JP2004015743A - Compressing/encoding/transmitting apparatus and method, and decompressing/decoding/receiving apparatus and method for road traffic information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a compressing/encoding/transmitting apparatus and method for road traffic information, and a decompressing/decoding/receiving apparatus and method therefor with which the compression effect of the road traffic information can be expected and a large quantity of pieces of road traffic information can be transmitted. <P>SOLUTION: The compressing/encoding/transmitting apparatus has an encoding means 21 for creating encoded information by encoding the road traffic information and a compressing means 41 for creating a compressed code by compressing the encoded information. The encoding means 21 is provided with a description language character string creating means 22 for receiving the road traffic information and creating a description language such as character strings of XML, an information class word sorting means 23 for sorting words by information classes, and a dictionary creating means 25 for creating each dictionary by registering the words by the information classes. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to compression encoding, and more particularly, to a compression encoding transmission apparatus for road traffic information, a decompression decoding reception apparatus thereof, a compression encoding transmission method thereof, and a decompression decoding reception method.
[0002]
[Prior art]
There is a demand for transmission of a larger amount of information to a user of a mobile unit related to this kind of road traffic information, but a limited transmission path such as a VICS link related to road traffic information provided by the applicant for the mobile unit. Then, it takes time to send a large amount of information due to the limitation of the amount of information. On the other hand, if a wide transmission path is used, a large amount of information can be obtained, but the cost is high.
[0003]
For this reason, Japanese Patent Application Laid-Open No. 8-340257 (FM multiplex information processing apparatus and its related art) discloses a conventional example of compression of road traffic information in order to convert the information amount into a compressed small amount and transmit the information in a short time. Method).
[0004]
[Problems to be solved by the invention]
However, in these conventional examples, the compression ratio cannot be reduced to 10% or less when the road traffic information is compressed and encoded. Therefore, a compression effect of road traffic information cannot be expected, and a large amount of road traffic information cannot be transmitted.
[0005]
Therefore, a technical problem of the present invention is to provide a road traffic information compression-encoding / transmission apparatus, a decompression / decoding reception apparatus thereof, and a compression-encoding / transmission method thereof, which can expect a compression effect of road traffic information and can transmit a large amount of road traffic information , And its decompression decoding reception method.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a road traffic information compression-encoding transmission device for transmitting road traffic information as a compression code, wherein the compression-encoding transmission device encodes the road traffic information. Encoding means for generating encoded information, and compressing means for compressing the encoded information to generate the compressed code, wherein the encoding means receives the road traffic information, A description language character string creating means for creating a character string code using the description language of the present invention, and an information type word classification for receiving the character string code, dividing the word into a plurality of words, and classifying the words into a predetermined information type Means for creating a dictionary in which words classified into the predetermined information type are registered, and a dictionary creating means for creating a dictionary. .
[0007]
The invention according to claim 6 is a compression encoded transmission method of road traffic information for transmitting road traffic information in a compressed code, wherein the compression encoded transmission method encodes the road traffic information. An encoding step for generating encoded information; and a compression step for compressing the encoded information to generate the compression code. The encoding step includes receiving the road traffic information, A description language character string creating step for creating a character string code using the description language of the above, an information type word classification for receiving the character string code, dividing the word into a plurality of words, and classifying the words into a predetermined information type And a dictionary creating step for creating respective dictionaries in which words classified into the predetermined information type are registered. .
[0008]
According to the first or sixth aspect of the invention, the road traffic information is converted into a character string code in a predetermined description language by the description language character string creation unit. The character string code is divided into a plurality of words by the information type word classification means, and is classified into a predetermined information type. Each dictionary is created by registering words classified into a predetermined information type.
[0009]
According to a second aspect of the present invention, the dictionary creation unit receives a word classified into the predetermined information type, a specific word setting unit for setting a specific word, and receives the specific word. A use frequency word descending order extraction means for sorting and extracting the use frequency in descending order so that the use frequency is calculated; and receiving the use frequency, calculating a compression rate of the specific word and classifying the compression rate into a predetermined compression rate range. 2. The apparatus according to claim 1, further comprising: a word compression rate classifying unit for performing the compression and encoding.
