JP2013105204A - Image display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which can improve efficiency of image transmission even when a speed of wireless communication is low (for example when a mobile communication network is used) in an image display system which transmits an image stored in a server side device to a mobile terminal through wireless communication and displays it in a screen of the mobile terminal.SOLUTION: A server device 1 stores a plurality of tile images (divided images) prepared by tiling (dividing into a grid shape) a display object image of a mobile terminal 2. The mobile terminal 2 requests the server device 1 for the plurality of tile images which are required when displaying a part or the entirety of the object image. In response to the request from the mobile terminal 2, the server device 1 transmits in parallel the plurality of tile images corresponding to the request. The mobile terminal 2 receives in parallel the plurality of tile images transmitted from the server device 1 and performs screen display by using the plurality of tile images which are received.

Description

  The present invention relates to an image display system including a portable terminal that can communicate with a server device via a wireless communication network.

  In recent years, an image display system has been realized in which an image held on the server device side is wirelessly transmitted to a mobile terminal (for example, a mobile phone such as a smartphone) and displayed on the screen of the mobile terminal. According to such an image display system, an environment in which an image can be freely viewed on the screen of the mobile terminal can be provided to the user within a range where wireless communication is possible (range of wireless communication). .

  Here, in the mobile terminal, a memory mounted on the mobile terminal is small in size, so that a memory capacity that can be used by an application operating on the mobile terminal is relatively small. In addition, Android (registered trademark of Google Incorporated), which is an example of a platform for operating various applications on a mobile terminal, limits the amount of heap memory that can be used by one application to a specified value (for example, 16 MB). ing. Under such circumstances, it is difficult to use a large image such as a map or a drawing used for lifeline maintenance or seismic maintenance of structures.

  In addition, the time required for transmitting an image from the server device to the portable terminal increases in proportion to the data capacity of the image to be transmitted. In particular, when an image is transmitted using a low communication speed such as a mobile communication network, the larger the image, the more time required for image transmission increases. It can be stressful. Further, even when an image is transmitted using a high communication speed such as WiFi (Wireless Fidelity), a sufficient speed may not be obtained depending on the congestion state of the communication line.

JP 2008-099320 A JP 2010-033611 A

  Here, for example, in Patent Documents 1 and 2, in order to reduce the network traffic, it is possible to tile an image view so that calculation and transmission of view data can be performed in an incremental manner. Caching on the client, caching view tiles on the server, etc. to reduce view tile complexity and to increase the responsiveness of the image view server.

By using such a tiling technique, it is possible to construct an environment in which a large image such as a map or a drawing can be viewed on a portable terminal that has a limited memory capacity.
However, when downloading an image by wireless communication, particularly when using a device that has a communication speed that is not sufficiently high, such as a mobile communication network, the above-described tiling technique is not sufficient. Improvement is required.

  The present invention has been made in view of the above-described conventional circumstances, and relates to an image display system that wirelessly transmits an image held on a server device side to a mobile terminal and displays the image on the screen of the mobile terminal. An object of the present invention is to propose a technique capable of improving the efficiency of image transmission even when the speed of wireless communication is low.

  The present invention is realized as an image display system including a portable terminal capable of communicating with a server device via a wireless communication network, an image display method implemented by the image display system, and a server constituting the image display system It can implement | achieve as an apparatus, a portable terminal, and those programs.

In the image display system according to the present invention, the server device stores a plurality of divided images generated by dividing a target image, and a divided image corresponding to the request in response to a request from the mobile terminal. Transmitting means for transmitting to the portable terminal.
In the image display system according to the present invention, the mobile terminal displays a part or the whole of the target image on the screen of the mobile terminal using a plurality of divided images, and the display by the display means. Receiving means for requesting the server device for a plurality of divided images to be used and receiving in parallel the plurality of divided images transmitted from the server device in response to the request.

