JP2004236226A - Method and apparatus for image decompressing, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image decompressing method capable of dealing with decompressing a compressed code which have been compressed by various image standards, even if the image file does not have image data of a plurality of image formats. <P>SOLUTION: When it is determined that the compressed codes to be decompressed is of a new image standard which cannot be decompressed by the existing decoding program on the basis of code-relating information managed by a marker segment (Y in S2), a decoding program corresponding to the new image standard is obtained (S3) according to the program location information indicating the location of the decoding program for applying decompression to the compressed codes included in the code-related information, and the compressed codes compressed by the new image standard are decompressed by using the decoding program corresponding to the obtained new image standard (S4). In this way, the decompression of the compressed codes compressed by various image standards can be dealt with, even if the image file does not have image data of a plurality of image formats. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image decompression method, an image decompression device, a program, and a storage medium.
[0002]
[Prior art]
2. Description of the Related Art Due to advances in image input technology and output technology thereof, demands for higher definition of images have been extremely increased in recent years. For example, taking a digital camera (Digital Camera) as an example of an image input device, the price of a high-performance charge coupled device (CCD: Charge Coupled Device) having more than 3 million pixels has been reduced, and the price range has become widespread. Products have come to be widely used. And a product with 5 million pixels is coming soon. It is said that this increasing tendency of the number of pixels will continue for a while.
[0003]
On the other hand, with regard to image output / display devices, for example, products in the hard copy field such as laser printers, ink jet printers and sublimation printers, and flat devices such as CRTs, LCDs (liquid crystal display devices), and PDPs (plasma display devices). The high definition and low price of products in the field of soft copy of panel displays are remarkable.
[0004]
Due to the effect of bringing high-performance, low-cost image input / output products to the market, the popularization of high-definition images has begun, and it is expected that demand for high-definition images will increase in all scenes in the future. Indeed, the development of technologies related to networks, such as personal computers and the Internet, is accelerating these trends. In particular, recently, mobile devices such as mobile phones and notebook personal computers have become very popular, and opportunities to transmit or receive high-definition images from any point using communication means have been rapidly increasing.
[0005]
Against this background, the demand for higher performance or multifunctional image compression / decompression technology that facilitates the handling of high-definition images will inevitably increase in the future.
[0006]
Therefore, in recent years, a new method called JPEG2000, which can restore a high-quality image even at a high compression ratio, is being standardized as one of the image compression methods satisfying such demands. In JPEG2000, by dividing an image into rectangular areas (tiles), it is possible to perform compression / expansion processing in a small memory environment. That is, each tile is a basic unit when executing the compression / decompression process, and the compression / decompression operation can be performed independently for each tile.
[0007]
However, an apparatus having no means for expanding image data compressed and encoded by the new method of JPEG2000 cannot display an image compressed and encoded by the JPEG2000 method.
[0008]
If the version of the image data is different even if the image data is compressed and encoded by the JPEG2000 system, the image data compressed and encoded by the new version of the JPEG2000 system may be used in an apparatus that supports only the old version of the JPEG2000 system. May not be displayed.
[0009]
In order to solve such a problem, a method in which one image file has two image formats has been proposed. More specifically, by including a JPEG image in a JPEG2000 image file, an image can be displayed even on a terminal having no JPEG2000 decoding function (for example, see Patent Document 1).
[0010]
[Patent Document 1]
JP-A-2002-44663
[0011]
[Problems to be solved by the invention]
However, according to the technique proposed in Patent Document 1, since one image file has image data of two image formats (JPEG2000 image format and JPEG image format), a large amount of memory capacity is consumed. There is a problem.
[0012]
An object of the present invention is to provide an image decompression method and an image decompression method capable of coping with decompression processing of a compression code compressed by various image standards without having image data of a plurality of image formats in one image file. An object of the present invention is to provide a decompression device, a program, and a storage medium.
[0013]
[Means for Solving the Problems]
An image decompression method according to the first aspect of the present invention is an image decompression method for decompressing a compressed code obtained by encoding an image by using a decoding program, wherein the compression code is decompressed at least when the compressed code is compressed. Managing the code-related information including the program location information indicating the location of the decoding program in a predetermined marker segment defined by a code format; and a method in which the compressed code to be expanded cannot be expanded by the existing decoding program. Determining whether or not the image standard is based on the code-related information managed by the marker segment; and, when the compressed code is determined to be a new image standard, managing by the marker segment. According to the program location information included in the code-related information, Including by obtaining a decoding program, a step of extending said compressed code is a new image standards using the decoding program corresponding to the acquired new image standard,.
