JP4640382B2 - Data file compression apparatus, program, and data file compression method - Google Patents

Description

  The present invention relates to a data file compression apparatus, a program, and a data file compression method for compressing a data file.

  There are various compression methods for compressing data files. For example, there are RLE (Run Length Encoding) method, LZ (Lempel Ziv) method, etc. as compression methods for performing compression by paying attention to the bit pattern arrangement of the data file, and paying attention to the occurrence frequency of the bit pattern of the data file. Examples of the compression method for performing compression include a Huffman method, an Arithmatic method, and a Range Coder method. In order to increase the compression efficiency of the data file, a technique is known in which the data file is compressed by all the compression methods, and all the generated compressed files are compared to leave only the compressed file having the highest compression efficiency. (For example, refer to Patent Document 1). According to this technology, as a result, the data file can be compressed by a compression method having the highest compression efficiency among all the compression methods.

Japanese Patent Laying-Open No. 2003-189111 (FIG. 1)

  Depending on the contents of the data file, there may be a case where a compressed file with higher compression efficiency can be obtained by using double compression in which a compressed file compressed by one compression method is further compressed by another compression method. . However, if it is attempted to verify all the compression procedures of the double compression in all of the plurality of compression methods, the number of compression procedures becomes enormous, and it takes too much time to compress the data file.

  Therefore, an object of the present invention is to provide a data file compression apparatus, a program, and a data file compression method capable of quickly compressing a data file with high compression efficiency.

  A data file compression apparatus according to the present invention includes a data compression unit that compresses a data file by any one of a plurality of different compression methods, and compresses the data file by each of the plurality of compression methods. Based on the first compression instruction means for instructing the data compression means and the plurality of compressed files generated by the data compression means in accordance with the instruction of the first compression instruction means, the bit pattern arrangement in the plurality of compression methods The first compression method, which is the compression method having the highest compression efficiency among the compression methods performing compression by paying attention, and the compression efficiency having the highest compression efficiency among the compression methods performing compression by paying attention to the occurrence frequency of bit patterns. Detection means for detecting a high second compression method, and a second compressed file further compressed by the first compression method. Compressing the formula, and, and a second compression instruction means for instructing said data compressing means to compress in the further first compression method compressed compressed file in the second compression system. And a selecting means for selecting a compressed file having the highest compression efficiency among a plurality of compressed files generated by the data compressing means in accordance with instructions from the first and second compression instructing means.

  The program according to the present invention includes a data compression unit that compresses a data file using any one of a plurality of different compression methods, and the data compression unit that compresses a data file using each of the plurality of compression methods. Based on the plurality of compressed files generated by the data compression unit in response to an instruction from the first compression instruction unit, the compression is performed focusing on the bit pattern arrangement in the plurality of compression methods. The first compression method that is the compression method with the highest compression efficiency among the compression methods to be performed and the compression method with the highest compression efficiency among the compression methods that perform compression by focusing on the occurrence frequency of bit patterns Detection means for detecting a certain second compression method, and further compressing the compressed file compressed by the first compression method by the second compression method And a second compression instruction means for instructing the data compression means to further compress the compressed file compressed by the second compression method by the first compression method, and the first and second compression instruction means. The computer is caused to function as a selection unit that selects a compressed file having the highest compression efficiency among a plurality of compressed files generated by the data compression unit according to each instruction.

  The data file compression method according to the present invention includes a first compression step of compressing a data file with a plurality of different compression methods, and a plurality of compression methods based on the plurality of compressed files generated in the first compression step. The first compression method that is the compression method having the highest compression efficiency among the compression methods that perform compression focusing on the arrangement of bit patterns, and the compression method that performs compression focusing on the frequency of occurrence of bit patterns A detection step of detecting the second compression method, which is the compression method having the highest compression efficiency, and further compressing the compressed file compressed by the first compression method by the second compression method; and A second compression step for instructing the data compression means to further compress the compressed file compressed by the second compression method using the first compression method.And a selecting step of selecting a compressed file having the highest compression efficiency among the plurality of compressed files generated in each of the first and second compression steps.