That is, the server device stores a plurality of divided images generated by dividing an image to be displayed by the mobile terminal, and the mobile terminal displays a part or all of the target image on the screen of the mobile terminal. In response to a request from the portable terminal, the server device transmits a plurality of divided images corresponding to the request to the portable terminal, and the portable terminal , By receiving a plurality of divided images transmitted from the server device and performing screen display using the received plurality of divided images, the mobile terminal does not have the entire image but a part of the divided image The solution to the limitation that only a limited memory capacity can be used by handling images.
Further, the server device transmits a plurality of divided images in parallel, and the mobile terminal receives the plurality of divided images transmitted from the server device in parallel (for example, requesting one divided image at a time). Restriction that only a limited communication speed can be obtained by making it possible to effectively use the processing performance of the mobile terminal and the communication performance of the wireless communication network. To solve the problem.
As a result, the efficiency of image transmission can be improved even when the speed of wireless communication is low (for example, when a mobile communication network is used or when a communication line is tight).

Here, the receiving unit of the mobile terminal requests the server device for a plurality of divided images adjacent to the divided image displayed on the screen based on a user operation to slide the screen display, and responds to the request. A plurality of divided images transmitted from the server device may be received in parallel.
Thereby, it is possible to efficiently receive a plurality of divided images newly included in the display range by the slide of display.

In addition, the receiving unit of the mobile terminal requests the server device for a plurality of divided images adjacent to the divided images displayed on the screen based on a user operation for reducing the display of the screen, and the server responds to the request. A plurality of divided images transmitted from the apparatus may be received in parallel.
Accordingly, it is possible to efficiently receive a plurality of divided images newly included in the display range due to display reduction.

In addition, the storage unit of the server device stores a plurality of divided images generated by dividing the images for each of a plurality of different scale images obtained by the reduction process on the target image, and the reception unit of the mobile terminal However, based on a user operation for reducing the display of the screen, the server device is requested to request a plurality of divided images having a scale smaller than the divided image displayed on the screen, and the plurality of images transmitted from the server device in response to the request. The divided images may be received in parallel.
Thereby, it is possible to efficiently receive a plurality of divided images having a scale suitable for display after reduction. Further, it is possible to prevent the number of divided images used for display reduction from becoming large.

In addition, the storage unit of the server device stores a plurality of divided images generated by dividing the images for each of a plurality of different scale images obtained by the reduction process on the target image, and the reception unit of the mobile terminal However, based on a user operation for enlarging the display on the screen, the server device is requested to request a plurality of divided images having a scale larger than that of the divided images displayed on the screen, and the plurality of images transmitted from the server device in response to the request. The divided images may be received in parallel.
Accordingly, it is possible to efficiently receive a plurality of divided images having a scale suitable for display after enlargement. In addition, it is possible to obtain a better image quality than when the display is enlarged only by image processing.

The server device may further include a dividing unit that divides the target image to generate a plurality of divided images, and the storage unit of the server device may store the plurality of divided images generated by the dividing unit. .
Thereby, a divided image can be generated as necessary, and the storage capacity of the server device can be reduced.

  According to the present invention, it is possible to effectively increase the efficiency of image transmission even when the speed of wireless communication is low (for example, when using a mobile communication network or when a communication line is tight). As a result, the operability (handling) of image browsing in the terminal device can be improved.

1 is a diagram showing an outline of an image display system according to an embodiment of the present invention. It is a figure which shows the example of the functional block of a server apparatus and a portable terminal. It is a figure which shows the example of the processing flow of the tiling process in a server apparatus. It is a figure which shows the example of the processing flow of the tile download process and drawing process in a portable terminal. It is a figure which shows the example which verified the size of the tile image from a viewpoint of communication, efficiency, and usability. It is a figure which shows the example which verified the number of download threads.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an image display system according to an embodiment of the present invention.
The image display system of this example is configured so that the server device 1 and the portable terminal 2 can communicate with each other via the mobile communication network 3, and the server device 1 tiles an image to be displayed by the portable terminal 2 ( Divided into tiles), downloaded (transmitted) from the server device 1 to the portable terminal 2 in tile units, and drawn (displayed) on the screen of the portable terminal 2 to display to the user of the portable terminal 2 It provides a viewing environment for a part or the whole of the target image.

