33 with the movable terminal 17c as the terminal 17b side A switching control signal SC for selecting CB is generated. Note that “α” and “β” in the expressions (1) and (2) are constants.
[0034]
VA = α × IA + β × SA (1)
VB = α × IB + β × SB (2)
VA ≦ VB (3)
The switching control signal SC is supplied to the signal switch 17 and the signal multiplexing unit 18. The terminals 17a and 17b of the signal switch 17 are supplied with compressed image data signals CA and CB from the image memory units 23 and 33, respectively, and based on the switching control signal SC, any of the compressed image data signals CA and CB is provided. These signals are selected and supplied to the signal multiplexing unit 18.
[0035]
The signal multiplexing unit 18 is supplied with a compressed audio data signal AU from an audio signal encoding device (not shown), and multiplexes based on the compressed image data signal and the compressed audio data signal AU supplied from the signal switch 17. A signal MS is generated. The multiplexed signal MS indicates whether the compressed image data signal is the compressed image data signal CA read from the image memory unit 23 or the compressed image data signal CB read from the image memory unit 33. Information to be determined is added based on the switching control signal SC.
[0036]
Next, the operation will be described with reference to FIG. FIG. 4 shows a display image based on the image signal VS. For example, the pixel data of the image data signal DS corresponding to the area D1 of the display image is one block.
[0037]
The encoding unit 21 performs compression processing on the data in the area D1 based on the blocked signal BD, and the information amount calculation unit 22 calculates the data amount after compression. The data compressed by the encoding unit 21 is expanded by the decoder unit 24 and stored in the image memory unit 25. Similarly, the data compression process is performed by the encoding unit 31, the data amount is calculated by the information amount calculation unit 32, and the compressed data is decompressed by the decoder unit 34 and stored in the image memory unit 35. You.
[0038]
The deviation amount calculation unit 15 calculates the deviation amount between the pixel data of the area D1 stored in the image memory unit 13 and the compressed and expanded pixel data of the area D1 stored in the image memory units 25 and 35. You.
[0039]
Here, for example, when the spatial frequency of the image in the region D1 is high, the data amount after the compression processing in the encoding unit 21 using DCT is the data amount after the compression processing in the encoding unit 31 using ADRC. It is assumed to be larger than the quantity. At this time, assuming that the deviation amount between the pixel data stored in the image memory unit 13 and the pixel data stored in the image memory units 25 and 35 is substantially equal, the deviation is calculated by Expressions (1) and (2). The evaluated values VA and VB do not satisfy the condition of Expression (3). For this reason, the movable terminal 17c of the signal switch 17 is set to the terminal 17b side based on the switching control signal SC, so that the compressed image data signal CB which is the data of the area D1 subjected to the compression processing by the encoding unit 31 is selected. The signal is supplied to the signal multiplexing unit 18.
[0040]
The signal multiplexing unit 18 generates a multiplexed signal MS having a configuration as shown in FIG. 5, for example, from the compressed image data signal CB, the compressed audio data signal AU, and the switching control signal SC. In FIG. 5, in the compressed information signal, based on the switching control signal SC, the compressed image data signal is the compressed image data signal CA from the encoder 21 using DCT, or from the encoding unit 31 using ADRC. It indicates whether the signal is the compressed image data signal CB. It should be noted that headers A, B, and C for identifying the respective signals are added to the compressed information signal, the compressed image data signal, and the compressed audio data signal.
[0041]
Next, the image data signal DS corresponding to the region D2 of the display image is made into one block, and the same processing as that of the above-described region D1 is performed, and the evaluation calculated by the expressions (1) and (2) is performed. If the values VA and VB satisfy the condition of the equation (3), the movable terminal 17c of the signal switch 17 is set to the terminal 17a side based on the switching control signal SC. The compressed image data signal CA, which is data of the region D2, is selected, and a multiplexed signal MS is generated.
[0042]
Thereafter, the same processing is performed on all the areas on one screen, and a compressed image data signal of an encoding method with a small data amount and small deviation amount is selected for each block to generate a multiplexed signal MS. .
[0043]
As described above, in the above-described first embodiment, data is compressed for each block by a different compression method, and the amount of data after compression and the amount of deviation after compression / expansion of a signal before compression are calculated. Thus, a compressed image data signal of an encoding method with a small data amount and small deviation amount is selected and transmitted. Therefore, an image signal can be transmitted with high compression and high image quality. Also, since the transmitted compressed image data signal is added with compression information indicating which encoding method was used to compress the data, the receiving side can easily decompress the compressed image data signal based on this information. It can be performed.