  The inventor of the present invention achieves compression efficiency when double compression is performed using a compression method that performs compression by focusing on the arrangement of bit patterns and a compression method that performs compression by focusing on the occurrence frequency of bit patterns. I found that it was very different. Therefore, according to the present invention, the first compression method having the highest compression efficiency among the compression methods that perform compression by focusing on the arrangement of bit patterns and the compression method that performs compression by focusing on the frequency of occurrence of bit patterns. By detecting the second compression method having the highest compression efficiency among them and verifying the compression procedure of the double compression only between them, it is possible to efficiently specify the compression procedure with the high compression efficiency. Thereby, compared with the case where the compression procedure of double compression is verified about all the compression systems, the compression file with high compression efficiency can be produced | generated rapidly.

  In the present invention, in the plurality of compression schemes, the compression scheme that performs compression focusing on the bit pattern arrangement is at least one of the RLE (Run Length Encoding) scheme and the LZ (Lempel Ziv) scheme, The compression method that performs compression by paying attention to the occurrence frequency of the pattern may be at least one of the Huffman method, the Arithmatic method, and the Range Coder method.

  In the present invention, the storage means for storing the data file supplied from the outside and the code indicating the compression procedure for generating the compressed file selected by the selection means for the data file are recorded in the header of the data file. A determination means for determining whether or not the data file has been recorded; and when the determination means determines that the code is recorded in a header of the data file, the data file is compressed by the compression procedure indicated by the code. A third compression instruction means for instructing the data compression means, and when the determination means determines that the code is not recorded in the header of the data file, the code indicating the compression procedure is stored in the storage means. Recording means for recording in the header of the data file stored in the memory, and When it is determined that the code is not recorded in the file, the compressed file selected by the selection unit is transmitted to the outside, and when it is determined that the code is recorded, the third compression instruction unit instructs It is preferable to further comprise a transmission unit for transmitting the compressed file generated by the data compression unit to the outside.

  According to this, when a series of compression processing of a data file is performed once, a code indicating a compression procedure with high compression efficiency is recorded in the header of the data file. Therefore, when the data file is compressed again, the data A compression procedure with high compression efficiency for a file can be immediately identified. Thereby, a compressed file with high compression efficiency can be generated more quickly.

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

  FIG. 1 is a functional block diagram of a control apparatus which is a data file compression apparatus according to a preferred embodiment of the present invention. As shown in FIG. 1, the control device 1 is realized by a control program that is activated on a PC (personal computer). The control device 1 controls the ink jet printer 2 and is connected to the ink jet printer 2 through a USB (Universal Serial Bus) so as to be communicable. In addition, the control device 1 compresses an image file (data file) P including image data captured from the outside and transmits it to the inkjet printer 2 (function as a data file compression device), and based on an instruction from the user The inkjet printer 2 is controlled so that an image related to the image file is printed. In the following description, the function of the control device 1 as a data file compression device will be mainly described.

  The control device 1 includes an image file storage unit (storage unit) 11, a code determination unit (determination unit) 12, a first compression instruction unit (first compression instruction unit) 13, a detection unit (detection unit) 14, Second compression instruction section (second compression instruction means) 15, third compression instruction section (third compression instruction means) 16, data compression section (data compression means) 17, and transmission file selection section (selection means) 18 A code recording unit (recording unit) 19, a USB controller (transmission unit) 20, and an image editing unit 30. The image file storage unit 11 stores an image file P supplied from the outside via a memory card (not shown) or the like. The image file P has a header in which file information is recorded and a data body in which image data is recorded. The code determination unit 12 determines whether or not a code indicating a compression procedure by the data compression unit 17 is recorded in the header of the image file P stored in the image file storage unit 11. This code will be described in detail later.