In FIG. 2, the example of the functional block of the server apparatus 1 and the portable terminal 2 is shown.
The server device 1 of this example includes a communication interface unit 14 used for communication with other devices, an image database 13 that stores and manages data of a plurality of images, and a plurality of tile images ( A tiling unit 12 that generates (divided image) data, a tile data holding unit 15 that stores tile image data, and a request processing unit 11 that performs processing in response to a request from the portable terminal 2.

  In addition, the portable terminal 2 of this example includes a communication interface unit 21 used for communication with other devices, an operation input unit 22 that receives various operation inputs from a user, and a screen 23 that serves as an image display destination (display surface). , A download processing unit 24 that downloads (receives) tile image data from the server device 1, a tile data holding unit 25 that stores downloaded tile image data, and a part or all of a display target image that includes a plurality of tile images. A tile drawing unit 26 for drawing (displaying) on the screen 23 based on the data is provided.

In this example, a mobile phone such as a smartphone capable of data communication using a third generation (so-called “3G”) mobile communication network is used as the mobile terminal 2, and Android is used as a platform for operating each application. Note that these are merely examples, and the standard and platform of the wireless communication network to be used are arbitrary. For example, as the mobile terminal 2, a PDA (Personal Digital Assistant) or a tablet PC that can perform data communication using WiFi is used. A portable small terminal may be used.
Further, in the portable terminal 2 of this example, a touch panel that functions as the screen 23 and the operation input unit 22 is provided and a touch operation on the screen 23 is detected by the operation input unit 22. May be configured by different hardware.

Next, specific processing contents by the functional units of the server device 1 and the mobile terminal 2 will be described along the flow of the operation of the image display system.
First, as pre-processing, data of a plurality of images that can be displayed by the mobile terminal 2 are registered in the image database 13 of the server device 1 from, for example, another terminal connected via the Internet network. In this example, the image itself is not stored in the image database 13, but is stored in a compressed (encoded) state by a predetermined compression method (for example, UCV (Ultra Compressor Vector)), and is expanded when used ( The disk capacity of the image database 13 is reduced by adopting a configuration in which the image is restored by decoding. Note that the image compression may be performed before the transmission of the image by the transmission source terminal side, or may be performed by the server device 1 after the reception of the image.

  Here, for example, a plurality of images stored in the image database 13 of the server device 1 are displayed in a list format on the screen 23 of the mobile terminal 2, and an operation input for designating one of the images as a display target is performed. Suppose that it was performed by the user (user). This operation input is detected by the operation input unit 22 and triggered by this operation, tiling and downloading of an image designated as a display target is started.

  First, in the mobile terminal 2, the download processing unit 24 transmits a tiling request for requesting tiling of an image designated as a display target to the server device 1 through the communication interface unit 21. In the tiling request of this example, an image to be tiled is designated by an image identifier (file ID in this example) that is identification information of an image designated as a display target.

  When the server apparatus 1 receives the tiling request transmitted from the mobile terminal 2 by the communication interface unit 14, the request processing unit 11 performs tiling of the image tiling corresponding to the image identifier specified by the tiling request. The unit 12 is instructed.

  The tiling unit 12 reads out the compressed data of the image corresponding to the instructed image identifier from the image database 13 and decompresses it, and restores the image before compression. Further, when the image format of the restored image is different from the image format that can be used in the mobile terminal 2, the image format is also converted. In this example, an image in JPEG (Joint Photographic Experts Group) format is basically used, but in the case of an image with a small number of colors, an image in PNG (Portable Network Graphics) format may be used. Thereafter, tiling processing is performed using the image of the restoration (and conversion) result as an original image.

Details of the tiling process will be described with reference to an example of a process flow shown in FIG.
Here, in this example, not only a tile image obtained by dividing the original image but also a tile image obtained by dividing a reduced image (or a further reduced image) obtained by reducing the original image is generated. The degree is distinguished by the layer number. In the following, the original image (original image) is layer 1, the reduced image with each side length halved is layer 2, the reduced image with each side length ¼ is layer 4,.・. In this example, a tile image having a size smaller than the size of the screen (display area) of the mobile terminal is used. For example, the length of one side of the tile image is set to 256 pixels.