[0044]
In the above-described first embodiment, the image signal is compressed by the block coding method for compressing data for each block. However, the image signal is not limited to the block coding method and may be compressed by using another coding method. The signal may be compressed.
[0045]
Next, as a second embodiment of the information signal transmission apparatus according to the present invention, an information transmission apparatus using an encoding system other than the block encoding system will be described with reference to FIG. FIG. 6 is a diagram showing the configuration of the second embodiment, in which parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0046]
6, the image data signal DS output from the A / D converter 11 is supplied to the blocking unit 12, the image memory unit 13, and the encoding unit 61.
[0047]
The encoding unit 61 performs predictive encoding on the image data signal DS by, for example, DPCM (Differential Pulse Code Modulation), and compresses the image data signal DS. The compressed image data signal CC, which is a compressed signal of the image data signal DS, is supplied to the information amount calculation unit 62 and to the image memory unit 63.
[0048]
The information amount calculation unit 62 calculates the data amount of the compressed image data signal CC corresponding to the line blocked by the blocking unit 12. For example, when one screen image is 480 lines × 720 pixels and one block is 8 lines × 8 pixels, the data amount of the compressed image data signal CC for 8 lines, that is, 8 lines × 720 pixels The data amount of the corresponding compressed image data signal CC is calculated. The calculation signal IC indicating the calculation result is supplied to a signal selection processing unit 72 described later. Similarly, in the image memory unit 63, the compressed image data signal CC corresponding to the line blocked by the blocking unit 12 is stored.
[0049]
The compressed image data signal CC stored in the image memory unit 63 is read out and supplied to the decoder unit 64. In the decoder unit 64, decoding, inverse quantization, and the like are performed on the compressed image data signal CC, and expansion processing of the compressed image data signal CC is performed. The expanded data signal EC obtained by this expansion process is stored in the image memory 65.
[0050]
Note that the information amount calculator 22b corresponding to the information amount calculator 22 shown in FIG. 1 calculates the data amount of the compressed image data signal CA corresponding to the pixel whose data amount has been calculated by the information amount calculator 62. That is, when one block is 8 lines × 8 pixels and the information amount calculation unit 62 calculates the data amount of the compressed image data signal CC corresponding to 8 lines × 720 pixels, 90 blocks of the compressed image data signal CA Is calculated. The calculation signal ID indicating the calculation result is supplied to a signal selection processing unit 72 described later. The image memory unit 25b stores an expanded data signal EA of the compressed image data signal CA of 90 blocks.
[0051]
The deviation amount calculation unit 71 calculates the deviation amount of the data of the expanded data signal EA with respect to the data of the image data signal MVD read from the image memory unit 13. The calculation signal SD indicating the calculation result is supplied to the signal selection processing unit 72. Similarly, the amount of deviation of the data of the decompressed data signal EC with respect to the image data signal MVD is calculated, and a calculation signal SC indicating the calculation result is supplied to the signal selection processing unit 72.
[0052]
The signal selection processing unit 72 generates a switching control signal SC for the signal switch 17 based on the calculation signals SC and SD and the calculation signals IC and ID supplied from the information amount calculation units 22b and 62. For example, the evaluation value VC calculated by Expression (4) is compared with the evaluation value VD calculated by Expression (5), and when the condition of Expression (6) is satisfied, the movable terminal 17c of the signal switch 17 is switched. When the compressed image data signal CA is selected as the terminal 17a and the condition is not satisfied, the switching control signal SC is generated to select the compressed image data signal CB with the movable terminal 17c as the terminal 17b. Note that “m” and “n” in the expressions (4) and (5) are constants.
[0053]
VC = m × IC + n × SC (4)
VD = m × ID + n × SD (5)
VC ≦ VD (6)
The switching control signal SC thus generated is supplied to the signal switch 17 and the signal multiplexing unit 18. The terminals 17a and 17b of the signal switch 17 are supplied with compressed image data signals CA and CC from the image memory units 23 and 63, respectively. These signals are selected and supplied to the signal multiplexing unit 18.
