JP2004040674A - Restoration method for jpeg2000 code data and restoration system for jpeg2000 code data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To progressively display JPEG2000 code data at high speed. <P>SOLUTION: A reconstitution part 106 of a server extracts only a range of a tile requested from a receiving side from the JPEG2000 code data in which only code data corresponding to a resolution requested from the receiving side are recorded on a medium to reconstitute and transmit the JPEG2000 code data by a transmission part 105. A display part 101 of a client improves a resolution level in order from a resolution level of an image displayed at present and requests image data for each resolution level in such a case. A receiving part 102 receives and decodes code data of a sub-band corresponding to the resolution level from the server in response to the request, the decoded code data of the sub-band are saved in a coefficient saving part 104 and while using the decoded code data of the sub-band and code data of a sub-band decoded at a previous resolution level, inverse wavelet transformation is performed to restore the image data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for restoring JPEG2000 code data and a system for restoring JPEG2000 code data, and in particular, when receiving JPEG2000 code data through a line such as the Internet and performing progressive display, an image can be displayed at higher speed than in the past, and a designated image can be displayed. The present invention relates to a JPEG2000 code data restoration method and a JPEG2000 code data restoration system capable of displaying an arbitrary range at high speed.
[0002]
[Prior art]
Generally, JPEG2000 encoded data recorded on a storage medium is transmitted from a server to a client in the order recorded on the medium, and is progressively displayed.
[0003]
In JPEG2000 encoding, a wavelet transform technique is employed. The server divides the image into tiles, converts the coefficient data of the image separated by the multiple wavelet transform into tiles into subbands, and further converts the subbands into bit planes arranged in powers of two, and performs binary coding. Was stored in a storage medium. When the display tile range and its resolution level are specified by the client, the code of the specified resolution level is selected from the code data of the lowest level of the JPEG2000 code data stored in the storage medium for the specified tile. I was taking out the data and sending it.
[0004]
The image data obtained in the process of decoding the JPEG2000 encoded data at the client becomes more detailed in the progressive order as the decoding progresses. The progressive display is performed by displaying the image in the middle of the decoding.
[0005]
That is, the client receives the JPEG2000 code data of the resolution from the server while increasing the resolution level by one step from the lowest level until an image of the resolution level input for the tile range input by the operator is displayed, and decodes the data. And display the image.
[0006]
Since the sub-band LL, which is a low-frequency component coefficient obtained by the inverse wavelet transform at the time of decoding, is a low-resolution image of the component in the original image, the resolution level of the multiple inverse wavelet transform process is switched in the progressive display in JPEG2000. At the timing, it is displayed by using the sub-band LL coefficient decoded so far.
[0007]
It is also possible to display the chrominance component after the detailed display of the luminance component by selecting the progressive order, or to display the images in a raster order from the upper left to the lower right of the image.
[0008]
[Problems to be solved by the invention]
However, the above-described related art has the following problems.
[0009]
The first problem is that the client raises the resolution level one by one from the lowest level until the image of the resolution level input for the tile range input by the operator is displayed from the server. When the server receives a request, the server extracts code data from the beginning of the JPEG2000 code data to the specified resolution every time a reception request is received and transmits the data. In some cases, transmission and decoding of JPEG2000 code data having the resolution level described above overlap with each other, and extra time is required for transmission and decoding of the portion.
[0010]
For example, in the coded data to be transmitted, about one-fourth of the coded data whose resolution level has increased by one level overlaps the coded data of the previous resolution level. In the process of decoding the code data, a portion for processing about 1/4 of the code data overlaps.
[0011]
The second problem is that the server extracts only the point of interest designated by the client from the JPEG2000 code data and transmits it, and the client decodes the image data of the part obtained by decoding only the code data of the point of interest by then. That is, there is no means for combining and displaying a progressive image that is being displayed, and an arbitrary range of the image cannot be displayed at high speed.
[0012]
An object of the present invention is to provide a system capable of displaying an image at a higher speed than that of the related art when progressive display is performed by receiving JPEG2000 code data through a line such as the Internet.
[0013]
It is another object of the present invention to provide a system capable of displaying an arbitrary range specified by a side displaying an image at a high speed.