[0010]
According to the second aspect of the present invention, the specific word is set by the specific word setting means from the words classified into the predetermined information type. The specific words are calculated in frequency of use and are sorted and extracted in descending order. As a result of calculating the compression ratio from the use frequency, a predetermined compression ratio range is classified.
[0011]
According to a third aspect of the present invention, the compression unit receives the encoded information, and describes a description for collating whether a description language character string of the encoded information matches a word registered in the dictionary. A language character string collating means, a word number string setting means for setting the encoding information to a word number string when the collation is coincident, and receiving and setting the respective dictionary to a desired dictionary 2. The road traffic information according to claim 1, further comprising: a dictionary switch setting unit for performing the conversion, and an embedded character string setting unit for embedding the encoded information as it is when the collation does not match. Of the present invention.
[0012]
According to the third aspect of the present invention, the description language character string collating means collates whether the description language character string of the encoded information matches a word registered in the dictionary. If the comparisons match, the word number sequence setting means sets the encoded information to the word number sequence, and the word number sequence is converted into a compressed code. Further, the dictionary is switched to a desired dictionary by the dictionary switching setting means. If the collation does not match, the embedded character string setting unit embeds the description language character string of the encoded information as it is and converts it into a compressed code.
[0013]
The invention according to claim 4 is a decompression decoding reception device for road traffic information, wherein the decompression decoding reception device decompresses the compressed code and generates decompression information; Decoding means for decoding the encoded information into the road traffic information, wherein the decompression means receives the compression code, and decompresses and prepares a dictionary; and And a decompression dictionary changing unit for receiving and changing the extracted dictionary, and further comprising a dictionary storage unit for storing the decompressed dictionary. is there.
[0014]
The invention according to claim 7 is a decompression decoding reception method for road traffic information, wherein the decompression decoding reception method decompresses the compression code and generates decompression information; A decoding step for decoding the encoded information into the road traffic information, wherein the decompressing step receives the compression code, and decompresses and creates a dictionary. Decompressing dictionary receiving step for receiving and changing the extracted dictionary, and further comprising a dictionary storing step for storing the decompressed dictionary. is there.
[0015]
According to the invention described in claim 4 or claim 7, the compression code is decompressed by the decompression means to generate encoded information. The decompressed dictionary is created by the decompression dictionary creation means of the decompression means. The decompressed dictionary is stored by the dictionary storage unit. On the other hand, the decompressed dictionary is changed.
[0016]
According to a fifth aspect of the present invention, the decoding means includes: a dictionary restoring means for restoring the decompressed dictionary; and a description language character string restoring means for restoring a description language character string in the restored dictionary. 5. A decompression decoding reception of road traffic information according to claim 4, further comprising means for restoring an embedded character string embedded in place of the description language character string. Device.
[0017]
According to the fifth aspect of the present invention, the decompressed dictionary is restored by the dictionary restoring unit. The description language character string restored by the description language character string restoration means is restored. The embedded character string is restored by the embedded character string restoring means.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A description will be given, with reference to the drawings, of a road traffic information compression encoding transmission apparatus, a decompression decoding reception apparatus, a compression encoding transmission method, and a decompression decoding reception method according to an embodiment of the present invention.
(Compression coded transmission device for road traffic information)
[0019]
FIG. 1 is a block diagram of a device for compressing and encoding road traffic information according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a dictionary according to the dictionary creation unit 25 of FIG. FIG. 4 is a configuration diagram of a compression code in the word number string setting unit 45 of the compression unit 41 of FIG. FIG. 5 is a configuration diagram of the compression code dictionary of FIG. FIG. 6 is a configuration diagram of a dictionary next to the dictionary of FIG. FIG. 11 is a diagram showing the structure of the road traffic information dictionary according to the embodiment of the present invention.
[0020]
The apparatus for compressing and encoding road traffic information according to the embodiment of the present invention shown in FIG. 1 is for transmitting road traffic information as a compressed code.
[0021]
The compression encoding transmission device has an encoding unit 21 for encoding road traffic information to generate encoded information, and a compression unit 41 for compressing the encoded information to generate a compression code. The encoding unit 21 receives the road traffic information, receives a description language string creating unit 22 for creating a character string code (XML code) using a predetermined description language, for example, XML, and receives the character string code. An information type word classification means 23 for dividing into a plurality of words and classifying them into a predetermined information type, and a dictionary creation for generating respective dictionaries in which words classified into the predetermined information type are registered Means 25.