[0054]
The signal multiplexing unit 18 is supplied with a compressed audio data signal AU from an audio signal encoding device (not shown), and based on the read data signal supplied from the signal switch 17 and the compressed audio data signal AU, a multiplexed signal. An MS is generated. The multiplexed signal MS contains information for determining whether the compressed image data signal is the compressed image data signal CA read from the image memory unit 23 or the compressed image data signal CC read from the image memory unit 63. It is added based on the switching control signal SC.
[0055]
Next, the operation will be described with reference to FIG. FIG. 7 shows a display image based on the image signal VS. The image data signal DS corresponding to, for example, the area D1 of the display image is one block.
[0056]
The encoding unit 21 compresses the data in the regions D1 to Dn for each block based on the blocked signal BD, and adds the compressed data amount of the regions D1 to Dn in the information amount calculation unit 22. The data in the areas D1 to Dn compressed by the encoding unit 21 is expanded by the decoder unit 24 and stored in the image memory unit 25b.
[0057]
The encoding unit 61 compresses the data of the areas D1 to Dn, and calculates the data amount of the compressed areas D1 to Dn by the information amount calculation unit 62. The data in the areas D <b> 1 to Dn compressed by the encoding unit 61 is expanded by a decoder unit 64 and stored in an image memory unit 65. .
[0058]
The deviation amount calculation unit 71 calculates the deviation between the pixel data of the areas D1 to Dn stored in the image memory unit 13 and the compressed and decompressed pixel data of the areas D1 to Dn stored in the image memory units 25b and 65. The amount is calculated.
[0059]
Here, for example, the data amount after the compression processing in the encoding unit 21 is larger than the data amount after the compression processing in the encoding unit 61, and the pixel data stored in the image memory unit 13 and the image memory unit 25b , 65, the evaluation values VC and VD calculated by the equations (4) and (5) do not satisfy the condition of the equation (6). You. For this reason, the movable terminal 17c of the signal switch 17 is set to the terminal 17b side based on the switching control signal SC, so that the compressed image data signal CC which is the data of the areas D1 to Dn that have been compressed by the encoding unit 61 is selected. The signal is supplied to the signal multiplexing unit 18.
[0060]
The signal multiplexing unit 18 generates a multiplexed signal MS from the compressed image data signal CC, the compressed audio data signal AU, and the switching control signal SC, as in the first embodiment.
[0061]
Next, the same processing is performed on the image data signals DS corresponding to the display image areas D (n + 1) to D2n, and the evaluation values VC and VD calculated by Expressions (4) and (5) are obtained. If the condition of Expression (6) is satisfied, the movable terminal 17c of the signal switch 17 is set to the terminal 17a side based on the switching control signal SC. ) To D2n are selected to generate a multiplexed signal MS.
[0062]
Thereafter, the same processing is performed on all the areas on one screen, and a compressed image data signal of an encoding method having a small data amount and a small deviation amount is selected in block units to generate a multiplexed signal MS. .
[0063]
As described above, in the above-described second embodiment, the data amount after compression and the deviation amount caused by the compression / expansion processing are calculated for each of a predetermined number of lines, and the compression amount of the encoding method with a small data amount and deviation amount is calculated. Since the image data signal is selected and transmitted, it is possible to transmit the image signal with high compression and high image quality similarly to the first embodiment.
[0064]
In the above-described second embodiment, the selection of the compressed image data signal is performed every predetermined number of lines. However, the data amount after compression and the deviation amount caused by the compression / expansion processing are calculated for each screen. Of course, a compressed image data signal of an encoding method having a small data amount and a small deviation amount may be selected for each screen.
[0065]
The encoding method is not limited to an encoding method using DCT, an ADRC encoding method, or a DPCM encoding method, and a signal may be selected from compressed data signals using three or more encoding methods. . Further, the transmitted information signal is not limited to an image signal.
[0066]
【The invention's effect】
Information signal transmission device according to the present invention And information signal transmission methods According to this, an information signal is compressed and decompressed by a plurality of encoding methods, and a compression signal of an optimal encoding method is selected based on a data amount after the compression processing or a deviation amount generated by the compression and decompression processing. Therefore, for example, when the information signal is an image signal, the image signal can be transmitted with high compression and high image quality. Also, since the transmitted compressed signal is transmitted together with information indicating the encoding method, the compressed signal can be easily expanded based on this information.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a first embodiment of an information signal transmission device according to the present invention.
FIG. 2 is a diagram illustrating a configuration of an encoding unit 31.
FIG. 3 is a diagram illustrating a configuration of a decoder unit 34;
FIG. 4 is a diagram illustrating the operation of the first embodiment.