[0014]
[Means for Solving the Problems]
According to a first aspect of the present invention, JPEG2000 encoded data of an image is stored in a file on a server in advance, and a client retrieves the JPEG2000 encoded data from the file on the server and restores the JPEG2000 encoded data when progressively displaying the JPEG2000 encoded data. The method wherein the server retrieves code data of only subbands of a resolution level specified by the client of the image from the file and transmits the code data to the client, wherein the client performs the resolution level of the image currently displayed. The resolution level is sequentially increased from this time, and at that time, the code data of the sub-band corresponding to the resolution level is received from the server and decoded for each of the resolution levels, and the decoded code data of the sub-band is decoded in advance. In the prepared coefficient storage Image data by performing inverse wavelet transform using the decoded code data of the sub-band and the code data of the sub-band decoded at the resolution level before the decoding in the coefficient storage unit. It is characterized by doing.
[0015]
According to a second aspect of the present invention, in the first aspect, the client first receives and decodes the code data of the sub-band of the low-frequency component coefficient LL having the lowest resolution level from the server and decodes the decoded LL. The image data is restored by performing the inverse wavelet transform of the code data of the sub-band, and the decoded LL sub-band coefficients are stored in a coefficient storage unit prepared in advance, and are increased each time the resolution level is increased from the next time. The code data of the three sub-bands HL, LH, and HH corresponding to the resolution level are received from the server and decoded, and the coefficients stored in the coefficient storage unit and the decoded coefficients HL, LH, HH performs the inverse wavelet transform to restore the image data, and stores the decoded coefficients HL, LH, HH in the coefficient storage unit. And wherein the Rukoto.
[0016]
A third invention of the present application is characterized in that the code data of the subband transmitted from the server to the client according to the first invention is in a JPEG2000 format.
[0017]
A fourth invention of the present application is characterized in that the sub-band of the first invention is the sub-band of an arbitrarily designated portion of the image.
[0018]
According to a fifth aspect of the present invention, in the fourth aspect, the designation of any part of the image is divided into a plurality of tiles in advance, and each tile is assigned a number. It is specified by a number.
[0019]
According to a sixth aspect of the present invention, JPEG2000 encoded data of an image is stored in a file on a server side in advance, and a client retrieves the JPEG2000 encoded data from the file on the server and restores the JPEG2000 encoded data when progressively displaying the JPEG2000 encoded data. In the system, the server including: a reconstructing unit that retrieves code data of only the subband of the resolution level specified by the client of the image from the file; and a transmission unit that transmits the retrieved code data to the client. A display unit for requesting image data corresponding to the resolution level for each of the resolution levels, and the resolution level in response to the request; Of the subband corresponding to Receiving the decoded data from the server, storing the decoded code data of the sub-band in a coefficient storage unit prepared in advance, and decoding the decoded code data of the sub-band and the decoding in the coefficient storage unit. And a receiving unit that performs inverse wavelet transform using the code data of the sub-band decoded at the resolution level before the conversion and restores the image data.
And the client.
[0020]
According to a seventh aspect of the present invention, in the sixth aspect, the receiving section first receives and decodes the code data of the sub-band of the low frequency component coefficient LL having the lowest resolution level from the server and decodes the decoded LL. The image data is restored by performing the inverse wavelet transform of the code data of the sub-band, and the decoded LL sub-band coefficients are stored in a coefficient storage unit prepared in advance, and are increased each time the resolution level increases. The coefficient data of the three sub-bands HL, LH, and HH corresponding to the obtained resolution level are received from the server and decoded, and the coefficients stored in the coefficient storage unit and the decoded coefficients HL and LH , HH to perform the inverse wavelet transform to restore the image data, and store the decoded coefficients HL, LH, HH in the coefficient storage unit. The features.
[0021]
According to an eighth invention of the present application, the code data of the subband transmitted from the reconfiguration unit of the server to the client of the sixth invention is in a JPEG2000 format.
[0022]
A ninth aspect of the present invention is characterized in that the sub-band of the sixth aspect is the sub-band of an arbitrarily designated portion of the image.
[0023]
In a tenth aspect of the present invention, in the ninth aspect, the designation of any part of the image is divided into a plurality of tiles in advance, and each tile is assigned a number. It is specified by a number.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0025]
Referring to FIG. 1, the JPEG2000 communication system of the present invention includes a server and a client.