[0022]
By the way, XML can extract tags and attributes from a DTD (Document Type Definition) that defines tag information.
[0023]
The dictionary creation unit 25 receives the words classified into the predetermined information type, receives the specific words, and receives the specific words, calculates the use frequency, and arranges them in descending order. And a word compression rate classifying means 31 for receiving the usage frequency, calculating the compression rate of a specific word, and classifying the word into a predetermined compression rate range. .
[0024]
In other words, the dictionary creating unit 25 creates a dictionary by preferentially registering a word with a high frequency of use from many words in which XML codes are separated by tags.
[0025]
More specifically, first, as for the number as the data portion, except for 0, 1 to 9 are set with one word per character, and thereafter, those whose compression ratio can be calculated are selected. To create a word, extract the 8-bit or 16-bit code used in the information, combine them, create 2 characters, 3 characters, etc., and select them in order of compression rate I do. Assuming the frequency of use f, the word length L (the word length in 16-bit units is twice as long as the word in 8-bit units), and the number of bits b, the formula for the compression ratio r is as follows: It is.
[0026]
r = [1 + L + f · b / 8] / (f · L)
[0027]
FIG. 14 is a diagram showing evaluation data of the road traffic information compression encoding transmission apparatus and its decompression encoding apparatus according to the embodiment of the present invention. FIG. 15 shows the contents of the dictionary according to FIG. FIG. 16 shows an example of a compression code by the compression means 41 of FIG. FIG. 17 is another example of FIG.
[0028]
More specifically, the evaluation data shown in FIG. 14 is an actual example in which a character string in which traffic congestion information of a secondary mesh in Tokyo is described in XML is compressed. The dictionary is transmitted together with data (congestion information) during the free time at night.
[0029]
The content of the dictionary in FIG. 15 is that the number of words = 33 and the total dictionary degree = 425 (including the number of characters). "Unknown" and "start" which are 0% of the word numbers No. 12 and No. 14 in FIG. 15 mean that this data did not exist.
[0030]
In the result of FIG. 15, 6 bits are required to represent the number of 33 words. Since the word numbers 26 and 27 are used only once, they can be removed from the dictionary by using the embedded character string setting means 49. At this time, the word number 31 is specified as an embedding, and since both <conquest-info> and </ conquest-info> are used only once, the word can be removed from the dictionary by using the embedded character string setting means 49. At this time, </ conquest-info> may be used by setting, for example, the word number 30 using the dictionary switching setting unit 47 in which the dictionary number is set.
[0031]
Referring to the evaluation of FIG. 15, the word compression ratio classification unit 31 of the dictionary creation unit 31 classifies the word numbers 15 to 22 into a predetermined (less than 10%) compression ratio range in which a compression effect is provided. Further, since the word numbers 15 to 18 have a particularly large contribution, the range of the predetermined compression ratio can be changed and set each time.
[0032]
In road traffic information, specifically, in traffic jam information
1-9 numeric word setting
congestion
unknown
Beginning
End
<Conquest-info>
</ Conquest-info>
[0033]
These words are separated by a character string in the processing by the simple algorithm, or are combined in the case of a number. Some of these words may not be used in the information depending on the content of the information. For example, "unknown" and "end". However, words that are not used in the information are also included in order to make them common to all information. Therefore, at the end of the dictionary according to the present invention, a dictionary having a poor compression rate remains.
[0034]
The above-described <conquest-info> and </ conquest-info> appear only once at the beginning and at the end, but are set first to prevent division and integration. When a word of one character is used only once, the compression ratio becomes 100% or more, which is an extremely bad result. However, when the dictionary has room, the effect is small. However, if there is no room, it is necessary to create a character string so that such a one-character word does not occur.
[0035]
FIG. 13 is a configuration diagram of a dictionary having an extended function according to the dictionary creating means 25 of FIG. 1. In the dictionary words, an extended function is included in order to increase versatility.
[0036]
Among the characters to be compressed, there are character strings that are very rarely used. In the case of the direct character string of the word number 63 in FIG. 13, a direct data writing function, that is, the dictionary is not created, and the data is directly embedded in the compression code (embedded character string setting means 49 in FIG. 1). As a result, it is not necessary to increase the number of words in the dictionary unnecessarily.