  The data compression unit 17 will be described with reference to FIG. FIG. 2 is a functional block diagram of the data compression unit 17. As shown in FIG. 2, the data compression unit 17 performs the RLE method, the LZ method, the Huffman method, the Arithmetic method, and the like according to instructions from the first compression instruction unit 13, the second compression instruction unit 15, and the third compression instruction unit 16. The data body of the image file P is compressed by one of the compression methods selected from a total of five compression methods of the Range Coder method. Note that the RLE method and the LZ method are compression methods that belong to a compression method (hereinafter referred to as compression method X) that performs compression by paying attention to the arrangement of bit patterns, and the Huffman method, Arithmetic method, and Range Coder method are bit methods. This is a compression method belonging to a compression method (hereinafter referred to as compression method Y) for performing compression by paying attention to the frequency of occurrence of patterns. In the following description, the compressed file compressed by the RLE method is compressed file A, the compressed file compressed by the LZ method is compressed file B, the compressed file compressed by the Huffman method is compressed by the compressed file C, and the Arimatic method. The compressed file is referred to as a compressed file D, and the compressed file compressed by the Range Coder method is referred to as a compressed file E.

  Returning to FIG. 1, when the code determination unit 12 determines that the code indicating the compression procedure is not recorded in the header of the image file P, the first compression instruction unit 13 converts the data body of the image file P into the above-described data body. The data compression unit 17 is instructed to perform compression by each of the five compression methods. In response to an instruction from the first compression instruction unit 13, the data compression unit 17 compresses the data body of the image file P using each of the five compression methods to generate compressed files A to E.

  The detection unit 14 compares the file capacities of the compressed files A and B generated by the data compression unit 17 in accordance with the instruction from the first compression instruction unit 13 and has the highest compression efficiency among the compression methods belonging to the compression method X. The first compression method, which is a high compression method, is detected, and the file capacities of the compressed files C to E generated by the data compression unit 17 according to the instruction of the first compression instruction unit 13 are compared with each other, and belong to the compression method Y The second compression method, which is the compression method having the highest compression efficiency among the compression methods, is detected.

  The function of the second compression instruction unit 15 will be described with reference to FIG. FIG. 3 is a block diagram illustrating a compression procedure performed by the data compression unit 17 in accordance with an instruction from the second compression instruction unit 15. In FIG. 3, the compression file B generated by the LZ method with respect to the compression method X has the highest compression efficiency, and the compression file D generated by the Arithmatic method with respect to the compression method Y has the highest compression efficiency. And Thereby, the detection unit 14 detects the LZ method as the first compression method, and detects the Arithmetic method as the second compression method. As shown in FIG. 3, the second compression instructing unit 15 further converts the compressed file (compressed file B) compressed by the first compression method (LZ method in FIG. 3) into the second compression method (Arithmetic method in FIG. 3). And instructing the data compression unit 17 to compress the compressed file (compressed file D) compressed by the second compression method using the first compression method. In response to an instruction from the second compression instruction unit 15, the data compression unit 17 generates a compressed file F by further compressing the compressed file compressed by the first compression method using the second compression method, and compressing the compressed file using the second compression method. The compressed file thus generated is further compressed by the first compression method to generate a compressed file G.

  When the code determination unit 12 determines that the code indicating the compression procedure is recorded in the header of the image file P, the third compression instruction unit 16 uses the compression means indicated by the code or a combination of the compression means to generate the image file. Instructs the data compression unit 17 to compress the data body of P. In response to an instruction from the third compression instruction unit 16, the data compression unit 17 generates a compressed file by compressing the data body of the image file P by the compression procedure indicated by the code.

  When the code determination unit 12 determines that the code indicating the compression procedure is not recorded in the header of the image file P, the transmission file selection unit 18 generates the data compression unit 17 according to the instruction of the first compression instruction unit 13 The compressed files A to E and the file capacities of the compressed files F and G generated by the data compression unit 17 according to the instruction of the second compression instruction unit 15 are compared with each other, and the compression efficiency of the compressed files A to G is the highest. Select a compressed file with a high value. The code recording unit 19 is a code indicating the compression procedure related to the compressed file selected by the transmission file selecting unit 18 when the code determining unit 12 determines that the code indicating the compression procedure is not recorded in the header of the image file P. Are recorded in the header of the image file P.

  When the code determination unit 12 determines that the code indicating the compression procedure is not recorded in the header of the image file P, the USB controller 20 transmits the compressed file selected by the transmission file selection unit 18 to the inkjet printer 2, When the code determination unit 12 determines that a code indicating the compression procedure is recorded in the header of the image file P, the data compression unit 17 uses the third compression instruction unit 16 to convert the data body of the image file P to the code The compressed file compressed by the compression means indicated by is transmitted to the inkjet printer 2.