[0026]
The client includes a display unit 101 for displaying image data, a receiving unit 102 for receiving code data from the server, a decoder 103 for decoding the code data to obtain image data, and a coefficient storage unit 104. I have.
[0027]
The server stores the transmitting unit 105 that transmits the encoded data to the client, the reconstructing unit 106 that extracts the encoded data corresponding to the image range and resolution requested by the client from the JPEG2000 file and reconstructs the encoded data into the JPEG2000 format, and stores the encoded data. And a JPEG2000 file 107.
[0028]
Each of these means operates as follows.
[0029]
The display unit 101 of the client has parameters of a type of display image, a display range, and a resolution, requests image data with the parameters to the receiving unit 102, and displays the received image data as a response.
[0030]
The receiving unit 102 issues a request to the transmitting unit 105 of the server using the communication unit based on the request from the display unit 101, receives code data from the transmitting unit 105 as a response, and then sends the parameter and code to the decoder 103. And pass the data.
[0031]
The decoder 103 decodes the code data received from the receiving unit 102, reads the coefficients from the coefficient storage unit 104 if necessary, performs inverse wavelet transform on the decoded data, and creates image data one step higher in resolution, Hand over to receiving section 102.
[0032]
Further, the receiving unit 102 stores the created coefficient of the image data in the coefficient storage unit 104.
[0033]
The coefficient storage unit 104 is a place where the decoder 103 stores coefficients.
[0034]
The transmitting unit 105 of the server receives the request from the receiving unit 102 through the transmission path, issues a request to the reconstructing unit 106, obtains the reconstructed JPEG2000 code data from the reconstructing unit 106 as a response, and uses the communication means. To pass the code data to the receiving unit 102.
[0035]
Upon receiving a request from the transmitting unit 105, the reconstructing unit 106 cuts out and reconstructs encoded data corresponding to the type, display range, and resolution of the display image specified by the parameter from the JPEG2000 file to obtain JPEG2000 data. Hand over to 105.
[0036]
The JPEG2000 file 107 holds encoded data corresponding to all resolutions of images handled by the system.
[0037]
Next, the operation of the reconfiguration unit 106 of the server according to the present embodiment will be described with reference to the flowchart of FIG.
[0038]
First, in step S201, the reconstructing unit 106 sends the file name File, the number Tn of designated target tiles, the pointer Tp to the area where the tile number is stored, the resolution level Rx, The output destination out of the configured JPEG2000 code data is input as a parameter. Next, in step S202, SOC to SOD (see FIG. 11 described later) are extracted from the file name File, edited, and output to the output destination out. Next, in step S203, a counter I for repeating the process for the number of tiles Tn times is initialized. In step S204, it is determined whether the process has been performed the number of times specified by the number of tiles. Step S205 is a process of obtaining a tile number Tx to be extracted from the area in which the processing tile number is stored. In the next step S206, a packet corresponding to the tile number Tx resolution level Rx is searched and extracted from the designated File, and output to the output destination out. In the next step S207, the counter is updated. After that, the process returns to the determination process S204. In the determination process S204, after the process of the designated final tile is determined, the process proceeds to step S208, and finally the EOC is output to the output destination out, and the process ends.
[0039]
The reconstructed JPEG2000 code data is transmitted to the client by the transmission unit 105.
[0040]
Next, the operation of the display unit 101 of the client according to the present embodiment will be described with reference to the flowchart of FIG.
[0041]
After startup, in step S301, initialization of the display unit, initialization of the reception unit, and the like are performed. Next, in step S302, occurrence of an event is waited. If any event occurs, the process of step S302 ends. In step S303, an event that occurs when a new image display request is made is determined. If this progressive request has been made, a progressive display process is performed in step S304, and the process returns to the event waiting step S302.
[0042]
A step S305 determines an event when a request for displaying only a certain portion in detail is generated. If there is a partial detail display request, partial detail display processing is performed in step S306. Thereafter, since the progressive display process of the entire image is continued, the progressive process is performed in step S307, and the process returns to the event waiting step S302.
[0043]
Next, the operation of the progressive processing in step S304 will be described with reference to the flowchart in FIG.