[0014]
Therefore, when it is determined based on the code-related information managed by the marker segment that the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program, it is included in the code-related information. According to the program location information indicating the location of the decoding program for decompressing the compression code, a decoding program corresponding to the new image standard is obtained, and a new image is generated using the obtained decoding program corresponding to the new image standard. A compression code compressed according to the standard is decompressed. This makes it possible to decompress a compressed code compressed by a new image standard that cannot be decompressed by an existing decoding program after obtaining a decoding program corresponding to the new image standard. Even if one image file does not have image data of a plurality of image formats, it is possible to cope with the decompression processing of a compression code compressed by various image standards.
[0015]
According to a second aspect of the present invention, in the image decompression method according to the first aspect, the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker.
[0016]
Therefore, it is possible to maintain the compatibility of the files, and to have versatility.
[0017]
According to a third aspect of the present invention, in the image decompression method according to the first or second aspect, the program location information is a URL (Uniform Resource) that specifies a decoding program corresponding to a new image standard stored in a program storage device. Locator).
[0018]
Therefore, it is possible to execute the decompression process using the latest version of the decoding program while the size of the image file is substantially the same as the size of the original image file.
[0019]
According to a fourth aspect of the present invention, in the image decompression apparatus, code-related information which is a compression code obtained by encoding an image and includes at least a program location information indicating a location of a decoding program for decompressing the compression code is encoded. In an image decompression device that decompresses the compressed code managed by the predetermined marker segment specified in the above using a decoding program, the decompression target compressed code is a new image standard that cannot be decompressed by the existing decoding program. An image standard determining unit that determines whether or not the compressed code is a new image standard based on the code related information managed in the marker segment; According to the program location information included in the code related information, Program acquisition means for acquiring a code program from a program storage device connected via a network, and image decompression means for decompressing the compression code, which is a new image standard, using a decoding program corresponding to the acquired new image standard And.
[0020]
Therefore, when it is determined based on the code-related information managed by the marker segment that the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program, it is included in the code-related information. According to the program location information indicating the location of the decoding program for decompressing the compression code, a decoding program corresponding to the new image standard is acquired from a program storage device connected via a network, and the acquired new image standard is acquired. The compressed code compressed according to the new image standard is expanded by using a decoding program corresponding to. This makes it possible to decompress a compressed code compressed by a new image standard that cannot be decompressed by an existing decoding program after obtaining a decoding program corresponding to the new image standard. Even if one image file does not have image data of a plurality of image formats, it is possible to cope with the decompression processing of a compression code compressed by various image standards.
[0021]
According to a fifth aspect of the present invention, in the image decompression apparatus according to the fourth aspect, the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker.
[0022]
Therefore, it is possible to maintain the compatibility of the files, and to have versatility.
[0023]
According to a sixth aspect of the present invention, in the image decompression apparatus according to the fourth or fifth aspect, the program location information is a URL (Uniform Resource) that specifies a decoding program corresponding to a new image standard stored in a program storage device. Locator).
[0024]
Therefore, it is possible to execute the decompression process using the latest version of the decoding program while the size of the image file is substantially the same as the size of the original image file.
[0025]
According to a seventh aspect of the present invention, there is provided a program for specifying, in a code format, code-related information that is a compressed code obtained by encoding an image and includes program location information indicating at least the location of a decoding program for decompressing the compressed code. A program installed or interpreted and executed in a computer of an image decompression device that decompresses the compressed code managed by the predetermined marker segment by using a decoding program, and An image standard judging function for judging whether or not a code is a new image standard which cannot be decompressed by the existing decoding program based on the code related information managed by the marker segment; and If it is determined to be a standard, it is managed by the marker segment In accordance with the program location information included in the code-related information, a program acquisition function for acquiring a decoding program corresponding to a new image standard from a program storage device connected via a network, and a function corresponding to the acquired new image standard. An image decompression function for decompressing the compression code, which is a new image standard, using a decoding program is executed by the computer.
[0026]
Therefore, when it is determined based on the code-related information managed by the marker segment that the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program, it is included in the code-related information. According to the program location information indicating the location of the decoding program for decompressing the compression code, a decoding program corresponding to the new image standard is acquired from a program storage device connected via a network, and the acquired new image standard is acquired. The compressed code compressed according to the new image standard is expanded by using a decoding program corresponding to. This makes it possible to decompress a compressed code compressed by a new image standard that cannot be decompressed by an existing decoding program after obtaining a decoding program corresponding to the new image standard. Even if one image file does not have image data of a plurality of image formats, it is possible to cope with the decompression processing of a compression code compressed by various image standards.
[0027]
The storage medium according to the invention of claim 8 is a storage medium in which code-related information, which is a compression code obtained by encoding an image and includes program location information indicating at least the location of a decoding program for decompressing the compression code, is stored in a code format. A storage medium that stores a program that is installed in a computer of an image decompression device that decompresses the compression code managed by a prescribed marker segment using a decoding program or that is interpreted and executed. An image standard determination function for determining whether or not the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program, based on the code related information managed in the marker segment; If the compression code is determined to be a new image standard, the marker segment A program acquisition function of acquiring a decoding program corresponding to a new image standard from a program storage device connected via a network in accordance with the program location information included in the managed code-related information; and a new acquired image. A program for causing the computer to execute an image decompression function of decompressing the compression code, which is a new image standard, using a decoding program corresponding to the standard is stored.
