JP2006109231A - File format conversion device, file format conversion method, and program used for file format conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a file format conversion device, a file format conversion method, and a program used for the file format conversion device, which shorten a time necessary for converting a JFIF image, and creating an EXIF image, and at the same time, create the EXIF image to be certainly reproduced. <P>SOLUTION: The file format conversion device is provided with: a JPEG marker segment extraction part 102 which extracts a plurality of marker segments from inputted JFIF image file; a compression image data extraction part 103 which extracts compressed image data; a JPEG marker segment discrimination part 104 which discriminates whether the inputted JFIF image file is compressed again, according to a parameter stored in a plurality of the respective extracted marker segments; and an EXIF creation part 109 which again uses a plurality of the extracted marker segments, and the compressed image data when it is determined that recompression is not carried out, and creates an EXIF image file. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a file format conversion apparatus, a file format conversion method, and a file format conversion for converting an image whose file format is configured by JFIF (JPEG File Interchange Format) into an image configured by EXIF (Exchangeable image file format) The present invention relates to a program used for the apparatus.

  As an image file format, JPEG (JPEG File Interchange Format), which is often used as a JPEG (Joint Photographic Experts Group) image in a personal computer, or JPEG image as a JPEG image, is often used in a digital camera. EXIF (Exchangeable image file format) for the purpose of mutual compatibility with equipment. When an EXIF image is generated by converting a file format from a JFIF image, it is general that the JFIF image is once decompressed from a compressed state and recompressed into an EXIF image. A technique for generating an EXIF image from a JFIF image is particularly required in an electronic device that inputs a JFIF image from an electronic mail, the Web, or the like, such as a personal computer or a portable terminal.

  According to the above-described file format conversion method, the circuit design of the conversion circuit for performing the file format conversion is easy. However, on the other hand, it takes time to re-compress to an EXIF image, and in a device with high processing capability such as a personal computer. On the other hand, in a device having a low processing capability such as a cellular phone, the time required for recompression is particularly a problem when converting a high-resolution image into an EXIF image. In addition, the image quality of the EXIF image generated by the conversion is deteriorated as compared with the JFIF image.

  An image file format conversion apparatus for solving such a problem is described in Patent Document 1. FIG. 7 shows a configuration diagram of a converted image file in the image file format conversion apparatus of Patent Document 1. The JFIF image file 700 includes an APP0 marker 710 and compressed image data 720. On the other hand, the EXIF image file 750 includes an APP1 marker 760 including a header, tag information, and the like, and compressed image data 720. The tag information of the APP1 marker 760 has a relationship with compressed image data such as the shooting date and time, the size of the image, and the EXIF version.

  The image file format conversion apparatus of Patent Document 1 extracts and diverts data 711, 712, and 713 applicable to the tag information of the APP1 marker 760 of the EXIF image file 750 from the APP0 marker 710 of the JFIF image file 700. The tag information of the APP1 marker 760 is generated. Subsequently, the generated tag information and the header are combined to generate an APP1 marker 760. Further, the compressed image data 720 of the JFIF image file 700 is captured, and the captured compressed image data 720 and the APP1 marker are combined to generate an EXIF image file 750.

  As described above, according to the image file format conversion device of Patent Document 1, when generating an EXIF image by converting a file format from a JFIF image, the compressed image data of the JFIF image is directly taken in as compressed image data of the EXIF image. Since this is used, there is no image degradation associated with format conversion from a JFIF image to an EXIF image.

JP 2002-218402 A

  However, the image file format conversion apparatus disclosed in Patent Document 1 does not consider parameters stored in a plurality of marker segments other than APP0 included in the JFIF image, so depending on the JFIF image, a compressed image of the JFIF image may be used. If the data is directly used as compressed image data of an EXIF image, the EXIF image cannot be correctly generated, and the generated EXIF image may not be reproduced correctly.