FIG. 5 is a diagram illustrating a configuration of a multiplexed signal.
FIG. 6 is a diagram showing a configuration of an information signal transmission device according to a second embodiment of the present invention.
FIG. 7 is a diagram illustrating an operation of the second embodiment.
[Explanation of symbols]
11 A / D converter
12 Blocking part
13, 23, 25, 25b, 33, 35, 63, 65 Image memory unit
15, 71 Deviation amount calculation unit
16,72 signal selection processing unit
17 Signal switch
18 signal multiplexing unit
21, 31, 61 encoding unit
22, 22b, 32, 62 Information amount calculation unit
24, 34, 64 decoder unit
41 Maximum value detector
42 Minimum value detector
43 Delay Unit
44, 45 Subtraction unit
46 Quantization unit
47 Multiplexer
51 Demultiplexer
52 Inverse quantization unit
53 Adder

Claims (8)

Encoding means for dividing the information signal on one screen into fixed blocks, compressing the divided information signals of the block by a plurality of different encoding methods, and obtaining compressed signals of the respective encoding methods;
Data amount calculation means for calculating the data amount of each of a plurality of compressed signals corresponding to the information signal of the block obtained by the encoding means,
Decoding means for respectively expanding a plurality of compressed signals corresponding to the information signal of the block obtained by the encoding means,
Deviation amount calculating means for calculating a deviation amount between the information signal and each decompressed signal obtained by the decoding means,
Signal selection means for selecting one signal from the plurality of compressed signals corresponding to the information signal of the block;
Data transmission means for adding and transmitting information to a compressed signal corresponding to the information signal of the block selected by the signal selection means,
The signal selection means selects one signal from the plurality of compressed signals based on an evaluation value obtained by adding a result of weighting the amount of data and a result of weighting the amount of deviation in each of the plurality of encoding schemes. > An information signal transmission device characterized by the above. 2. The information signal transmission device according to claim 1, wherein the information added by the data transmission means includes information indicating a coding scheme of the compressed signal selected by the signal selection means. The encoding means,
A first encoding unit that detects a DCT coefficient by performing discrete cosine transform on the information signal in units of the fixed block, and quantizes and encodes the DCT coefficient to generate a compressed signal. The information signal transmission device according to claim 1. The encoding means,
A maximum value and a minimum value of the information signal are detected in units of the fixed block, a dynamic range is detected from the maximum value and the minimum value, and a signal obtained by subtracting the minimum value from the information signal is determined according to the dynamic range. 4. The information signal transmitting apparatus according to claim 3 , further comprising a second encoding unit that quantizes the compressed signal to generate a compressed signal. An encoding procedure of dividing an information signal on one screen into fixed blocks, compressing the divided information signals of the block by a plurality of different encoding schemes, and obtaining compressed signals of the respective encoding schemes;
A data amount calculation step of calculating the data amount of each of the plurality of compressed signals corresponding to the information signal of the block obtained in the encoding step,
A decoding procedure for decompressing a plurality of compressed signals corresponding to the information signal of the block obtained in the encoding procedure,
A deviation amount calculation procedure for calculating a deviation amount between the information signal and each decompressed signal obtained in the decoding step,
A signal selecting procedure for selecting one signal from the plurality of compressed signals corresponding to the information signal of the block;
A data transmission procedure for adding and transmitting information to a compressed signal corresponding to the information signal of the block selected in the signal selection procedure ,
In the signal selection procedure, one signal is selected from the plurality of compressed signals based on an evaluation value obtained by adding a result of weighting the amount of data and a result of weighting the amount of deviation in each of the plurality of encoding schemes. > An information signal transmission method characterized in that: 6. The information signal transmission method according to claim 5 , wherein the information added in the data transmission procedure includes information indicating a coding scheme of the compressed signal selected in the signal selection procedure . The encoding procedure is as follows:
A first encoding step of detecting a DCT coefficient by discrete cosine transform of the information signal in units of the fixed block, and quantizing and encoding the DCT coefficient to generate a compressed signal. The information signal transmission method according to claim 5 . The encoding procedure is as follows:
A maximum value and a minimum value of the information signal are detected in units of the fixed block, a dynamic range is detected from the maximum value and the minimum value, and a signal obtained by subtracting the minimum value from the information signal is determined according to the dynamic range. The information signal transmission method according to claim 7, further comprising a second encoding procedure of generating a compressed signal by performing quantization.

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