[0028]
Therefore, when it is determined based on the code-related information managed by the marker segment that the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program, it is included in the code-related information. According to the program location information indicating the location of the decoding program for decompressing the compression code, a decoding program corresponding to the new image standard is acquired from a program storage device connected via a network, and the acquired new image standard is acquired. The compressed code compressed according to the new image standard is expanded by using a decoding program corresponding to. This makes it possible to decompress a compressed code compressed by a new image standard that cannot be decompressed by an existing decoding program after obtaining a decoding program corresponding to the new image standard. Even if one image file does not have image data of a plurality of image formats, it is possible to cope with the decompression processing of a compression code compressed by various image standards.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
First, an overview of the “hierarchical encoding algorithm” and the “JPEG2000 algorithm” which are the premise of the present embodiment will be described.
[0030]
FIG. 1 is a functional block diagram of a system for realizing a hierarchical coding algorithm which is a basic of the JPEG2000 system. This system includes a color space conversion / inverse transformation unit 101, a two-dimensional wavelet transformation / inverse transformation unit 102, a quantization / inverse quantization unit 103, an entropy coding / decoding unit 104, and a tag processing unit 105. It is configured.
[0031]
One of the biggest differences between this system and the conventional JPEG algorithm is the conversion method. In JPEG, discrete cosine transform (DCT: Discrete Cosine Transform) is used, whereas in the hierarchical coding algorithm, a two-dimensional wavelet transform / inverse transform unit 102 uses discrete wavelet transform (DWT: Discrete Wavelet Transform). ing. DWT has an advantage that the image quality in a high compression area is better than DCT, and this is one of the main reasons why DWT was adopted in JPEG2000 which is a successor algorithm of JPEG.
[0032]
Another major difference is that in the hierarchical coding algorithm, a functional block of the tag processing unit 105 is added in order to form a code at the last stage of the system. The tag processing unit 105 generates compressed data as code string data at the time of image compression operation, and interprets code string data required for decompression at the time of decompression operation. The JPEG2000 can realize various convenient functions by using the code string data. For example, the compression / expansion operation of a still image can be freely stopped at an arbitrary layer (decomposition level) corresponding to octave division in a DWT on a block basis (see FIG. 3 described later).
[0033]
In many cases, a color space conversion / inverse conversion 101 is connected to the input / output portion of the original image. For example, an RGB color system composed of R (red) / G (green) / B (blue) components of a primary color system, and Y (yellow) / M (magenta) / C (cyan) components of a complementary color system The conversion or inverse conversion from the YMC color system to the YUV or YCbCr color system corresponds to this.
[0034]
Next, the JPEG2000 algorithm will be described.
[0035]
Generally, in a color image, as shown in FIG. 2, each component 111 (here, the RGB primary color system) of the original image is divided by a rectangular area. The divided rectangular area is generally called a block or a tile. In JPEG2000, it is generally called a tile. Hereinafter, such a divided rectangular area is referred to as a tile. (In the example of FIG. 2, each component 111 is divided into a total of 16 rectangular tiles 112, 4 × 4 vertically and horizontally.) When such individual tiles 112 (in the example of FIG. 2, R00, R01,..., R15 / G00, G01,..., G15 / B00, B01,. Is the basic unit of Therefore, the compression / decompression operation of the image data is performed independently for each component and for each tile 112.
[0036]
At the time of encoding image data, the data of each tile 112 of each component 111 is input to the color space conversion / inverse conversion unit 101 of FIG. 1 and subjected to color space conversion. A dimensional wavelet transform (forward transform) is performed, and spatial division into frequency bands is performed.
[0037]
FIG. 3 shows subbands at each decomposition level when the number of decomposition levels is three. That is, a two-dimensional wavelet transform is performed on the tile original image (0LL) (decomposition level 0) obtained by dividing the original image into tiles, and the subbands (1LL, 1HL, 1LH) indicated by the decomposition level 1 are obtained. , 1HH). Subsequently, two-dimensional wavelet transform is performed on the low-frequency component 1LL in this layer to separate the subbands (2LL, 2HL, 2LH, 2HH) shown in the decomposition level 2. Similarly, two-dimensional wavelet transform is performed on the low-frequency component 2LL in the same manner to separate the sub-bands (3LL, 3HL, 3LH, 3HH) shown in the decomposition level 3. In FIG. 3, the subbands to be coded at each decomposition level are shaded. For example, when the number of decomposition levels is 3, the subbands (3HL, 3LH, 3HH, 2HL, 2LH, 2HH, 1HL, 1LH, 1HH) indicated by shading are to be encoded, and the 3LL subbands are encoded. Is not converted.