  The present invention has been made in view of the above circumstances, and is a file format conversion capable of generating an EXIF image that is reliably reproduced while reducing the time required to generate an EXIF image by converting a JFIF image. An object is to provide a device, a file format conversion method, and a program used for the file format conversion device.

  The file format conversion apparatus of the present invention is a file format conversion apparatus that converts a JFIF image file including a plurality of marker segments and compressed image data into an EXIF image file, and inputs the JFIF image file. Based on input means, extraction means for extracting the plurality of marker segments and the compressed image data from the input JFIF image file, and parameters stored in each of the extracted marker segments, the input Determining means for determining whether or not to re-compress the JFIF image file, and if it is determined to re-compress, re-compress the image data expanded from the compressed state to generate an EXIF image file and do not re-compress The plurality of extracted marker segments and the extracted marker segments. By diverting the compressed image data, and comprises a generating means for generating an image file of the EXIF, and output means for outputting the image file of the EXIF that the generated, a.

The file format conversion method of the present invention is a file format conversion method for converting a JFIF image file including a plurality of marker segments and compressed image data into an EXIF image file, and inputs the JFIF image file. An input step;
The input JFIF image is extracted based on an extraction step of extracting the plurality of marker segments and the compressed image data from the input JFIF image file, and parameters stored in each of the extracted marker segments. When determining whether to re-compress the file, and when determining to re-compress, when re-compressing the image data expanded from the compressed state to generate an EXIF image file and determining not to re-compress A generating step for generating an EXIF image file by diverting the extracted marker segments and the extracted compressed image data; and an output step for outputting the generated EXIF image file. It is.

  The program used in the file format conversion apparatus of the present invention causes a computer to execute each step of the file format conversion method of the present invention.

  According to this configuration, it is possible to generate an EXIF image that is reliably reproduced while reducing the time required to convert the JFIF image to generate an EXIF image.

  The file format conversion apparatus according to the present invention, when there are a plurality of DQT or DHT marker segments in the plurality of marker segments, combines the plurality of DQT or DHT marker segments into one each. Including those equipped with synthesis means.

  In the file format conversion method of the present invention, when the plurality of marker segments are extracted in the extraction step and there are a plurality of DQT or DHT marker segments in the plurality of marker segments, the plurality of DQTs present Or it includes what has a marker segment synthesis | combination step which synthesize | combines each marker segment of DHT into one.

  According to this configuration, even when there are a plurality of marker segments in a plurality of marker segments of a JFIF image, the JFIF image can be converted into an EXIF image as in the case where one marker segment exists. it can.

  According to the file format conversion apparatus, the file format conversion method, and the program used for the file format conversion apparatus of the present invention, the time required for converting the JFIF image and generating the EXIF image can be reliably reproduced. EXIF images can be generated.

  Hereinafter, a file format conversion apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration diagram of a file format conversion apparatus according to an embodiment of the present invention, and FIG. 2 shows a format configuration diagram (a) of a JFIF image and a format configuration diagram (b) of an EXIF image.

  The image file input unit 101 of the file format conversion apparatus has information about APP0 having related information about compressed image data, DQT having information about a quantization table, and Huffman table, as shown in FIG. Inputs a JFIF image having a format composed of DHT, DRI having information about a restart interval, SOF having information about a frame header, SOS having information about a scan header, and compressed image data Then, the JPEG marker segment extraction unit 102 extracts parameters stored in the marker segments DQT, DHT, DRI, SOF, and SOS except APP0 from the input JFIF image, and the compressed image data extraction unit 103 inputs the parameters. JFIF It extracts the compressed image data from.