[0044]
First, in step S401, the resolution level DRx of the entire image currently displayed and the resolution level Rx of the entire image requested to be decoded are input as parameters. Next, a decryption request is issued to the receiving unit 102 in step S402. At this time, the file name to be displayed, the request for all tiles, and the resolution level Rx of the requested image as a whole are given as parameters. After that, in order to wait for the completion of the decoding, the process waits for the occurrence of an event in step S403. If any event occurs, the process of step S403 ends. In step S404, an event that occurs when the resolution level Rx of the entire designated image has already been decoded is determined. If the decoding has already been performed, the process of step S405 for determining an event that occurs when the reception and decoding of the code data of the designated resolution level is completed is not performed. Step S406 is a process performed when the operation of the receiving unit is completed, and changes the resolution level DRx of the entire currently displayed image and the resolution level Rx of the entire image requested to be decoded to higher levels. Thereafter, a decryption request is issued to the receiving unit 102 in step S407. At this time, the resolution level Rx of the entire image requested to be decoded is one step higher than the previous time.
[0045]
Next, in step S408, a process of displaying, on a display or the like, an image of the resolution level DRx of the entire image for which decoding has been completed and occurrence of an event has been confirmed in step S408. If necessary, the decoded image is enlarged to have the same size as the current image. Thereafter, the process proceeds to step S403 in order to wait for a response event to the decryption request to the receiving unit 102 issued in step S407. If it is determined in step S405 that the event is not the reception decoding completion event, it means that another event has occurred, and the progressive process ends. At this time, if the receiving unit is operating, the operation is stopped. Therefore, a decoding stop request is issued in step S409 before the end of the progressive processing. It is designed so that a response event to this request does not occur.
[0046]
Next, the operation of the partial detail display process in step S306 will be described with reference to the flowchart in FIG.
[0047]
The partial detail display processing in step S306 performs an operation similar to the operation of the progressive processing in step S304. The difference is that the parameters of the decoding request to the receiving unit performed in step S502 and step S507 are tiles in the specified range, and in step S508 the decoded partial image of the display resolution level PDRx is The point is that the image is synthesized with a progressive image showing the entire image.
[0048]
Next, the operation of the receiving unit 102 will be described with reference to the flowchart in FIG.
[0049]
First, after startup, in step S601, initialization of the reception unit 102 and initialization of the coefficient storage unit 104 are performed. Next, in step S602, occurrence of an event is waited. If any event occurs, the process of step S602 ends. A step S603 discriminates a request event for receiving and decoding an image from the display unit 101. If there is this request, a reception request process is performed in step S604. At this time, the requested tile number, resolution level, and the like are given as parameters. After the reception request processing, the process returns to the event waiting step S602 to wait for the reception completion event.
[0050]
A step S605 determines an event when there is a response to the reception request processing in the step S604. If there is a response event of the reception request process, a process of issuing a request to decode the coded data received in step S606 is performed, and the process returns to the event waiting step S602.
[0051]
A step S607 determines an event when a response to the decryption request processing request of the step S606 is received. If there is a response event of the decryption request processing request, a coefficient update process for storing the decrypted coefficient is performed in step S608, and the process returns to the event waiting step S302.
[0052]
A step S609 discriminates an event when there is a decoding stop request from the display unit 101. If there is a decoding stop request, a reception stop request is issued in step S610, and the process returns to the event waiting step S602.
[0053]
In step S611, an event when reception has actually stopped in response to the reception stop request in step 610 is determined. After the reception is stopped, the process returns to the event waiting step S602.
[0054]
If it is determined in step S611 that the event is not the reception stop event, it is an end event, and the receiving unit ends.
[0055]
Next, the operation of the receiving unit 102 in step S604 will be described with reference to the flowchart in FIG.
[0056]
First, in step S701, the file name File of the image to be displayed, the number Tn of tiles requested to be received, the pointer rTp storing the requested tile number, the pointer Tp storing the tile number requested from the server, and the request are requested. The user inputs a resolution level Rx and a resolution level storage area of the coefficient storage unit 104 used to determine whether or not the tile number is a request for a server.
[0057]
Next, in step S702, it is determined whether the coefficient data stored in the coefficient storage unit is the same as the requested file, and if different, the reference flag F is set to 0 in step S703. Even if the requested file is the same as the requested file, if the request is for an image of the lowest resolution level of the entire image, the reference flag F is set to 0 in step S703. Otherwise, the reference flag F is set to 1.