[0038]
Next, bits to be encoded are determined in the designated order of encoding, and the quantization / inverse quantization unit 103 shown in FIG. 1 generates a context from bits around the target bits.
[0039]
The wavelet coefficients after the quantization process are divided into non-overlapping rectangles called “precincts” for each subband. This was introduced to make efficient use of memory in the implementation. As shown in FIG. 4, one precinct is formed of three spatially coincident rectangular areas. Further, each precinct is divided into non-overlapping rectangular "code blocks". This is a basic unit when performing entropy coding.
[0040]
The coefficient value after wavelet transform can be quantized and encoded as it is. However, in JPEG2000, in order to increase the encoding efficiency, the coefficient value is decomposed into “bit plane” units, and each pixel or code block is decomposed. "Bit planes" can be ranked.
[0041]
Here, FIG. 5 is an explanatory diagram showing an example of a procedure for prioritizing bit planes. As shown in FIG. 5, in this example, the original image (32 × 32 pixels) is divided into four 16 × 16 pixel tiles, and the size of the precinct of the decomposition level 1 and the size of the code block are as follows. Each has 8 × 8 pixels and 4 × 4 pixels. The numbers of precincts and code blocks are assigned in raster order. In this example, the precincts are assigned numbers 0 to 3, and the code blocks are assigned numbers 0 to 3. The pixel expansion outside the tile boundary is performed by using a mirroring method, performing a wavelet transform using a reversible (5, 3) filter, and obtaining a wavelet coefficient value of decomposition level 1.
[0042]
FIG. 5 also shows an explanatory diagram showing an example of a typical “layer” configuration concept of tile 0 / precinct 3 / code block 3. The converted code block is divided into subbands (1LL, 1HL, 1LH, 1HH), and each subband is assigned a wavelet coefficient value.
[0043]
The layer structure is easy to understand when the wavelet coefficient value is viewed from the horizontal direction (bit plane direction). One layer is composed of an arbitrary number of bit planes. In this example, layers 0, 1, 2, and 3 are made up of 1, 3, 1, and 3 bit planes, respectively. A layer including a bit plane closer to LSB (Least Significant Bit: Least Significant Bit) is subject to quantization first, and conversely, a layer closer to MSB (Most Significant Bit: Most Significant Bit) is quantized to the end. It will remain without being. A method of discarding from a layer close to the LSB is called truncation, and it is possible to finely control the quantization rate. The process of discarding a code from a code in which a bit plane (or a sub-bit plane) is not deleted until a predetermined compression rate is obtained is called post-quantization, and is the most significant feature of the JPEG2000 algorithm. .
[0044]
The entropy encoding / decoding unit 104 shown in FIG. 1 performs encoding on the tile 112 of each component 111 by probability estimation from the context and the target bit. In this way, the encoding process is performed on all the components 111 of the original image in tile 112 units. Finally, the tag processing unit 105 performs a process of combining all the encoded data from the entropy encoding / decoding unit 104 into one piece of code string data (code stream) and adding a tag thereto.
[0045]
On the other hand, at the time of decoding, the image data is generated from the code string data of each tile 112 of each component 111, contrary to the case of encoding the image data. In this case, the tag processing unit 105 interprets the tag information added to the code string data input from the outside, decomposes the code string data into code string data of each tile 112 of each component 111, and A decoding process (decompression process) is performed for each code string data of each tile 112. At this time, the positions of the bits to be decoded are determined in the order based on the tag information in the code string data, and the quantization / dequantization unit 103 sets the peripheral bits of the target bit position (the A context is generated from the sequence of (finished). The entropy coding / decoding unit 104 performs decoding by probability estimation from the context and the code string data, generates a target bit, and writes it to the position of the target bit. Since the data decoded in this way is spatially divided for each frequency band, the two-dimensional wavelet transform / inverse transform unit 102 performs an inverse two-dimensional wavelet transform on the data to obtain each component of the image data. The tile is restored. The restored data is converted by the color space conversion / inverse conversion unit 101 into the original color system image data.
[0046]
The above is the outline of the “JPEG2000 algorithm”.
[0047]
Hereinafter, an embodiment of the present invention will be described. Here, an example relating to an image compression / decompression technique represented by JPEG2000 will be described, but needless to say, the present invention is not limited to the content of the following description.
[0048]
FIG. 6 is a system configuration diagram showing a system including the image decompression device 1 to which the present invention is applied. As shown in FIG. 6, the image decompression device 1 to which the present invention is applied is, for example, a personal computer, and can be connected to a server computer S that stores and holds various image data via a network 5 that is the Internet. . The server computer S also functions as a program storage device that stores a decoding program described later.
