JP2005157931A - Image search device and method, program, and storage media - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the image search time of a distributed image search system. <P>SOLUTION: One of a plurality of image search devices dispersed in the different partial spaces of predetermined feature quantities uses a request receiving means 21 to receive an image registration request or an image search request from a client, and uses a feature quantity calculation means 23 to calculate the feature quantity of a registered image or an image for search that corresponds to either the image registration request or the image search request received. Based on the partial space of the feature quantity calculated, a request transfer destination specifying means 24 is used to specify the image search device that registers or searches for the image. Registration/storage or search is done using one's own devices 25, 27, 28 or the image registration request or the image search request is transferred by a request transfer means 26 to another image search device specified. An image search result receiving means 29 is used to obtain search results from the another image search device and a response sending means 22 is used to send search result information to the client. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image search apparatus, an image search method, and a program used in a distributed image search system including a client computer connected to a network such as a LAN or the Internet, a document management apparatus (image database), and a plurality of image search apparatuses. And a storage medium.

  2. Description of the Related Art Conventionally, a distributed database system is known in which a database is held in each of a plurality of computers connected via a network and processed as a single database. In this distributed database system, when the data that matches the search conditions of the access request exists in multiple databases, the client computer is specified by the search requester in order to efficiently acquire all applicable data on the distributed database. The search request is accepted, and the search request is delegated to one or more connection destination server computers registered in advance. The delegation destination server computer responds to the search request from the client computer, and the server computer itself is also the client computer. The search request is autonomously delegated to another server computer registered in advance.

As described above, in the distributed database system, search server delegation and response to a client computer are repeated between server computers. Then, the client computer receives the search target data from the connection destination server computer or another server computer delegated from the connection destination server computer, and outputs it to the search requester. Thus, the corresponding data is automatically acquired from a plurality of distributed databases based on a single search request from the search requester (see Patent Document 1).
JP 2000-250918 A

  However, recently, the number of installation locations of servers has increased and the capacity of databases attached to the servers has increased, and the number of documents and images to be searched stored therein has become enormous. For this reason, like the distributed database described in Patent Document 1, if the search operation is left to the autonomous operation of the server (search device) and all the distributed databases are searched one after another, the search takes time. Became.

  Therefore, the present invention addresses (1) an increase in the number of image search devices distributed and an increase in the number of search target images stored in the image search device (database) in an image search device connected to a network. The first purpose is to enable image registration that enables efficient image search in a short time, thereby shortening the image search time. (2) To prevent search omission at that time Is the second purpose.

  The invention of claim 1 is an image search apparatus usable in an image search system for sharing image registration or image search among image search apparatuses distributed and arranged by subspaces of predetermined feature amounts. Or means for calculating a feature amount of a search image; means for specifying an image search device that performs image registration or image search based on the calculated partial space of the feature amount; and image registration request information in the specified image search device Or an image search apparatus comprising: means for transferring image search request information.

  According to a second aspect of the present invention, in the image search device according to the first aspect, the means for specifying an image search device that performs image registration or image search based on the subspace of the calculated feature amount includes the calculated feature amount. The image search device is characterized by specifying an image search device that holds a partial space of a feature quantity adjacent to the partial space together with the image search device of the partial space.

  The invention of claim 3 is an image registration or image search method in an image search device of an image search system that shares image registration or image search among image search devices distributed and arranged by subspace of predetermined feature amounts. A step of receiving image registration request information or image search request information from a client device; a step of calculating a feature amount of a registered image or search image included in the received image registration request information or image search request information; and a calculated feature A step of specifying an image search device that performs image registration or image search based on a partial space of an amount, and when the image search device is specified as an image search device, image registration or image search is performed, and another image search device is specified. A step of transferring image registration request information or image search request information to the specified image search device, and an image search from another specified image search device A step of acquiring the image identification number of fruit, an image retrieval method characterized by having a step of transmitting the image identification number of the image search results and or other image search results of its own color in the client device.

  The invention according to claim 4 is a program for causing a computer to execute the processing of each step according to claim 3.

  A fifth aspect of the present invention is a computer-readable recording medium on which the program according to the fourth aspect is recorded.