[0058]
Next, in step S704, a counter I for processing the number of requested tiles and a counter n for managing the number of tiles for which a reception request is issued are initialized.
Next, in step S705, it is determined whether the requested number of tiles has been processed. If the number of requested tiles has not been processed, one of the requested tile numbers is stored in the tile number Tx to be processed in step S706. In step S707, it is determined whether the reference flag F is 1 and the resolution level sRx [Tx] of the designated tile number stored in the coefficient storage unit is higher than the requested resolution level. This is to avoid receiving and decoding the tile of the specific tile when only the specific tile is decoded and displayed to the highest resolution in the partial detail display step S306. If it is determined in step S707 that the tile number Tx is the tile to be received, the tile number Tx is stored in the pointer Tp for storing the tile number to be requested from the server in step S708, and the number of tiles for which the reception request is issued Is counted up.
[0059]
Next, the counter I for processing the requested number of tiles is counted up in step S709, and step S705 is performed again.
[0060]
If it is determined in step S705 that the number of times of the requested number of tiles has been processed, the process proceeds to step S710, and the parameters of the storage pointer Tp of the requested file name File, the resolution level Rx, and the tile number requested of the server are used. A reception request is issued to the server, and the process ends.
[0061]
Next, the operation of step S606 of the receiving unit 102 will be described with reference to the flowchart of FIG.
[0062]
First, in step S801, the number Tn of tiles to be decoded, the pointer Tp storing the tile number, the resolution level Rx to be decoded, the pointer in storing the received code data, and the decoded image data Is input, such as a pointer out to an area for storing.
[0063]
Next, in step S802, a coefficient storage unit address storage area Kp for storing an address to coefficient data for each tile number stored in the coefficient storage unit 104 is prepared.
[0064]
Next, in step S803, a counter I for processing the number of received tiles is initialized.
[0065]
Next, in step S804, it is determined whether the number of received tiles has been processed. If the number of tiles has not been processed, one of the tile numbers to be decoded is extracted to Tx in step S805, and the address of the coefficient to be referred to when decoding the tile number Tx in step S806 is set to Kp [Tx]. Store. Next, the counter I is counted up in step S807, and step S804 is performed again.
[0066]
When the number of tiles received in step S804 has been processed, all of the coefficients of the coefficient storage unit 104 corresponding to each of the tiles of the received code data have been collected, so that the code data in received in step S808 is stored. A decoding request is issued to the decoder 103 together with the parameters such as the coefficient Kp, which is present, and the process ends.
[0067]
Next, the operation of the receiving unit 102 in step S608 will be described with reference to the flowchart in FIG.
[0068]
First, in step S901, the decrypted file name File, the number of decrypted tiles Tn, the pointer Tp storing the tile number, the decrypted resolution level Rx, and the tiles obtained by the decryption by the decryptor , A coefficient storage area sKp for each tile number of the coefficient storage unit 104, a resolution level storage area sRx for each tile number of the coefficient storage unit 104, and the like.
[0069]
Next, in step S902, the decrypted file name File is compared with the file name Kfile of the coefficient storage unit. If they do not match, the data stored in the coefficient storage unit 104 is for a new file, so the coefficient storage unit 104 is initialized in step S903. Also, when all tiles having the lowest linear density have been decoded in step S902, the coefficient storage unit 104 is initialized.
[0070]
Next, in step S904, a counter I for processing the number of times of decoding of the number of tiles is initialized.
[0071]
Next, in step S905, it is determined whether the number of times of decoding the number of tiles has been processed. If the number of tiles has not been processed, one of the tile numbers decoded in step S906 is taken out as Tx, and in step S907, the decoded resolution level Rx of the tile number Tx and the coefficient iKp [Tx] are stored in the coefficient storage unit. Store. Next, the counter I is counted up in step S908, and step S905 is performed again.
[0072]
If it is determined in step S905 that the number of times of decoding the number of tiles has been processed, all the coefficients for the decoded tile have been saved, and the process ends.
[0073]
Next, with reference to FIGS. 10, 11, 12, and 13, a method of reconstructing a JPEG2000 code according to the present embodiment and coefficients in a decoding process will be described in detail.