[0049]
In the present embodiment, the image data stored and held in the server computer S is a compression code generated according to the “JPEG2000 algorithm”. FIG. 7 shows a schematic configuration of a JPEG2000 code format. The code format starts with an SOC (Start of Codestream) marker indicating the start of the code data. After the SOC marker, a main header (Main Header), which is tag information describing coding parameters and quantization parameters, follows, followed by actual code data. Actual code data starts with an SOT (Start of Tile-part) marker, and includes a tile header (Tile Header) as tag information, a SOD (Start of data) marker, and tile data (code: bit stream). After the code data corresponding to the entire image, an EOC (End of Codestream) marker, which is tag information indicating the end of the code, is added. The main header and the tile header as described above may include a comment marker (COM marker) capable of describing code-related information related to the compression code.
[0050]
In the present embodiment, as shown in FIG. 8, the comment marker of the main header includes the image standard of the compression code, the version of the image standard, and the location of the decoding program for processing the compression code (here, In addition, code-related information related to the compression code, such as a URL (Uniform Resource Locator) of the WEB server where the decoding program is stored, a tool name (program name) that created the image, and a manufacturer name are described.
[0051]
FIG. 9 is a block diagram schematically illustrating a hardware configuration of the image decompression device 1. As shown in FIG. 9, the image decompression apparatus 1 includes a CPU (Central Processing Unit) 6 for performing information processing, a ROM (Read Only Memory) 7 for storing information, and a primary storage device such as a RAM (Random Access Memory) 8. A hard disk drive (HDD) 10, which is a storage unit for storing a compression code (see FIG. 7) downloaded from the server computer S via the network 5, storing information, distributing information to the outside, and obtaining information from the outside CD-ROM drive 12, a communication control device 13 for transmitting information to another external computer via the network 5, and a CRT (Cathode Ray Tube) for displaying the progress and results of processing to the operator. And LCD (Liquid C A display 15 such as an external display, and an input device 14 such as a keyboard and a mouse for the operator to input commands, information, and the like to the CPU 6. The data transmitted and received between these units is transmitted via a bus. The controller 9 operates by arbitration.
[0052]
Since the RAM 8 has a property of storing various data in a rewritable manner, the RAM 8 functions as a work area of the CPU 6 and plays a role of, for example, a buffer memory in an image display process described later.
[0053]
In such an image decompression apparatus 1, when the user turns on the power, the CPU 6 activates a program called a loader in the ROM 7, reads a program called an operating system, which manages computer hardware and software, from the HDD 10 into the RAM 8, and executes the operating system. Start the system. Such an operating system starts a program, reads information, and saves information in response to a user operation. As typical operating systems, Windows (registered trademark), UNIX (registered trademark), and the like are known. The operation programs running on these operating systems are called application programs.
[0054]
Here, the image decompression device 1 stores an image processing program including a decode program in the HDD 10 as an application program. In this sense, the HDD 10 functions as a storage medium for storing a program.
[0055]
In general, an operation program installed in the HDD 10 of the image decompression apparatus 1 is recorded on an optical information recording medium such as a CD-ROM 11 or a DVD-ROM, or a magnetic medium such as an FD, and the recorded operation program. The program is installed on the HDD 10. Therefore, a portable storage medium such as an optical information recording medium such as the CD-ROM 11 or a magnetic medium such as an FD can be a storage medium for storing the image processing program. Further, the image processing program may be fetched from outside via the communication control device 13 and installed in the HDD 10, for example.
[0056]
In the image decompression apparatus 1, when an image processing program running on an operating system is started, the CPU 6 executes various arithmetic processes according to the image processing program to centrally control each unit. Among the various types of arithmetic processing executed by the CPU 6 of the image decompression device 1, the characteristic processing of the present embodiment will be described below.
[0057]
Here, among the image display processes executed by the CPU 6 according to the image processing program, an image display process using code related information related to a compression code described in a comment marker will be described. FIG. 10 is a flowchart schematically showing the flow of the image display processing. As shown in FIG. 10, when the CPU 6 of the image decompression apparatus 1 obtains a compression code related to an image file from the server computer S via the network 5 (Y in step S1), a comment is issued as to whether or not the image standard is new. The determination is made based on the image standard of the compression code, which is the code-related information described in the marker (step S2: image standard determination means).
[0058]
If the acquired compression code does not conform to the new image standard (N in step S2), the process directly proceeds to step S4, where the compression code is subjected to a decompression process (decoding process) according to the “JPEG2000 algorithm” and displayed. It is displayed on the device 15. Here, the function of the image decompression means is executed. Regarding the decompression process (decoding process) of the compression code according to the “JPEG2000 algorithm”, the spatial transform / inverse transform unit 101, the two-dimensional wavelet transform / inverse transform unit 102, and the quantization / inverse quantize unit 103 shown in FIG. , The entropy encoding / decoding unit 104 and the tag processing unit 105 have been described above, and a description thereof will be omitted.