  Of the marker segments of the JFIF image, DQT or DHT may be composed of a plurality of marker segments (corresponding to DQT (Option 1) or DHT (Option 1) in FIG. 3). The number of marker segments of DQT (Option 1) or DHT (Option 1) is arbitrarily set when generating a JFIF image before inputting the JFIF image to the file format conversion device. When the DQT or DHT is composed of a plurality of marker segments, the JPEG marker segment extraction unit 102 extracts parameters stored in the plurality of marker segments DQT or the plurality of marker segments DHT, respectively. Further, the DRI (Option 2) in the marker segment of the JFIF image may not exist depending on the JFIF image. The presence / absence of this DRI (Option 2) is set when a JFIF image is generated before the JFIF image is input to the file format conversion apparatus. If there is a DRI, the JPEG marker segment extraction unit 102 extracts a parameter stored in the DRI.

  The JPEG marker segment determination unit 104 determines whether to recompress or not recompress the JFIF image file input to the image file input unit 101 based on the parameter of each marker segment extracted by the JPEG marker segment extraction unit 102. . Table 1 shows determination conditions for non-recompression at this time.

  The JPEG marker segment determination unit 104 performs determination based on the determination conditions shown in Table 1 for each marker segment parameter of the JFIF image, and when all the parameters of each marker segment satisfy the non-recompression condition, It is determined that the JFIF image file input to the file input unit 101 is not recompressed.

  The APP1 generation unit 108 generates APP1 based on the tag information related to the compressed image data of the JFIF image, information including the thumbnail, and the header.

  When the DQT is composed of a plurality of marker segments, the DQT marker segment combining unit 106 generates a single DQT parameter by combining the DQTs of the plurality of marker segments input from the JPEG marker segment determination unit 104. In addition, when the DHT is composed of a plurality of marker segments, the DHT marker segment synthesizing unit 107 synthesizes the DHT of the plurality of marker segments input from the JPEG marker segment determination unit 104 to generate one DHT parameter.

  The EXIF generation unit 109 determines that the JPEG marker segment determination unit 104 determines not to recompress, and if the DQT and DHT are configured by one marker segment, the EXIF generation unit 109 inputs the JFIF image input from the JPEG marker segment determination unit 104. The parameters of each marker segment excluding APP0 and the compressed image data input from the compressed image data extraction unit 103 are diverted according to the format correspondence relationship between the JFIF image and the EXIF image without recompression shown in FIG. The APP1 parameters generated by the generation unit 108 are combined to generate an EXIF image. The EXIF generation unit 109 diverts the DRI of the JFIF image to the DRI of the EXIF image if the DRI exists in the JFIF image, but does not generate the DRI in the EXIF image if the DRI does not exist in the JFIF image.

  If the JPEG marker segment determination unit 104 determines that the JPEG marker segment determination unit 104 does not recompress and the DQT or DHT is composed of a plurality of marker segments, the EXIF generation unit 109 inputs the JFIF image input from the JPEG marker segment determination unit 104 DRI, SOF, and SOS parameters among the marker segments, DQT parameters input from the JPEG marker segment determination unit 104 or DQT marker segment synthesis unit 106, and input from the JPEG marker segment determination unit 104 or DHT marker segment synthesis unit 107 The DHT parameters and the compressed image data input from the compressed image data extraction unit 103 are used, and the APP1 generated by the APP1 generation unit 108 is combined to generate an EXIF image. The EXIF generation unit 109 diverts the DRI of the JFIF image to the DRI of the EXIF image if the DRI exists in the JFIF image, but does not generate the DRI in the EXIF image if the DRI does not exist in the JFIF image.

  FIG. 4 shows the format correspondence between the JFIF image and the EXIF image when recompressing. When the JPEG marker segment determination unit 104 determines to recompress, the JPEG recompression unit 105 performs compression using the compressed image data input from the compressed image data extraction unit 103 and the marker segment input from the JPEG marker segment determination unit 104. The image is expanded, the expanded image data is compressed using each marker segment having parameters satisfying the non-recompressing condition in the JPEG marker segment determination unit 104, and output to the EXIF generation unit 109. The EXIF generation unit 109 combines the APP1 input from the APP1 generation unit 108 to generate an EXIF image.