[0037]
For example, if there are 65 words, words must be represented by 7 bits. If the three types are used only once, if they are not registered in the dictionary and are directly put into the compression code, the words will be 63 types and become a 6-bit compression code. Overall, it is 6/7, and the compression effect is large.
[0038]
The compression unit 41 receives the description language character string of the encoded information, and compares the description language character string with the word registered in the dictionary. A word number string setting means 45 for setting a word number string and converting the encoded information into a compression code; a dictionary switching means 47 for receiving each dictionary and switching to a desired dictionary; In this case, there is provided an embedded character string setting unit 49 for embedding the encoded information as it is.
[0039]
FIG. 12 is a diagram showing dictionary switching tags.
A desired dictionary is switched from the plurality of dictionaries in FIG. 11 by the dictionary switching setting means 47 of the compression means in FIG. The special dictionary is determined in advance and stored in the dictionary storage unit 26. For example, in the dictionary 2 </ congestion-info> of FIG. 12, since the congestion information is ended, the word is used to control the congestion information to be returned from the dictionary to the common unit.
[0040]
This dictionary switching may be performed by a special number in a word. There is no character string because the word has the meaning of being specified in the dictionary.
[0041]
The above two functions are set to the highest word number. For example, when the word number is represented by 6 bits, the table is as shown in FIG. In this case, the word numbers are 62 and 63.
[0042]
(Decompression decoding receiver for road traffic information)
[0043]
FIG. 2 is a block diagram of an apparatus for decoding and decoding road traffic information according to an embodiment of the present invention.
[0044]
Next, an apparatus for decompressing and decoding road traffic information according to an embodiment of the present invention will be described with reference to FIG.
[0045]
The decompression decoding receiving device has a decompression means 75 for decompressing the compressed code to generate the coded information, and a decoding means 81 for decoding the coded information into the road traffic information. The decompression means 75 includes a decompression dictionary creation means 77 for receiving a compression code and decompressing and creating a dictionary, and a decompression dictionary change means 80 for receiving and changing the decompressed dictionary.
[0046]
On the other hand, the apparatus for decompressing and decoding road traffic information further includes a dictionary storage unit 79 for storing the decompressed dictionary.
[0047]
The decoding means 81 includes a dictionary restoring means 83 for restoring the decompressed dictionary, a description language character string restoring means 85 for restoring the restored description language character string, and an embedded descriptive word instead of the registered word. Embedded character string restoring means 87 for restoring the embedded character string.
[0048]
(Method of compressing and encoding road traffic information)
With reference to FIG. 1, a description will be given of a method for compressing and encoding road traffic information according to an embodiment of the present invention. In addition, each means shall be read as a process.
[0049]
FIG. 7 is a flowchart of a dictionary creation process according to the dictionary creation means 25 of FIG. FIG. 8 is a flowchart of a compression code creation process according to the compression means 41 of FIG.
[0050]
The compression encoding transmission method includes an encoding step 21 for encoding road traffic information to generate encoded information, and a compression step 41 for compressing the encoded information to generate a compression code. An encoding step 21 receives a road traffic information, and a description language character string creating step 22 for creating a character string code using a predetermined description language. It comprises an information type word classification step 23 for classifying information into a predetermined information type, and a dictionary creation step 25 for generating respective dictionaries in which words classified into the predetermined information type are registered. .
[0051]
The dictionary creation step 25 of FIG. 1 receives a word classified into a predetermined information type, receives a specific word, and receives a specific word, and calculates a use frequency. A usage frequency word descending order extraction step 29 for sorting and extracting in descending order; a word compression rate classification step 31 for receiving the usage frequency, calculating the compression rate of a specific word, and classifying the word into a predetermined compression rate range; , Is provided.
[0052]
The dictionary creation step 25 will be described with reference to FIG. The specific word setting step 27 in FIG. 1 is step S1 in FIG. Thereby, an initial, that is, a specific word is set from the words classified into the predetermined information type.