  In the tiling process, first, a layer that is a variable representing a layer number and a tile size that is a variable representing a tile size (length of one side) are set (step S21). In this example, as an initial value, 1 is set to the variable layer and 256 is set to the variable tilesize.

Next, a reduction process (step S12) and a cut-out process (step S13) are performed.
In the reduction process (step S12), the original image is reduced to (1 / layer), and the reduced image is set to img. In the cutout process (step S13), a plurality of tile images are generated by sequentially cutting out tilesize squares from the upper left to the lower right of img, and the data of each tile image is stored in the tile data holding unit 15. Note that the end of img (right side and lower side) cannot be cut out of a square and may be a rectangular tile image.
Here, in the first reduction process and cut-out process, since layer = 1, img is the original image itself (original size), and the original image is divided into tile images in units of 256 pixels.

Next, it is determined whether or not the height or width of img is equal to or smaller than a reference value (1024 pixels in this example) in order to determine whether to perform further reduction processing and cutout processing (step S14).
As a result, if it is determined that the height or width of img is not equal to or less than the reference value, (layer * 2) is set to layer (step S15), the process returns to step S12, and the second reduction process and cutout are performed. Process.
Since layer = 2 in the second reduction process and cut-out process, img is a reduced image obtained by halving the original image, and this 1/2 reduced image is divided into tile images in units of 256 pixels. become.
The above processing (steps S12 to S15) is repeated until it is determined in step S14 that the height or width of img is equal to or less than the reference value.

  As a result, a plurality of tile images of different scales are generated from a plurality of images of different scales (original image and its reduced image). In this way, the original image (original size image) is sequentially reduced to generate a plurality of reduced images having different scales, and each is divided to generate a tile image. Good image quality can be obtained even if the tile image is used. Note that the tile images of each scale are basically the same size (except for the edge of the divided original image), and the difference in the scale of the tile image corresponds to the difference in the size of the corresponding area on the original image.

  In this example, the data of each tile image includes an image identifier (file ID in this example) that is identification information of the original image, a layer number that is identification information of the layer, an original image (original image or its image). X position indicating the arrangement of the tile in the X-axis direction (horizontal direction) in the reduced image), and Y position indicating the arrangement of the tile in the Y-axis direction (vertical direction) in the original image (original image or its reduced image) , Are all stored in the same folder in the tile data holding unit 15. Note that this file system is an example, and tile image data may be managed by another file system. For example, a folder for each original image (that is, a folder for each file ID) may be prepared.

  In this example, 256 is used as the number of pixels (tilesize) that defines the size of the tile image, and 1024 pixels are used as a reference value for determining whether or not to reduce the image. Is merely an example, and for example, an appropriate value may be determined in consideration of various factors such as the screen size and memory capacity of the mobile terminal 2 or communication, efficiency, and feeling of use described later.

  When the tiling processing (reduction processing and cut-out processing) by the tiling unit 12 ends, the request processing unit 11 displays the result of the tiling processing (for example, the maximum value of the X position and Y position for each layer number) as a communication interface. Notification to the mobile terminal 2 through the unit 14.

  When the mobile terminal 2 receives the result of the tiling process notified from the server device 1 by the communication interface unit 21, the download processing unit 24 selects a necessary tile image based on the result of the tiling process. Download processing is performed, and the tile drawing unit 25 performs drawing processing of the downloaded tile image.

  Details of the tile image download processing and drawing processing will be described with reference to the example of the processing flow shown in FIG. The download processing unit 24 of this example performs the tile image download process by operating the main thread T1 and the download thread T2. Further, the tile drawing unit 25 of this example performs a tile image drawing process by operating the display thread T3.