  The image editing unit 30 edits the image data of the data body of the image file P stored in the image file storage unit 11 by a user operation. Further, the image editing unit 30 clears the area where the code in the header of the image file P is recorded when the editing result related to the data body of the image file P is stored.

  Next, the operation of the control device 1 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the control device 1. As illustrated in FIG. 4, when the user instructs the control device 1 to transmit the image file P to the inkjet printer 2 in a state where the image file P is stored in the image file storage unit 11, step S <b> 101 ( Hereinafter, the code determination unit 12 records the code indicating the compression procedure by the data compression unit 17 in the header of the image file P stored in the image file storage unit 11. It is judged whether it is done. When the code determination unit 12 determines that a code indicating the compression procedure is not recorded in the header of the image file P (S101: NO), the process proceeds to S102, and the first compression instruction unit 13 receives the data of the image file P. The data compression unit 17 is instructed to compress the main body by each of the five compression methods. In response to an instruction from the first compression instruction unit 13, the data compression unit 17 compresses the data body of the image file P using each of the above five compression methods to generate compressed files A to E.

  Thereafter, the process proceeds to S103, and the detection unit 14 compares the file capacities of the compressed files A and B with each other, and detects the first compression method that is the compression method having the highest compression efficiency among the compression methods belonging to the compression method X. At the same time, the file capacities of the compressed files C to E are compared with each other, and the second compression method that is the compression method having the highest compression efficiency among the compression methods belonging to the compression method Y is detected.

  Thereafter, the process proceeds to S104, where the second compression instruction unit 15 further compresses the compressed file compressed by the first compression method by the second compression method, and further compresses the compressed file compressed by the second compression method. Instructs the data compression unit 17 to perform compression using the first compression method. In response to an instruction from the second compression instruction unit 15, the data compression unit 17 further compresses the compressed file compressed by the first compression method using the second compression method, and generates a compressed file F. In step S105, the data compression unit 17 generates a compressed file G by further compressing the compressed file compressed by the second compression method according to the instruction of the second compression instruction unit 15. .

  Thereafter, the process proceeds to S106, and the transmission file selection unit 18 compares the file capacities of the compressed files A to G, and selects the compressed file having the highest compression efficiency among the compressed files A to G. Thereafter, the process proceeds to S107, where the code recording unit 19 records a code indicating the compression procedure related to the compressed file selected by the transmission file selecting unit 18 in the header of the image file P. In step S108, the USB controller 20 transmits the compressed file selected by the transmission file selection unit 18 to the inkjet printer 2. Then, the flowchart of FIG. 4 ends.

  On the other hand, if the code determination unit 12 determines in S101 that a code indicating the compression procedure is recorded in the header of the image file P (S101: YES), the process proceeds to S109, and the third compression instruction unit 16 determines that the code The data compression unit 17 is instructed to compress the data body of the image file P by the compression means indicated by. The data compression unit 17 generates a compressed file by compressing the data body of the image file P by the compression means indicated by the code in accordance with an instruction from the third compression instruction unit 16. Then, the process proceeds to S <b> 110, and the USB controller 20 transmits the compressed file compressed by the data compression unit 17 to the inkjet printer 2 in accordance with an instruction from the third compression instruction unit 16. Then, the flowchart of FIG. 4 ends.

  In the inkjet printer 2, when the compressed file transmitted from the control device 1 is received, the received compressed file is expanded to generate an image file P, and an image related to the image file P is generated based on an instruction from the user. Print on printing paper.

  Next, the operation of the image editing unit 30 will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the image editing unit 30. As shown in FIG. 5, when the image editing unit 30 is instructed by the user to start image editing related to the data body of the image file P with the image file P stored in the image file storage unit 11. In step S201, the image data related to the image file P is developed in the work area on the memory. Then, the process proceeds to S202, and the edit mode is activated. In the edit mode, the user can arbitrarily edit image data using a mouse or keyboard (not shown).