[0059]
On the other hand, if the acquired compression code is a new image standard (Y in step S2), the process proceeds to step S3. Here, when the acquired compression code is a new image standard, the version of “JPEG2000” is new, and the decoding program installed in the HDD 10 of the image decompression device 1 corresponds to this version of “JPEG2000”. There may be no case.
[0060]
Here, the program acquisition process in step S3 will be described with reference to FIG. If the acquired compression code is a new image standard (Y in step S2), the CPU 6 of the image decompression apparatus 1 accesses the URL described in the comment marker via the network 5. Here, the URL described in the comment marker indicates the location of a decoding program for processing the compression code, and it is assumed that the web server storing the decoding program is the server computer S.
[0061]
When the access to the server computer S is established, the CPU 6 of the image decompression apparatus 1 transmits the image standard of the compression code described in the comment marker and the version of the image standard to the server computer S via the network 5. I do.
[0062]
The server computer S that has received the image standard of the compression code and the version of the image standard from the image decompression device 1 transmits the corresponding decoding program to the image decompression device 1 via the network 5.
[0063]
Then, the CPU 6 of the image decompression device 1 downloads the decoding program (applet or EXE file) transmitted from the server computer S. As a result, the decoding program installed in the HDD 10 of the image decompression device 1 corresponds to the new version of “JPEG2000”.
[0064]
With the above, the program acquisition processing in step S3 ends. Here, the function of the program acquisition means is executed.
[0065]
Subsequently, the process proceeds to step S4, where the acquired compression code is subjected to a decompression process (decoding process) based on a decoding program corresponding to the new version of “JPEG2000”, and displayed on the display device 15.
[0066]
Here, if it is determined based on the code related information managed by the marker segment that the compressed code to be expanded is a new image standard that cannot be expanded by the existing decoding program, it is included in the code related information. In accordance with the program location information indicating the location of the decoding program for expanding the compression code, a decoding program corresponding to the new image standard is obtained from the server computer S which is a program storage device connected via the network 5. Then, the compressed code compressed by the new image standard is decompressed by using the acquired decoding program corresponding to the new image standard. Thus, for a compressed code compressed by a new image standard that cannot be decompressed by an existing decoding program, a decoding program corresponding to the new image standard can be obtained and then the compressed code can be decompressed. Even if one image file does not have image data of a plurality of image formats, it is possible to cope with the decompression processing of a compression code compressed according to various image standards.
[0067]
Further, the program location information is a URL for specifying a decoding program corresponding to a new image standard stored in the server computer S as a program storage device, so that the size of the image file is equal to the size of the original image file. Decompression processing can be executed using the latest version of the decoding program while having substantially the same size as.
[0068]
In the present embodiment, an example has been described in which the image decompression device 1 of the present invention is applied to a personal computer. However, the image decompression device 1 is applied to an information terminal device such as a personal digital assistant (PDA) and a mobile phone. You can also.
[0069]
【The invention's effect】
According to the image decompression method of the first aspect of the present invention, there is provided an image decompression method for decompressing a compressed code obtained by encoding an image by using a decoding program. Managing the code-related information including the program location information indicating the location of the decoding program to be performed using a predetermined marker segment defined in a code format, and the compression code to be expanded cannot be expanded by the existing decoding program. Determining whether or not the image code is a new image standard based on the code related information managed by the marker segment; and, if the compressed code is determined to be a new image standard, the marker segment A new image standard according to the program location information contained in the code-related information managed in Acquiring a decoding program corresponding to the new image standard, and decompressing the compression code which is a new image standard using the acquired decoding program corresponding to the new image standard. If it is determined by the decoding program based on the code-related information managed in the marker segment that the new image standard cannot be decompressed, the compression code included in the code-related information is decompressed. According to the program location information indicating the location of the decoding program, a decoding program corresponding to the new image standard is obtained according to the program location information, and the compressed code compressed according to the new image standard is decompressed using the obtained decoding program corresponding to the new image standard. This allows compression with new image standards that cannot be decompressed by existing decoding programs. The obtained compressed code can be decompressed after obtaining a decoding program corresponding to the new image standard, so that even if one image file does not have image data of a plurality of image formats, It is possible to cope with a decompression process of a compression code compressed by various image standards.
[0070]
According to the second aspect of the present invention, in the image decompression method according to the first aspect, the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker. Can be maintained, and versatility can be provided.