The main thread T1 will be described with reference to FIG.
In the main thread T1, first, a center that is a variable indicating the position of an image to be displayed in the center of the screen, a view size that is a variable that indicates a screen size, a layer that is a variable that indicates a layer number, and a tile size (one side) The setting of tilesize, which is a variable representing (length), is performed (step S21).

Here, a unique value (screen size) for each model of the mobile terminal 2 is fixedly set in the variable viewsize, and the variable tilesize has the same value as the variable tilesize used in the server device 1 (in this example, 256) is fixedly set. That is, the variable center and the variable layer are adjusted as necessary.
For example, at the time of initial display, a tile image having the smallest scale (the largest reduction ratio) (that is, the tile image having the largest layer number) is used so that the entire image can be grasped. A variable center and a variable layer are set so as to be located at the center of the screen. Further, for example, when a user operation to slide (shift) the display range is performed, the variable center is adjusted according to the slide amount. For example, when a user operation for enlarging or reducing the display is performed, the variable layer is adjusted according to the scale after the enlargement or reduction.

  After that, based on the setting value of each variable (center, viewsize, layer, tilesize), the tile image corresponding to the display range of the screen 23 is specified to obtain each file name, of which the server device 1 is still downloaded. The file name of the tile image that is not present (or the tile image that has been downloaded in the past but has already been deleted) is registered in the download queue (step S22). Here, the tile image corresponding to the display range of the screen 23 refers to a tile image partially or entirely included in the display range of the screen 23. In this example, since the tile image data downloaded from the server device 1 is stored in the tile data holding unit 25, whether or not the tile image holding unit 25 has been downloaded is referred to (or has been deleted). Can be determined.

Next, the download thread T2 will be described with reference to FIG.
In this example, the four download threads T2 (# 1) to (# 4) are operated in duplicate (in parallel), but the number of download threads T2 is arbitrary, and the processing performance of the mobile terminal 2 and the mobile communication network An appropriate number may be determined in consideration of various factors such as the communication performance of No. 3. Here, overlapping (parallel) operation may be a configuration in which each thread is operated in parallel using different processors, and the processing time of the processor is divided into very short units and assigned to each thread in order, A configuration in which each thread is operated in parallel by a common processor may be employed.
Since the operation contents of the download threads T2 (# 1) to (# 4) are common, the download threads are simply referred to as download threads T2 in the following without distinguishing each.

The download thread T2 extracts one file name from the download queue and sets it to tilename, which is a variable representing the file name of the tile image (step S31).
Next, it is determined whether or not the variable tilename is empty (whether or not the file name has been extracted from the download queue) (step S32). As a result, if it is determined that the variable tilename is not empty (the file name can be extracted), a tile image request for requesting a tile image whose file name is the variable tilename is transmitted to the server apparatus 1 through the communication interface unit 21. Then, the corresponding tile image data is downloaded (received) from the server device 1 and stored in the tile data holding unit 25 (step S33). At this time, in response to the reception of the tile image request from the portable terminal 2, the request processing unit 11 of the server device 1 receives the tile image data having the file name specified in the tile image request from the tile data holding unit 15. Processing to read and transmit to the requesting mobile terminal 2 is performed. The processing on the server device 1 side is also performed in duplicate according to the number of download threads T2 on the mobile terminal 2 side.
After downloading of the tile image in step S33, or when it is determined in step S32 that the variable tilename is empty (file name could not be extracted), the process returns to step S31.

  As described above, each download thread T2 monitors the download queue as needed, and extracts the registered file names one by one to download the corresponding tile image. When a plurality of file names are registered in the download queue by the main thread T1, the tile images are downloaded in duplicate (in parallel) by the plurality of download threads T2.

Next, the display thread T3 will be described with reference to FIG.
The display thread T3 reads the tile image data corresponding to the display range of the screen 23 from the tile data holding unit 15, and draws each tile image at an appropriate position on the screen 23 (step S41). In this example, whether or not the data of each tile image corresponding to the display range of the screen 23 has been downloaded is monitored at any time with reference to the tile data holding unit 15, and promptly every time the tile image is downloaded. The drawing is performed. In this example, the position on the screen 23 is obtained from the X position and Y position (arrangement information) in the file name of the tile image, and the tile image is drawn at the corresponding position.