  Then, the process proceeds to S203, and it is determined whether or not the user has ended the editing mode. When the user has not ended the edit mode (S203: NO), the process proceeds to S202 and the edit mode is continued. When the user ends the edit mode (S203: YES), the process proceeds to S204 to determine whether the image data has been edited. When the image data is not edited (S204: NO), the process proceeds to S205, and the image data developed in the work area is discarded. Then, the flowchart of FIG. 5 ends.

  If the image data has been edited (S204: YES), the process proceeds to S206 to determine whether to save the edited image data. When the edited image data is not stored (S206: NO), the process proceeds to S205, and the image data developed in the work area is discarded. Then, the flowchart of FIG. 5 ends. When saving the edited image data (S206: YES), the process proceeds to S207, where the image data is saved as a new image file P stored in the image file storage unit 11, and the header of the image file P is stored. Clear the area where the compression procedure should be recorded. Then, the flowchart of FIG. 5 ends.

  As described above, according to the present embodiment described above, when double compression is performed using the compression method X that performs compression by focusing on the bit pattern arrangement and the compression method Y that performs compression by focusing on the occurrence frequency of bit patterns. Since the compression efficiency differs greatly, the first compression method having the highest compression efficiency among the compression methods X and the second compression method having the highest compression efficiency among the compression methods Y are detected, and between these, Only by verifying the compression procedure of double compression, a compression procedure with high compression efficiency can be identified efficiently. Thereby, compared with the case where the compression procedure of double compression is verified about all the five compression systems, a compression file with high compression efficiency can be produced | generated rapidly.

  In the present invention, if a series of compression processing of the image file P is performed once, a code indicating a compression procedure with high compression efficiency is recorded in the header of the image file P. Therefore, the image file P is compressed again. When doing so, a compression procedure with high compression efficiency can be immediately identified. Thereby, a compressed file with high compression efficiency can be generated more quickly.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, the data compression unit 17 uses the compression method selected from the five compression methods of the RLE method, the LZ method, the Huffman method, the Arithmatic method, and the Range Coder method for the image file P. Although it is the structure which compresses a data main body, the structure which a data compression part compresses the data main body of the image file P by the compression method selected from the compression method of 2-4 or 6 or more may be sufficient. The data body of the image file P may be compressed by a compression method other than these five compression methods. In addition, if at least one compression method is included for each of the compression methods X and Y, the data compression unit converts the data body of the image file P with another compression method that does not belong to any of the compression methods X and Y. A compressible configuration may be used. In this case, the data compression unit generates a compressed file by compressing the data body of the image file P by the other compression method according to the instruction of the first compression instruction unit, and the transmission file selection unit includes the compressed file. It is preferable that the compressed file with the highest compression efficiency is selected.

  In the above-described embodiment, the control device 1 includes the code recording unit 19 that records the code indicating the compression procedure related to the compressed file selected by the transmission file selecting unit 18 in the header of the image file P. However, the structure which does not have the code | symbol recording part 19 may be sufficient.

  Furthermore, in the above-described embodiment, the control device 1 is configured to transmit the compressed file to the inkjet printer 2 via the USB controller 20, but may be configured to transmit the compressed file to a device other than the inkjet printer 2. Alternatively, the compressed file may be transmitted by communication means other than USB, or the compressed file may not be transmitted.

  In addition, in the above-described embodiment, the control device 1 is configured by a program that is activated on a PC, but may be configured by a program that is activated on a computer other than the PC.

  Furthermore, in the above-described embodiment, the data body of the image file P including the image data is compressed. However, the data file may be in any format including other data such as moving image data and audio data. The data file may be a compressed file compressed in advance.

It is a functional block diagram of a control device concerning an embodiment of the present invention. It is a functional block diagram of the data compression part shown in FIG. FIG. 5 is a block diagram illustrating a compression procedure performed by a data compression unit according to an instruction from a second compression instruction unit illustrated in FIG. 1. It is a flowchart which shows operation | movement of the control apparatus shown in FIG. It is a flowchart which shows operation | movement of the image editing part shown in FIG.