[0074]
FIG. 10 shows coefficients after wavelet multi-resolution conversion in the case of resolution decomposition level 3 in one tile of one component, and these coefficients are encoded by predictive arithmetic codes. The order of encoding the coefficients is (1) to (10). When the decoded data of the coefficient (1) is decoded and the inverse wavelet transform is performed, an image with the lowest resolution is obtained. Assuming that the resolution of this image is r, image data having a resolution of 2r can be obtained by decoding the coefficient decoded data of (1), (2), (3) and (4) and performing inverse wavelet transform. Similarly, image data with a resolution of 4r can be obtained from coefficient code data of (1) to (7). Similarly, an image having a resolution of 8r (highest image quality) can be obtained from (1) to (10).
[0075]
FIG. 11 shows an example of the JPEG2000 format in the case where the resolution decomposition level is 3 and the number of tiles is 1. The coefficient code data (1) to (10) in FIG. 11 correspond to the coefficient code data (1) to (10) in FIG. In this JPEG2000 format, when extracting code data for each resolution, an SOP marker is detected and code data is extracted. In JPEG2000 code data, an EOP marker may be further used.
[0076]
FIG. 12 shows an example of the JPEG2000 code data reconfigured by the server reconfiguration unit 106 of the JPEG2000 communication system of FIG.
[0077]
When the number of tiles is 1 at resolution resolution level 4, the image data is divided and reconstructed into four JPEG2000 coded data from A (resolution r) to D (resolution 8r), and A, B, C, and D are decoded according to the client's request. Sent in order.
[0078]
FIG. 13 shows the relationship between the code data input when the client performs the progressive display and the held coefficient LL.
[0079]
First, the JPEG2000 coded data A of FIG. 13 is input to the decoder. The decoder performs arithmetic code decoding on the code data A and performs inverse wavelet transform to generate a coefficient LL (NL = 0).
[0080]
When one pixel is a single color, the coefficient LL becomes display image data. However, when an image represented by RGB 24 bits is subjected to color space conversion and encoded, the coefficient LL after the inverse wavelet transform has one luminance component. Since it is composed of two color difference components, these components are subjected to color space conversion to obtain RGB image data for display.
[0081]
Next, when an image having a resolution of 2r is required, the code data B and the previously output coefficient LL (NL = 0) are input, and the data and coefficient obtained by performing arithmetic code decoding on the code data B are input. When the inverse wavelet transform is performed using LL (NL = 0), a coefficient LL (NL = 1) and an image having a resolution of 2r are obtained.
[0082]
Similarly, when obtaining an image with a resolution of 4r and an image with a resolution of 8r, it can be obtained by decoding received code data and performing inverse wavelet transform together with coefficients of the previous resolution. The highest resolution coefficient data is discarded.
[0083]
Next, a method of extracting and reconstructing a part of the JPEG2000 encoded data in the present system will be described with reference to FIGS.
[0084]
FIG. 14 shows the relationship between an image and a tile in the case where tiles each having 256 pixels in length and width and 256 lines in the image are set. In FIG. 14, since the image size is 1024 pixels and 1024 lines, the number of tiles is 16. In JPEG2000 encoding, encoding is performed in tile units, and the present system uses this to cut out encoded data in tile units. If the image size and the tile size are the same size, the number of tiles is 1, so that code data cannot be cut out. Therefore, in this system, fixed-size tiles are set as shown in the example of FIG.
[0085]
In FIG. 14, when the client request range shown in the figure is designated as the range to be displayed in detail, the tile 11, tile 12, tile 15 and tile 16 are included in the designated range, so the server cuts out the code data of the designated tile. Reconstruct the JPEG2000 code and send it to the client. After the client decodes the received code data and obtains image data of tiles 11, 12, 15, and 16, only necessary image portions are masked and displayed.
[0086]
FIG. 15 is an example of a JPEG2000 encoding format of a single component image having 16 tiles.
[0087]
FIG. 16 is an example of the JPEG2000 encoding format in which the tiles of tile 11, tile 12, tile 15, and tile 16 requested by the client are cut out from the JPEG2000 encoding format of FIG. 15 and reconstructed into the JPEG2000 encoding format. Bit Stream in FIGS. 15 and 16 is data obtained by encoding a sub-band in a tile, and corresponds to code data from the first SOP to before the EOC in FIG. When transmitting to a client, as shown in FIG. 12, it is reconstructed for each resolution and output.