For example, at the time of initial display, a plurality of tile images having the largest layer number are downloaded, and based on these tile images, a part or the whole of the entire image designated as a display target is displayed.
In addition, for example, when a user operation to slide the display range is performed, a plurality of tile images newly included in the display range by the display slide (a plurality of tile images adjacent to the currently displayed tile image) ) Is downloaded, and a new display range portion is displayed based on these tile images.
Further, for example, when a user operation for enlarging the display is performed, if the degree of the operation (magnification rate) is less than a predetermined threshold, the enlarged display is performed by image processing for enlarging the currently displayed tile image. Is called. On the other hand, when the predetermined threshold value is exceeded, a plurality of tile images having a larger scale (smaller layer number) than the currently displayed tile image are downloaded, and the display is switched to display using these tile images.
In addition, for example, when a user operation for reducing the display is performed, if the degree of the operation (reduction ratio) is less than a predetermined threshold, a plurality of items newly included in the display range due to display reduction Tile images (a plurality of tile images adjacent to the currently displayed tile image) are downloaded, and reduced display is performed by image processing for reducing the currently displayed tile image and the newly downloaded tile image. On the other hand, when a predetermined threshold value is exceeded, a plurality of tile images having a smaller scale (larger layer number) than the currently displayed tile image are downloaded, and the display is switched to display using these tile images.

  Note that the number of tile images necessary for screen display on the portable terminal 2 is substantially constant regardless of the degree of enlargement or reduction of the display. In this example, the vertical length of the screen 23 is divided by the tile size (vertical length), and the result is rounded up to the nearest decimal point. The number obtained by dividing the horizontal length of the screen 23 by the size of the tile (the horizontal length) and rounding up the result after the decimal point is used. By using the number of tile images obtained by such calculation, the screen 23 can be filled with tile images. Further, since the image formed by the above-mentioned number of tile images is slightly larger than the screen 23, the display range can be slid without downloading a new tile image within the margin.

Here, the tile data holding unit 15 of the server device 1 has a mechanism for continuously holding tile image data for a certain period of time, and even when a tiling request is received from the mobile terminal 2, tiling is performed. When tile image data based on the image instructed by the request exists in the tile data holding unit 15, the tiling process can be omitted.
In addition, the tile data holding unit 25 of the mobile terminal 2 has a mechanism for continuously holding tile image data for a certain period of time, and the user can perform operations such as sliding the display range and enlarging / reducing the screen 23. Even when the tile image corresponding to the display range changes, if the tile image data newly included in the display range exists in the tile data holding unit 25, the download process can be omitted.

Next, consider the size of the tile image.
FIG. 5 shows an example in which the size of the tile image is verified from the viewpoint of communication, efficiency, and usability.
When communication is verified, if the size of the tile image is large, the time required to download one tile image becomes longer. However, since the number of tile images used for screen display is reduced, communication is seen when viewing the entire image display. Less overhead. On the other hand, when the size of the tile image is small, the time required to download one tile image is shortened. However, since the number of tile images used for screen display increases, the overhead of communication is seen in the entire image display. large.

  When the efficiency is verified, if the size of the tile image is large, all of the tile images on the screen (display range) are to be downloaded, so that the display area is wasted. On the other hand, when the size of the tile image is small, there is little waste in display area.

  When the feeling of use is verified, when the size of the tile image is large, it takes a long time to download the tile image, and then the image is drawn at once. On the other hand, when the size of the tile image is small, the download of the tile image is fast, and therefore the impression of good response is received. However, if the size is too small, it takes a long time to finish drawing the entire image.

As described above, various factors are affected by the size of the tile image.
In this example, a square tile image of 256 × 256 is used in consideration of the overall balance. However, a tile image of another size may be used, for example, a tile according to the screen size of the mobile terminal 2 or the like. The image size may be changed. Further, instead of a square tile image, a rectangular tile image may be used.