Explanation of symbols

1 Control device (data file compression device)
2 Inkjet printer 11 Image file storage unit (storage means)
12 Code determination unit (determination means)
13 First compression instruction section (first compression instruction means)
14 Detection part (detection means)
15 Second compression instruction section (second compression instruction means)
16 Third compression instruction section (third compression instruction means)
17 Data compression unit (data compression means)
18 Transmission file selection part (selection means)
19 Code recording section (recording means)
20 USB controller (transmission means)
30 Image Editor P Image file (data file)

Claims (5)

Data compression means for compressing the data file by any one of the compression methods selected from a plurality of different compression methods;
First compression instruction means for instructing the data compression means to compress a data file with each of the plurality of compression methods;
Based on a plurality of compressed files generated by the data compression means in accordance with an instruction from the first compression instruction means, the compression is the most compressed among the compression methods in which compression is performed by paying attention to the bit pattern arrangement in the plurality of compression methods. The first compression method, which is the compression method with high efficiency, and the second compression method, which is the compression method with the highest compression efficiency among the compression methods that perform compression by paying attention to the occurrence frequency of the bit pattern, are detected. Detection means;
Compressing the compressed file compressed by the first compression method by the second compression method, and further compressing the compressed file compressed by the second compression method by the first compression method. Second compression instruction means for instructing the compression means;
Selecting means for selecting a compressed file having the highest compression efficiency among a plurality of compressed files generated by the data compressing means in accordance with the respective instructions of the first and second compression instructing means. Data file compressor.   In the plurality of compression methods, the compression method for performing compression by paying attention to the arrangement of bit patterns is at least one of the RLE (Run Length Encoding) method and the LZ (Lempel Ziv) method, and the frequency of occurrence of bit patterns 2. The data file compression apparatus according to claim 1, wherein the compression method that performs compression while paying attention is at least one of a Huffman method, an Arithmatic method, and a Range Coder method. Storage means for storing externally supplied data files;
Determining means for determining whether or not a code indicating a compression procedure for generating a compressed file selected by the selecting means with respect to the data file is recorded in a header of the data file;
A third compression instruction for instructing the data compression means to compress the data file by the compression procedure indicated by the code when the determination means determines that the code is recorded in a header of the data file; Means,
Recording means for recording the code indicating the compression procedure in the header of the data file stored in the storage means when the determination means determines that the code is not recorded in the header of the data file; ,
When the determination unit determines that the code is not recorded in the header of the data file, the compressed file selected by the selection unit is transmitted to the outside, and when it is determined that the code is recorded, 3. The data file compression apparatus according to claim 1, further comprising: a transmission unit that transmits the compressed file generated by the data compression unit according to an instruction from the third compression instruction unit to the outside. A data compression means for compressing the data file by any one compression method selected from a plurality of different compression methods;
First compression instruction means for instructing the data compression means to compress a data file with each of the plurality of compression methods;
Based on a plurality of compressed files generated by the data compression means in accordance with an instruction from the first compression instruction means, the compression is the most compressed among the compression methods in which compression is performed by paying attention to the bit pattern arrangement in the plurality of compression methods. The first compression method, which is the compression method with high efficiency, and the second compression method, which is the compression method with the highest compression efficiency among the compression methods that perform compression by paying attention to the occurrence frequency of the bit pattern, are detected. Detection means,
Compressing the compressed file compressed by the first compression method by the second compression method, and further compressing the compressed file compressed by the second compression method by the first compression method. Second compression instruction means for instructing the compression means; and
A computer is caused to function as a selection unit that selects a compressed file having the highest compression efficiency among a plurality of compressed files generated by the data compression unit according to instructions of the first and second compression instruction units. program. A first compression step of compressing the data file with each of a plurality of different compression methods;
The compression method having the highest compression efficiency among the compression methods in which compression is performed by paying attention to the arrangement of bit patterns in the plurality of compression methods based on the plurality of compressed files generated in the first compression step. A detection step of detecting a first compression method and a second compression method that is the compression method having the highest compression efficiency among the compression methods that perform compression by paying attention to the occurrence frequency of a bit pattern;
Compressing the compressed file compressed by the first compression method by the second compression method, and further compressing the compressed file compressed by the second compression method by the first compression method. A second compression step instructing the compression means;
A data file compression method comprising: a selection step of selecting a compressed file having the highest compression efficiency among a plurality of compressed files generated in each of the first and second compression steps.

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