  The image file output unit 110 outputs the EXIF image generated by the EXIF generation unit 109 to the outside.

  FIG. 5 shows a processing flow at the time of non-recompression / recompression determination in the file format conversion apparatus according to the embodiment of the present invention. When a JFIF image is input to the image file input unit 101 of the file format conversion apparatus, the JPEG marker segment extraction unit 102 extracts parameters stored in each marker segment excluding APP0 from the input JFIF image (S501). The JPEG marker segment determination unit 104 performs determination based on the determination conditions shown in Table 1 for each of the marker segment excluding APP0 of the JFIF image, DQT, DHT, DRI, SOF, and SOS (S502 to S506). When it is determined that all the marker segment parameters satisfy the non-recompression condition (S502 to S506, all YES), an EXIF image is generated without recompressing the JFIF image file input to the image file input unit 101. The process proceeds to processing (S507). On the other hand, when the JPEG marker segment determination unit 104 determines that any one of the marker segments of the JFIF image, DQT, DHT, DRI, SOF, and SOS does not satisfy the non-recompression condition (S502 to S506, either NO), the process proceeds to a process of generating an EXIF image by recompressing the JFIF image file input to the image file input unit 101 (S508).

  FIG. 6 shows a processing flow when generating an EXIF image in the file format conversion apparatus according to the embodiment of the present invention. 6A shows a processing flow for generating an EXIF image without recompression in step 507 of FIG. 5, and FIG. 6B shows an EXIF image generated by recompression in step 508 of FIG. The processing flow to be performed is shown respectively.

  In the case of generating an EXIF image without recompression in FIG. 6A, when the generation of the EXIF image is started, the JPEG marker segment determination unit 104 stores the marker segment DQT of the JFIF image in a plurality of marker segments. If it is stored in a plurality of marker segments (S601, YES), the DQT parameters stored in the plurality of marker segments are input to the DQT marker segment combining unit 106. The DQT marker segment synthesizing unit 106 synthesizes the DQT parameters stored in the plurality of marker segments into one DQT parameter (S602), and outputs it to the EXIF generating unit 109. Further, the JPEG marker segment determination unit 104 determines whether or not the marker segment DHT of the JFIF image is stored in a plurality of marker segments (S603), and if stored in the plurality of marker segments (S603, YES), The DHT parameters stored in the plurality of marker segments are input to the DHT marker segment combining unit 107. The DHT marker segment synthesizer 107 synthesizes the DHT parameters stored in the plurality of marker segments into one DHT parameter (S604), and outputs it to the EXIF generator 109. If the marker segment DQT or DHT of the JFIF image is stored in one marker segment (S601 or S603, NO), the JPEG marker segment determination unit 104 outputs the DQT parameter or the DHT parameter as it is to the EXIF generation unit 109. To do.

  The compressed image data extraction unit 103 outputs the compressed image data extracted from the JFIF image to the EXIF generation unit 109 (S605), and the APP1 generation unit 108 outputs the generated APP1 parameter to the EXIF generation unit 109 (S606).

  The EXIF generation unit 109 includes the DRI, SOF, and SOS parameters input from the JPEG marker segment determination unit 104, the DQT parameter input from the JPEG marker segment determination unit 104 or the DQT marker segment synthesis unit 106, the JPEG marker segment determination unit 104, or the DHT marker. The DHT parameter input from the segment combining means 107, the compressed image data input from the compressed image data extraction unit 103, and the APP1 parameter input from the APP1 generation unit 108 are combined to generate an EXIF image (S607).