[0053]
Steps S2 to S5 in FIG. 7 and Steps S10 to S13 are the use frequency word descending order extraction process 29 in FIG. 1, in which specific words are arranged in descending order so that the number of appearances, that is, the use frequency is calculated. Extracted. In step S2, the characters to be extracted include an 8-unit system (8-bit system) and a 16-unit system (16-bit system), and these characters are determined by the character strings of all combinations of the number of character strings set in step S3. A word is set, and the frequency of use in the XML sentence is checked in step S5, and a character string having a frequency of one or more is treated as a word.
[0054]
In steps S6 to S9, in the word compression ratio classification step 31 of FIG. 1, the compression ratio is calculated from the use frequency, and as a result, a predetermined compression ratio range is classified.
[0055]
The compression step 41 receives the encoded information, and the collation matches the description language string collation step 43 for collating whether the descriptive language character string of the encoded information matches a word registered in the dictionary. In the case, a word number string setting step 45 for setting the encoding information in a word number string, a dictionary switching setting step 47 for receiving each dictionary and switching to a desired dictionary, Comprises an embedded character string setting step 49 for embedding the encoded information as it is.
[0056]
In the description language character string collation step 43 (S3 in FIG. 8), it is collated whether or not the description language character string of the encoded information matches a word registered in the dictionary. If the collation matches, the word number sequence is converted into a compressed code as a result of setting the encoded information in the word number sequence in the word number sequence setting step 45 (S4, S5 in FIG. 8). In the dictionary switching setting step 47 (S7 in FIG. 8), the dictionary is switched to a desired dictionary. If the collation does not match, in the embedded character string setting step 49, the description language character string of the encoded information is embedded as it is and converted into a compressed code.
(Decompression decoding reception method of road traffic information)
[0057]
FIG. 9 is a flowchart of the decoding step 81 according to the decoding means 81 of FIG. FIG. 10 is a flowchart of the thawing step 75 of the thawing means 75 of FIG.
[0058]
The decompression decoding reception method for road traffic information includes a decompression step 75 for decompressing a compressed code and generating encoded information, and a decoding step 81 for decoding the encoded information into road traffic information. Have. The decompression step 75 includes a decompression dictionary creation step 77 for receiving a compression code and decompressing and creating a dictionary, and a decompression dictionary change step 80 for receiving and changing the decompressed dictionary. It further includes a dictionary storage step 79 for storing the obtained dictionary.
[0059]
The decoding step 81 in FIG. 2 includes a dictionary restoring step 83 (S1 in FIG. 9) for restoring the decompressed dictionary and setting it as this initial dictionary, and a decoding step for restoring a description language character string in the restored dictionary. A description language character string restoration step 85 (S2 to S9 in FIG. 9) and an embedded character string restoration step 87 (omitted in FIG. 9) for restoring an embedded character string embedded instead of the description language character string Prepare.
[0060]
In the decompression process shown in FIG. 10, the compression code is decompressed to generate encoded information. The decompressed dictionary is created by the decompression dictionary creation step (decompression dictionary creation means 77 in FIG. 2 and dictionary number setting step S2 in FIG. 10) in the decompression step. In the dictionary storage step 79 (dictionary storage step S8 in FIG. 10), the decompressed dictionary is stored. On the other hand, the decompressed dictionary is changed (decompression dictionary changing means 80 in FIG. 2 and dictionary number setting step S7 in FIG. 10).
[0061]
As described above, according to the present invention, a high compression ratio can be achieved for information written in characters, such as XML (Extensible Markups Language). In the case of Japan, some characters such as kanji and hiragana are handled in 2 bytes. However, 1-byte and 2-byte characters are extracted from the document to be compressed, and the most frequently used Strings are treated as words. For this reason, words may be cut off in the middle as words, but by setting such words in the dictionary, a high compression rate can be achieved. In the present invention, in order to utilize the dictionary as much as possible, words having a low compression effect are also registered in the dictionary, and a configuration with a small number of embedded characters is adopted.
[0062]
Also, since information is sent in real time every one or five minutes, a dictionary that can be used in common as much as possible is sent out at night instead of sending out a dictionary for each piece of information. This is because, in the case of road traffic information, the transmitted real-time data varies in data amount depending on traffic conditions.
[0063]
The compression effect is particularly required in a traffic congestion situation with the most data, at 8:00 in the morning, 10:00 in Tokyo, and around 18:00 at night. Therefore, in the present invention, the dictionary is set so that the compression effect is maximized when the traffic is heavy.