[0071]
According to a third aspect of the present invention, in the image decompression method according to the first or second aspect, the program location information includes a URL (URL) for specifying a decode program corresponding to a new image standard stored in a program storage device. By being a Uniform Resource Locator, the size of the image file is substantially the same as the size of the original image file, but the decompression process can be executed using the latest version of the decoding program.
[0072]
According to the image decompression device of the fourth aspect of the present invention, the code-related information including the program location information indicating the location of a decode program for decompressing the compressed code, which is a code obtained by encoding the image, is obtained. In an image decompression device that decompresses the compressed code managed by a predetermined marker segment defined by a code format using a decoding program, a new image in which the compressed code to be decompressed cannot be decompressed by an existing decoding program An image standard determining unit that determines whether or not the standard is based on the code related information managed by the marker segment; and, when the compressed code is determined to be a new image standard, According to the program location information included in the managed code related information, a new image standard Acquisition means for acquiring the obtained decoding program from a program storage device connected via a network, and image decompression for decompressing the compression code, which is a new image standard, using a decoding program corresponding to the obtained new image standard. Means for decompressing, when it is determined based on the code-related information managed in the marker segment that the compression code to be decompressed is a new image standard that cannot be decompressed by an existing decoding program, According to the program location information indicating the location of the decoding program for decompressing the compression code included in the information, the decoding program corresponding to the new image standard is obtained from the program storage device connected via the network, and the obtained decoding program is obtained. New using a decoding program that supports new image standards By decompressing a compression code compressed by an image standard, for a compression code compressed by a new image standard that cannot be decompressed by an existing decoding program, a decoding program corresponding to the new image standard is obtained and then Since the compression code can be expanded, it is possible to cope with expansion processing of a compression code compressed according to various image standards without having image data of a plurality of image formats in one image file.
[0073]
According to the fifth aspect of the present invention, in the image decompression apparatus according to the fourth aspect, the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker. Can be maintained, and versatility can be provided.
[0074]
According to a sixth aspect of the present invention, in the image decompression apparatus according to the fourth or fifth aspect, the program location information includes a URL (URL) for specifying a decoding program corresponding to a new image standard stored in a program storage device. By being a Uniform Resource Locator, the size of the image file is substantially the same as the size of the original image file, but the decompression process can be executed using the latest version of the decoding program.
[0075]
According to the program of the invention described in claim 7, code related information which is a compressed code obtained by encoding an image and includes program location information indicating at least the location of a decoding program for expanding the compressed code is encoded. A program that is installed or interpreted and executed on a computer of an image decompression device that decompresses the compressed code managed by a predetermined marker segment defined by An image standard judging function for judging whether or not the compressed code is a new image standard that cannot be decompressed by the existing decoding program based on the code related information managed by the marker segment; If it is determined that the image standard is the A program acquisition function for acquiring a decoding program corresponding to a new image standard from a program storage device connected via a network according to the program location information included in the code-related information, and supporting the acquired new image standard An image decompression function of decompressing the compression code, which is a new image standard, using the decoded program, and causing the computer to execute the decompression target compression code in a new image standard that cannot be decompressed by the existing decoding program. If it is determined based on the code-related information managed by the marker segment, a new location is determined according to the program location information indicating the location of the decode program for expanding the compressed code included in the code-related information. Decoding programs that support image standards via a network By using a decoding program corresponding to the new image standard obtained from the connected program storage device and expanding the compression code compressed according to the new image standard, a new code that cannot be expanded by the existing decoding program With regard to a compression code compressed according to the image standard of the above, it is possible to decompress the compression code after obtaining a decoding program corresponding to the new image standard, so that image data of a plurality of image formats can be stored in one image file. , It is possible to cope with decompression processing of a compression code compressed by various image standards.
[0076]
According to the storage medium of the eighth aspect of the present invention, the code-related information, which is a compression code obtained by encoding an image and includes program location information indicating at least the location of a decoding program for expanding the compression code, is encoded. A storage medium that stores a program that is installed in a computer of an image decompression device that decompresses the compressed code managed by a predetermined marker segment defined by a format using a decoding program, or that is interpreted and executed. An image standard determination function for determining whether or not the compressed code to be expanded is a new image standard that cannot be expanded by the existing decoding program based on the code related information managed in the marker segment; If the compression code is determined to be a new image standard, the marker segment A program acquisition function for acquiring a decoding program corresponding to a new image standard from a program storage device connected via a network in accordance with the program location information included in the code-related information managed by the client; An image decompression function of decompressing the compression code, which is a new image standard, using a decoding program corresponding to the image standard, and a program for causing the computer to execute the compression code. If it is determined based on the code-related information managed by the marker segment that the new image standard cannot be decompressed, the location of a decoding program for decompressing the compression code included in the code-related information is located. According to the program location information indicating the new An existing decoding program is obtained by acquiring a loaded program from a program storage device connected via a network, and decompressing a compressed code compressed according to the new image standard using a decoding program corresponding to the acquired new image standard. For a compressed code compressed by a new image standard that cannot be decompressed by a program, a decoding program corresponding to the new image standard can be acquired and then the compressed code can be decompressed. Even without having image data of a plurality of image formats, it is possible to cope with the expansion processing of a compression code compressed by various image standards.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a system for realizing a hierarchical coding algorithm which is a basis of the JPEG2000 system on which the present invention is based.