Next, consider the number of download threads.
FIG. 6 shows a result of verifying the optimum number of threads in a 3G communication environment using a plurality of portable terminals 2 of different models. In the graph of FIG. 6, the horizontal axis is the number of threads, the vertical axis is the time (ms) required to download a plurality of tile images, and the average download time obtained from the download time for each model is plotted for each number of threads. It is. According to the figure, the average download time is the shortest when the number of threads = 4, and it can be seen that when four download threads are used, good download performance can be obtained with each type of portable terminal 2. Note that the appropriate number of threads may vary depending on the verification conditions.
In this example, 4 is used as the number of threads in view of the above verification result. However, other numbers of threads may be used. For example, the number of threads is changed according to the processing performance of the mobile terminal 2. Also good.

  As described above, in this example, the server apparatus 1 arranges a plurality of tile images (divided images) obtained by tiling (dividing into images in a lattice shape) an image to be displayed by the mobile terminal 2, and arrangement information indicating each arrangement. And a plurality of tile images corresponding to the display range of the screen 23 of the mobile terminal 2 are transmitted in response to a request from the mobile terminal 2, and the mobile terminal 2 is downloaded (received) from the server device 1. A plurality of tile images are displayed on the screen 23 according to the arrangement information associated with each tile image. That is, the portable terminal 2 handles the tile image that is a part of the image, not the entire image, thereby solving the limitation that only a limited memory capacity can be used.

  In this example, the mobile terminal 2 operates a plurality of download threads that request and download tile images one by one. That is, the server device transmits a plurality of tile images in parallel, and the portable terminal receives the plurality of tile images transmitted from the server device in parallel, whereby the processing performance of the portable terminal 2 and mobile communication The communication performance of the network 3 can be effectively used to solve the limitation that only a limited communication speed can be obtained.

  Further, in this example, a plurality of tile images having different scales are prepared, and a tile image having an appropriate scale is used in accordance with a user operation for enlarging or reducing the display of the terminal device 2. The number of tile images (number of tile images to be downloaded) used for display of can be made uniform.

  Therefore, according to the image display system of this example, it is possible to effectively increase the efficiency of image transmission even when wireless communication is performed using a low-speed communication line called the mobile communication network 3, and as a result, The operability (handling) of image browsing in the terminal device 2 can be improved. Note that the above technique is also effective in a situation where the communication speed is reduced due to a tight communication line or the like while using a relatively high-speed communication line such as WiFi.

  Here, in the server apparatus 1 of the present example, the dividing unit according to the present invention is realized by the function of the tiling unit 12, and the storage unit according to the present invention is realized by the function of the tile data holding unit 15, and according to the present invention. The transmission means is realized by the function of the request processing unit 11. Note that these functions can be realized on the computer of the server apparatus 1 by causing a processor to execute a program for the server apparatus according to the present invention, for example.

  In the portable terminal 2 of this example, the receiving means according to the present invention is realized by the function of the download processing unit 24, and the display means according to the present invention is realized by the function of the tile drawing unit 26. These functions can be realized on the computer of the mobile terminal 2 by causing a program for the mobile terminal according to the present invention to be executed by a processor, for example.

  In this example, the server device 1 itself has the image database 13, but the image database 13 may be provided in an external device that can communicate with the server device 1. Further, the tiling unit 12 is also provided in an external device, and the server device 1 receives the tile image from the external device and holds the tile image in the tile data holding unit 15, and the tile according to the request from the mobile terminal 2. It is good also as a structure which transmits an image.