[0064]
The means of compression / encoding, decompression / decoding, etc. used in the present invention can be applied not only to road traffic information, but also to digital broadcast real-time information and information for mobile objects, as well as to the Internet. It can be used regardless of media.
[0065]
As described above, in the embodiment of the present invention, the description has been given of the road traffic information compression encoding transmission apparatus, its decompression decoding reception apparatus, its compression encoding transmission method, and the decompression decoding reception method. It is not done. For example, it goes without saying that the present invention can also be applied to a program for a compression encoding transmission method and a decompression decoding reception method for road traffic information.
[0066]
In the embodiment, the dictionary is transmitted together with the traffic jam data at night, but the dictionary may be downloaded and obtained through the Internet, a mobile phone, or the like.
[0067]
【The invention's effect】
The description language character string creating means according to claim 1 or 6 converts the road traffic information into a character string code in a predetermined description language. Since the character string code is divided into a plurality of words by the information type word classification means, the words are classified into predetermined information types, and respective dictionaries are created. As a result, words classified into the predetermined information types are registered. Is done. Therefore, it is possible to obtain a road traffic information compression encoding transmission apparatus or a compression encoding transmission method capable of transmitting a large amount of road traffic information by expecting a compression effect of the road traffic information.
[0068]
According to the invention described in claim 2, the specific word is set by the specific word setting means from the words classified into the predetermined information type, and as a result, the use frequency is calculated, and the specific words are arranged in descending order. Extracted. For this reason, a range of a predetermined compression ratio is classified, and a compression-encoding transmission apparatus for road traffic information that can classify a range having a desired good compression effect is obtained.
[0069]
According to the invention described in claim 3, whether or not the description language character string of the encoded information matches the word registered in the dictionary is checked by the registered word matching means. As a result of setting the encoding information in the word number sequence, the word number sequence is converted into a compression code. Also, the desired dictionary can be switched. If the comparisons do not match, the embedded character string setting means obtains a road traffic information compression-encoding transmission device that embeds the description language character string of the encoding information as it is and converts it into a compression code.
[0070]
According to the invention described in claim 4 or 7, there is provided a decompression decoding receiving apparatus or a receiving method of road traffic information capable of decompressing a compression code and generating a dictionary of coding information.
[0071]
According to the fifth aspect of the present invention, the decompressed dictionary is restored by the dictionary restoring means, the description language character string restored by the description language character string restoring means is restored, and the embedding character string restoring means restores the descriptive language string. A decompression decoding receiver for road traffic information capable of restoring a character string is obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram of a device for compressing and encoding road traffic information according to an embodiment of the present invention.
FIG. 2 is a block diagram of a decompression decoding receiver for road traffic information according to the embodiment of the present invention.
FIG. 3 is a configuration diagram of a dictionary according to the dictionary creation unit 25 of FIG. 1;
FIG. 4 is a configuration diagram of a compression code in a word number setting unit 45 of the compression unit 41 in FIG. 1;
FIG. 5 is a configuration diagram of a compression code dictionary of FIG. 4;
FIG. 6 is a configuration diagram of a dictionary next to the dictionary of FIG. 5;
FIG. 7 is a flowchart of a dictionary creation process according to the dictionary creation means 25 of FIG. 1;
FIG. 8 is a flowchart of a compression code creation process according to the compression means 41 of FIG. 1;
FIG. 9 is a flowchart of a decoding process performed by the decoding means 81 of FIG. 2;
FIG. 10 is a flowchart of a dictionary decompression and creation process according to the dictionary decompression and creation means 77 of the decompression means 75 of FIG. 2;
FIG. 11 is a diagram showing a structure of a dictionary of road traffic information according to the embodiment of the present invention.
FIG. 12 is a diagram showing dictionary switching tags.
FIG. 13 is a configuration diagram of a dictionary having an extended function according to the dictionary creation unit 25 of FIG. 1;
FIG. 14 is a diagram showing evaluation data of a road traffic information compression encoding transmission apparatus and its decompression encoding apparatus according to the embodiment of the present invention.
FIG. 15 is a diagram showing the contents of the dictionary according to FIG. 14;
FIG. 16 is an example of a compression code by the compression means 41 of FIG. 1;
FIG. 17 is another example of FIG.