[0088]
When the image is composed of a total of three components, that is, a luminance (Y) space, a color difference 1 (Cb) space, and a color difference 2 (Cr) space, the Bit Stream has the structure shown in FIG.
[0089]
The JPEG2000 communication system has a function of reconstructing the JPEG2000 encoding format in units of resolution described above and a function of reconstructing the JPEG2000 encoding format by cutting out a tile including a range designated by the client.
[0090]
In this embodiment, instead of processing the code data of each resolution of the progressive display from the beginning of the JPEG2000 code data, the JPEG2000 code obtained by retrieving only the coefficients generated in the processing up to that point and the code data of the resolution is reconstructed. Since the high-resolution image data is restored using the data, the data transfer amount and the decoding processing amount can be reduced to about ／ of the conventional processing.
[0091]
Further, in the present embodiment, since only the code data corresponding to an arbitrary rectangular portion is extracted from the original JPEG2000 code data, the JPEG2000 code data is reconstructed, and transmission and decoding are performed. , Only an arbitrary portion can be displayed at high speed.
[0092]
FIG. 18 shows an example of an image display in a process where, when a mouse is designated during progressive display of JPEG2000 code data, a portion is sequentially displayed in detail outward from the designated portion. Since the JPEG2000 communication system of the present invention is capable of cutting out JPEG2000 encoded data in tile units and performing progressive display, the outer images are sequentially displayed in tile units from the tile indicated by the mouse in order of progressive display or highest image quality. It works to display.
[0093]
The present embodiment is particularly effective for JPEG2000 code data having a large image size. First, progressive display of the entire image is performed, and when a part to be displayed at a high resolution is specified when an image has been identified to some extent, that part is centered. There is an advantage that the display of a high-resolution image is realized.
[0094]
【The invention's effect】
As described above, according to the present invention, when receiving and displaying JPEG2000 code data through a communication line, the coefficient of a low frequency component at each stage of increasing the resolution level of an image to be displayed is stored. Since JPEG2000 code data that does not include code data corresponding to the stored coefficients is received from, the amount of communication data and the amount of decoding processing are reduced, and there is an effect that progressive display can be performed faster than in the related art.
[0095]
In addition, since it has means for extracting code data of tiles within a specified range from JPEG2000 code data, reconstructing the data in the JPEG2000 format, transferring the data, and decoding the data, an arbitrary range of the image can be displayed quickly. There is an effect that can be done.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a JPEG2000 communication system of the present invention.
FIG. 2 is a flowchart showing the operation of the server reconfiguration unit 106 of the present invention.
FIG. 3 is a flowchart showing an operation of the display unit 101 of the client according to the present invention.
FIG. 4 is a flowchart illustrating an operation of a progressive process according to the present invention.
FIG. 5 is a flowchart illustrating an operation of a partial detail display process according to the present invention.
FIG. 6 is a flowchart illustrating an operation of a receiving unit according to the present invention.
FIG. 7 is a flowchart illustrating an operation of a reception request process of a reception unit according to the present invention.
FIG. 8 is a flowchart illustrating the operation of a decryption request processing request of the receiving unit according to the present invention.
FIG. 9 is a flowchart illustrating an operation of a coefficient update process of the receiving unit according to the present invention.
FIG. 10 is a diagram illustrating coefficients after wavelet multi-resolution conversion in a case where the resolution decomposition level is 3 in one tile of one component.
FIG. 11 is a diagram illustrating an example of a JPEG2000 format in the case where the number of tiles is 1 at resolution resolution level 3;
FIG. 12 is a diagram illustrating an example of JPEG2000 encoded data reconfigured by a server reconfiguration unit of the JPEG2000 communication system.
FIG. 13 is a diagram illustrating a relationship between code data input when a client performs progressive display and a held coefficient LL.
FIG. 14 is a diagram showing an example of a relationship between an image of JPEG2000 code data and a tile and a range specified by a client of the JPEG2000 communication system of the present invention.
FIG. 15 is a diagram illustrating a JPEG2000 format in tile units of the image shown in FIG. 14;
16 is a diagram illustrating the JPEG2000 format when the range illustrated in FIG. 14 is extracted from the image in the JPEG2000 format in units of tiles illustrated in FIG. 15 and reconstructed into the JPEG2000 format.