1: server device 2: mobile terminal 3: mobile communication network 11: request processing unit 12: tiling unit 13: image database 14: communication interface unit 15: tile data holding unit
21: Communication interface unit 22: Operation input unit 23: Screen 24: Download processing unit 25: Tile data holding unit 26: Tile drawing unit

Claims (11)

In an image display system including a mobile terminal capable of communicating with a server device via a wireless communication network,
The server device
Storage means for storing a plurality of divided images generated by dividing a target image;
In response to a request from the mobile terminal, a transmission unit that transmits a divided image corresponding to the request to the mobile terminal,
The portable terminal is
Display means for displaying a part or the whole of the target image on the screen of the mobile terminal using a plurality of divided images;
Receiving means for requesting the server device for a plurality of divided images used for display by the display means, and receiving in parallel the plurality of divided images transmitted from the server device in response to the request;
An image display system characterized by that. The image display system according to claim 1,
The receiving means requests the server device for a plurality of divided images adjacent to the divided images displayed on the screen based on a user operation to slide the display on the screen, and responds to the request to the server. Receiving a plurality of divided images transmitted from the device in parallel;
An image display system characterized by that. The image display system according to claim 1 or 2,
The receiving means requests the server device for a plurality of divided images adjacent to the divided images displayed on the screen based on a user operation to reduce the display of the screen, and responds to the request to the server Receiving a plurality of divided images transmitted from the device in parallel;
An image display system characterized by that. The image display system according to claim 1 or 2,
The storage means stores a plurality of divided images generated by dividing the image for each of a plurality of images having different scales obtained by the reduction process on the target image,
The receiving means requests the server device for a plurality of divided images having a scale smaller than that of the divided images displayed on the screen based on a user operation for reducing the display on the screen, and in response to the request, Receiving in parallel a plurality of divided images transmitted from the server device;
An image display system characterized by that. The image display system according to any one of claims 1 to 4,
The storage means stores a plurality of divided images generated by dividing the image for each of a plurality of images having different scales obtained by the reduction process on the target image,
The receiving means requests the server device for a plurality of divided images having a scale larger than the divided images displayed on the screen based on a user operation for enlarging the display of the screen, and in response to the request, Receiving in parallel a plurality of divided images transmitted from the server device;
An image display system characterized by that. The image display system according to any one of claims 1 to 5,
The server device further includes a dividing unit that divides the target image to generate a plurality of divided images.
The storage means stores a plurality of divided images generated by the dividing means;
An image display system characterized by that. In a portable terminal that can communicate with a server device via a wireless communication network,
Display means for displaying a part or the whole of the target image on the screen of the mobile terminal using a plurality of divided images generated by dividing the target image;
Receiving means for requesting the server device for a plurality of divided images used for display by the display means, and receiving in parallel the plurality of divided images transmitted from the server device in response to the request;
A portable terminal characterized by comprising: To the computer of the portable terminal that can communicate with the server device via the wireless communication network,
A display function for displaying a part or all of the target image on the screen of the mobile terminal using a plurality of divided images generated by dividing the target image;
A receiving function that requests the server device for a plurality of divided images used for display by the display function, and receives a plurality of divided images transmitted from the server device in parallel in response to the request;
The portable terminal program for realizing the above. In a server device capable of communicating with a mobile terminal via a wireless communication network,
Storage means for storing a plurality of divided images generated by dividing a target image;
Transmission means for transmitting a plurality of divided images used when displaying a part or all of the target image on the screen of the portable terminal in parallel to the portable terminal in response to a request from the portable terminal When,
The server apparatus characterized by having. To a server computer that can communicate with a mobile terminal via a wireless communication network,
A storage function for storing a plurality of divided images generated by dividing a target image;
In response to a request from the mobile terminal, a transmission function for transmitting in parallel to the mobile terminal a plurality of divided images used when displaying a part or all of the target image on the screen of the mobile terminal When,
A server device program for realizing the above. In an image display method implemented by an image display system including a portable terminal capable of communicating with a server device via a wireless communication network,
The server device stores a plurality of divided images generated by dividing a target image;
The mobile terminal requests the server device for a plurality of divided images required when displaying part or all of the target image on the screen of the mobile terminal,
In response to a request from the mobile terminal, the server device transmits a plurality of divided images corresponding to the request in parallel to the mobile terminal,
The mobile terminal receives a plurality of divided images transmitted from the server device in parallel, and performs screen display using the received plurality of divided images.
An image display method characterized by the above.

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