[Explanation of symbols]
11 Sensor
13 Road traffic information generation means
15 VICS Center
17 Road traffic information input means
21 Encoding means
22 Description language character string creation means
23 Information classification word classification means
25 Dictionary creation means
27 Specific word setting means
29 Frequency-of-use word descending order extraction means
31 Word compression rate classification means
41 Compression means
43 Description Language String Matching Means
45 Word number string setting means
47 Dictionary switching setting means
49 Embedded character string setting means
51 Compression code modulation transmission means
71 Compressed code reception demodulation means
75 Decompression means
77 Decompression dictionary creation means
79 Dictionary storage means
80 Decompression dictionary change means
81 Decoding means
83 Dictionary restoration means
85 Dictionary registration character string restoration means
87 Embedded character string restoration means

Claims (7)

A road traffic information compression encoding transmission device for transmitting road traffic information with a compression code,
The compression encoding transmission device, encoding means for encoding the road traffic information to generate encoded information,
Compression means for compressing the encoded information to generate the compression code;
Have
The encoding means,
A description language character string creating unit for receiving the road traffic information and creating a character string code using a predetermined description language;
An information type word classifying unit for receiving the character string code, dividing the word into a plurality of words, and classifying the information into predetermined information types
Dictionary creation means for creating each dictionary in which words classified into the predetermined information type are registered,
A compression-encoding transmission apparatus for road traffic information, comprising: The dictionary creation means,
A specific word setting means for receiving a word classified into the predetermined information type and setting a specific word;
Receiving the specific word, used frequency word descending order extracting means for extracting and extracting in descending order so that the usage frequency is calculated,
Receiving the use frequency, a word compression ratio classifying means for calculating a compression ratio of the specific word and classifying it into a predetermined compression ratio range;
The apparatus for compressing and encoding road traffic information according to claim 1, further comprising: The compression means,
Description language character string matching means for receiving the encoded information and collating whether a description language character string of the encoded information matches a word registered in the dictionary,
If the collation matches, a word number string setting means for setting the encoding information to a word number string;
Dictionary switch setting means for receiving each of the dictionaries and switching to and setting a desired dictionary;
If the collation does not match, embedded character string setting means for embedding the encoded information as it is,
The apparatus for compressing and encoding road traffic information according to claim 1, further comprising: A decompression decoding receiver for road traffic information,
The decompression decoding receiver,
Decompressing means for decompressing the compression code and generating encoded information;
Decoding means for decoding the encoded information into the road traffic information,
Have
The decompression means,
Decompression dictionary creation means for receiving the compression code and decompressing and creating a dictionary;
A decompression dictionary changing means for receiving and changing the decompressed dictionary;
While
A decompression decoding reception apparatus for road traffic information, further comprising a dictionary storage unit for storing the decompressed dictionary. The decoding means,
Dictionary restoration means for restoring the decompressed dictionary;
Description language string restoring means for restoring the description language string in the restored dictionary;
Embedded character string restoring means for restoring an embedded character string embedded in place of the description language character string;
5. The apparatus for decompressing and decoding road traffic information according to claim 4, further comprising: A road traffic information compression-encoding transmission method for transmitting road traffic information as a compression code,
The compression-encoding transmission method, an encoding step for encoding the road traffic information to generate encoded information,
A compression step of compressing the encoded information to generate the compression code;
Have
The encoding step includes:
A description language character string creating step for receiving the road traffic information and creating a character string code using a predetermined description language;
An information type word classification step for receiving the character string code, dividing the word into a plurality of words, and classifying the information into a predetermined information type;
A dictionary creation step for creating respective dictionaries in which words classified into the predetermined information type are registered;
And a method for compressing and encoding road traffic information. Decompression decoding reception method of road traffic information,
The decompression decoding reception method includes:
A decompression step for decompressing the compression code and generating encoded information;
A decoding step for decoding the encoded information into the road traffic information;
Have
The thawing step,
A decompression dictionary creation step for receiving the compression code and decompressing and creating a dictionary;
A decompression dictionary change step for receiving and changing the decompressed dictionary;
While
A method for decompressing and decoding road traffic information, further comprising a dictionary storage step for storing the decompressed dictionary.

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