17 shows a JPEG2000 format when the range shown in FIG. 14 is extracted from the JPEG2000 format image in tile units shown in FIG. 15 and reconstructed into the JPEG2000 format when FIG. FIG.
FIG. 18 is a diagram illustrating an example of the present invention.
[Explanation of symbols]
101 Display
102 Receiver
103 Decoder
104 Coefficient storage unit
105 transmission unit
106 Reconstruction unit
107 JPEG2000 file

Claims (10)

In a method of restoring JPEG2000 code data of an image in a case where JPEG2000 code data of an image is stored in a file on a server side in advance and a client takes out the JPEG2000 code data from the file of the server and progressively displays the JPEG2000 code data, the server The code data of only the sub-band of the resolution level designated by the client is extracted from the file and transmitted to the client, and the client sequentially increases the resolution level from the resolution level of the currently displayed image. At that time, for each of the resolution levels, the code data of the sub-band corresponding to the resolution level is received from the server and decoded, and the decoded code data of the sub-band is stored in a coefficient storage unit prepared in advance. With the return Image data is restored by performing inverse wavelet transform using the converted subband code data and the subband code data decoded at the resolution level before the decoding in the coefficient storage unit. JPEG2000 code data restoration method. The client first receives and decodes the code data of the sub-band of the low frequency component coefficient LL having the lowest resolution level from the server, and performs inverse wavelet transform of the decoded code data of the sub-band of LL to obtain an image. The data is restored and the decoded coefficients of the LL subband are stored in a prepared coefficient storage unit, and the coefficients HL, LH, HH corresponding to the increased resolution levels are increased each time the resolution levels are increased. The code data of the three sub-bands is received from the server, decoded, and the wavelet inverse transform is performed on the coefficients stored in the coefficient storage unit and the decoded coefficients HL, LH, HH to obtain the image data. And restoring the decoded coefficients HL, LH, and HH in the coefficient storage unit. How to restore PEG2000 code data. 2. The method according to claim 1, wherein the code data of the subband transmitted from the server to the client is in a JPEG2000 format. 2. The method according to claim 1, wherein the sub-band is the sub-band of an arbitrarily designated portion of the image. The designation of an arbitrary portion of the image is divided into a plurality of tiles in advance, and each tile is designated by a number of the tile in the image in which a number is assigned. JPEG2000 code data restoration method. In a file on the server side, JPEG2000 encoded data of an image is stored in advance, and the client retrieves the JPEG2000 encoded data from the file of the server and displays the progressively displayed JPEG2000 encoded data in the JPEG2000 encoded data restoration system. A server including a reconstructing unit for extracting code data of only the sub-band of the specified resolution level from the file and a transmission unit for transmitting the extracted code data to a client; and A display unit for requesting image data corresponding to the resolution level for each of the resolution levels, and a code for the subband corresponding to the resolution level in response to the request. Data The decoded code data of the sub-band received and decoded from the sub-band is stored in a previously prepared coefficient storage unit, and the decoded code data of the sub-band and the resolution before the decoding in the coefficient storage unit are stored. A decoding unit for performing a wavelet inverse transform using the code data of the sub-band decoded at the level and restoring the image data, and a client including a JPEG2000 code data restoration system. . The receiving unit first receives the code data of the sub-band of the low frequency component coefficient LL having the lowest resolution level from the server, decodes the data, and performs the inverse wavelet transform of the decoded code data of the sub-band of LL. The image data is restored and the decoded coefficients of the LL subband are stored in a previously prepared coefficient storage unit, and the coefficients HL, LH, The code data of the three subbands of HH is received from the server and decoded, and the wavelet inverse transform is performed on the coefficients stored in the coefficient storage unit and the decoded coefficients HL, LH, and HH to perform image processing on the image. 7. The JPE according to claim 6, wherein data is restored and the decoded coefficients HL, LH, HH are stored in the coefficient storage unit. Recovery system of the 2000 code data. 7. The JPEG2000 code data restoration system according to claim 6, wherein the code data of the subband sent from the reconfiguration unit of the server to the client is in a JPEG2000 format. 7. The system according to claim 6, wherein the sub-band is the sub-band of an arbitrarily designated portion of the image. 10. The specification of any part of the image is divided into a plurality of tiles in advance, and each of the tiles is specified by a number of the tile in the image in which a number is assigned. JPEG2000 code data restoration system.

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