FIG. 2 is an explanatory diagram showing a divided rectangular area of each component of an original image.
FIG. 3 is an explanatory diagram showing subbands at each decomposition level when the number of decomposition levels is three.
FIG. 4 is an explanatory diagram showing a precinct.
FIG. 5 is an explanatory diagram showing an example of a procedure for ranking bit planes.
FIG. 6 is a system configuration diagram showing a system including an image processing apparatus according to an embodiment of the present invention.
FIG. 7 is an explanatory diagram showing a schematic configuration of a JPEG2000 code format.
FIG. 8 is an explanatory diagram showing an example of data described in a comment marker of a main header.
FIG. 9 is a block diagram schematically illustrating a hardware configuration of the image processing apparatus.
FIG. 10 is a flowchart schematically showing a flow of an image display process.
FIG. 11 is a chart showing a flow of a program acquisition process.
[Explanation of symbols]
1 Image expansion device
5 Network
10,11 storage media
S program storage device

Claims (8)

An image decompression method for decompressing a compressed code obtained by encoding an image using a decoding program,
When compressing the compression code, managing code related information including program location information indicating the location of at least a decoding program for expanding the compression code with a predetermined marker segment defined in a code format,
Determining whether the compression code to be decompressed is a new image standard that cannot be decompressed by the existing decoding program, based on the code related information managed in the marker segment,
When the compression code is determined to be a new image standard, a decoding program corresponding to the new image standard is obtained according to the program location information included in the code related information managed by the marker segment. Steps to
Decompressing the compression code, which is a new image standard, using a decoding program corresponding to the obtained new image standard,
An image decompression method comprising: 2. The image decompression method according to claim 1, wherein the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker. 3. The image decompression method according to claim 1, wherein the program location information is a URL (Uniform Resource Locator) for specifying a decoding program compliant with a new image standard stored in a program storage device. A compressed code obtained by encoding an image, wherein code-related information including program location information indicating the location of at least a decoding program for expanding the compressed code is managed by a predetermined marker segment defined by a code format. In an image decompression device that decompresses a compression code using a decoding program,
Image standard determining means for determining whether the compressed code to be expanded is a new image standard that cannot be expanded by the existing decoding program based on the code related information managed by the marker segment;
If the compression code is determined to be a new image standard, a decoding program corresponding to the new image standard is sent to the network according to the program location information included in the code related information managed by the marker segment. Program acquisition means for acquiring from a program storage device connected via
Image decompression means for decompressing the compression code, which is a new image standard, using a decoding program corresponding to the obtained new image standard,
An image decompression device comprising: The image decompression device according to claim 4, wherein the code format is a JPEG2000 code format, and the marker segment for managing the code related information is a COM marker. 6. The image decompression device according to claim 4, wherein the program location information is a URL (Uniform Resource Locator) for specifying a decoding program corresponding to a new image standard stored in the program storage device. A compressed code obtained by encoding an image, wherein code-related information including program location information indicating the location of at least a decoding program for expanding the compressed code is managed by a predetermined marker segment defined by a code format. A program to be installed or interpreted and executed on a computer having an image decompression device that decompresses a compression code using a decoding program,
An image standard determination function for determining whether or not the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program based on the code related information managed by the marker segment;
If the compression code is determined to be a new image standard, a decoding program corresponding to the new image standard is sent to the network according to the program location information included in the code related information managed by the marker segment. Program acquisition function to acquire from a program storage device connected via
An image decompression function for decompressing the compression code, which is a new image standard, using a decoding program corresponding to the obtained new image standard,
For causing the computer to execute. A compressed code obtained by encoding an image, wherein code-related information including program location information indicating the location of at least a decoding program for expanding the compressed code is managed by a predetermined marker segment defined by a code format. A storage medium for storing a program that is installed in a computer having an image decompression device that decompresses a compression code using a decoding program, or that is interpreted and executed,
An image standard determination function for determining whether or not the compression code to be expanded is a new image standard that cannot be expanded by the existing decoding program based on the code related information managed by the marker segment;
If the compression code is determined to be a new image standard, a decoding program corresponding to the new image standard is sent to the network according to the program location information included in the code related information managed by the marker segment. Program acquisition function to acquire from a program storage device connected via
An image decompression function for decompressing the compression code, which is a new image standard, using a decoding program corresponding to the obtained new image standard,
A program for causing a computer to execute the above.

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