  Next, in the case of generating an EXIF image by recompressing in FIG. 6B, when the generation of the EXIF image is started, the JPEG marker segment determination unit 104 compresses the parameters stored in each marker segment except APP0. The image data extraction unit 103 outputs the compressed image data of the JFIF image to the JPEG recompression unit 105, respectively. The JPEG recompression unit 105 expands a compressed image using the input compressed image data and the marker segment input from the JPEG marker segment determination unit 104, and sets parameters satisfying the non-recompression condition in the JPEG marker segment determination unit 104. The developed image data is compressed using each marker segment, and is output to the EXIF generation unit 109 (S651). The APP1 generation unit 108 outputs the generated APP1 parameter to the EXIF generation unit 109 (S652).

  The EXIF generation unit 109 combines the recompressed data input from the JPEG recompression unit 105 and the APP1 parameter input from the APP1 generation unit 108 to generate an EXIF image (S653).

  As described above, according to the file format conversion apparatus of the embodiment of the present invention, it is possible to generate an EXIF image that is reliably reproduced while reducing the time required to convert the JFIF image to generate the EXIF image. .

  The file format conversion apparatus, the file format conversion method, and the program used in the file format conversion apparatus according to the present invention can be reliably reproduced while reducing the time required to convert the JFIF image and generate the EXIF image. This produces an effect that an image can be generated, and is useful in the field of converting an image whose file format is configured by JFIF into an image configured by EXIF.

Configuration diagram of a file format conversion apparatus according to an embodiment of the present invention Format configuration diagram of JFIF image (a) and format configuration diagram of EXIF image (b) Format correspondence between JFIF images and EXIF images without recompression Format correspondence between JFIF images and EXIF images when recompressing Processing flow at the time of non-recompression / recompression determination in the file format conversion apparatus according to the embodiment of the present invention In the file format conversion apparatus according to the embodiment of the present invention, a processing flow (a) when generating an EXIF image without recompression and a processing flow (b) when generating an EXIF image by recompression Configuration diagram of converted image file in image file format conversion apparatus of Patent Document 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image file input part 102 JPEG marker segment extraction part 103 Compressed image data extraction part 104 JPEG marker segment determination part 105 JPEG recompression part 106 DQT marker segment composition part 107 DHT marker segment composition part 108 APP1 generation part 109 EXIF generation part 110 Image File output section

Claims (5)

A file format conversion device for converting a JFIF image file including a plurality of marker segments and compressed image data into an EXIF image file,
An input means for inputting the JFIF image file;
Extraction means for extracting the plurality of marker segments and the compressed image data from the input JFIF image file;
Determining means for determining whether or not to recompress the input JFIF image file based on parameters stored in each of the extracted marker segments;
If it is determined to recompress, the image data expanded from the compressed state is recompressed to generate an EXIF image file. If it is determined not to recompress, the extracted marker segments and the extracted compressed image Generating means for generating an EXIF image file by diverting data;
An output means for outputting the generated EXIF image file;
A file format conversion device comprising: The file format conversion device according to claim 1,
A file format conversion device comprising marker segment synthesizing means for synthesizing each of the plurality of DQT or DHT marker segments into one when there are a plurality of DQT or DHT marker segments in the plurality of marker segments. A file format conversion method for converting a JFIF image file including a plurality of marker segments and compressed image data into an EXIF image file,
An input step of inputting the JFIF image file;
An extraction step of extracting the plurality of marker segments and the compressed image data from the input JFIF image file;
A determination step of determining whether to re-compress the input JFIF image file based on parameters stored in each of the extracted marker segments;
If it is determined to recompress, the image data expanded from the compressed state is recompressed to generate an EXIF image file. If it is determined not to recompress, the extracted marker segments and the extracted compressed image A generation step of generating an EXIF image file by using the data,
An output step of outputting the generated EXIF image file;
A file format conversion method comprising: The file format conversion method according to claim 3, wherein
After extracting the plurality of marker segments in the extraction step, if there are a plurality of DQT or DHT marker segments in the plurality of marker segments, the plurality of DQT or DHT marker segments are combined into one each. A file format conversion method comprising a marker segment synthesis step.   The program for making a computer perform each step of Claim 3 or 4.

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