Effects corresponding to claims 1 and 3: Even if the number of image search devices distributed in the network increases and the number of search target images accumulated in the image search device (database) increases, efficient image search in a short time Can be registered, thereby shortening the image search time.
Effect corresponding to claim 2: Search omission can be eliminated while the image search time is shortened.
Effects corresponding to claims 4 and 5: A general-purpose image search apparatus can be easily made to function as an image search apparatus having the above-described effects.

  FIG. 1 is a block diagram of a distributed image search system in which the present invention is implemented. In the figure, an image processing device C1 is connected to a document management device R1 and a distributed arrangement via a telecommunication line T such as a LAN or the Internet. Connected to the image search devices S1, S2,.

  The image processing apparatus C1 is a client computer. When a user performs registration or search of an image, the user tries to register or search by connecting to the document management apparatus R1 by a mouse or key input operation while confirming the display on the computer screen. An image is acquired and transmitted to the image search apparatus S1 together with a registration request or a search request as an original image to be registered or searched for, that is, a registration key image or a search key image. The image search device S1 registers or searches the registration key image or search key image with its own device in response to the registration request or the search request, and further performs registration or search by specifying other image search devices S2, S3,. Make it. Then, the identification number of the image that is the search result of the specified image search device is received and transmitted to the image processing device C1 together with the identification number of the image that is the search result of the self-image search device. An image that is handled in the present invention is given an identification number (hereinafter, abbreviated as an image identification number) that makes the image uniquely identifiable, and the image is always handled together with the image identification number. The image processing device C1 sends this image identification information to the document management device R1. Since the document management apparatus R1 manages and accumulates images based on the image identification number, when the image identification number is received, the image corresponding to the image identification number is sent back to the image processing apparatus C1. In the present embodiment, only one document management device R1 is shown, but a plurality of document management devices R1 may be provided for each form and type of image.

  The communication method used in the above-mentioned network distributed image search system is SOAP (Simple Object Access Protocol) so that the image processing device C1, the document management device R1, and the image search devices S1 to Sn can communicate by a common remote procedure call method. ). The request receiving means of the image search device S1 waits for connection from the image processing device C1 at a predetermined HTTP port (80 or the like), and receives a SOAP request from the image processing device C1. The search result is transmitted as a SOAP response to the image processing apparatus C1 by the transmission means. SOAP is a standard recommended by the W3C (World Wide Web Consortium), which abstracts and describes procedure calls and search results using XML, and enables connection between heterogeneous systems. In this embodiment, SOAP is used. However, the present embodiment is not limited to the use of this standard.

Next, the image search apparatus according to this embodiment will be described.
FIG. 2 is a block diagram illustrating a hardware configuration of the image search apparatus. In FIG. 2, a central processing unit (hereinafter abbreviated as CPU) 1 controls various operations of the image search device, a ROM 2 stores a program for starting the image search device, and a RAM 3 for image search processing. Search result data is temporarily stored. The transmission / reception device 5 exchanges registration requests, search requests, and search results with the client computer C1 and other image search devices S2, S3,. An input device 6 such as a keyboard can input instructions for image registration, search, and the like, and a liquid crystal type display device 7 displays an image of the search result. Further, the hard disk type storage device 8 stores a program for performing search processing according to the present invention and various data in addition to the image feature amount, and the storage medium drive device 9 is a CD-ROM equipped with an image registration / search processing program. And the like are read out and stored in the storage device 8. Each of these devices is connected by a bus circuit 10.

Further, the configuration operation of the image registration / search processing means according to the embodiment of the present invention will be described.
FIG. 3 is a block diagram showing a configuration of image registration / search processing means realized by the image search apparatus.

  (Embodiment 1) When performing image registration, a user first accesses the document management apparatus R1 from the client computer C1 via the network T, and acquires a registered image (registration key image). The registration key image may be a thumbnail image. Since the image identification information is given to the image, when the registration key image is acquired, this image identification information is also acquired. The client computer C1 transmits the acquired registration key image from the transmission / reception device (not shown) of the client computer C1 to the image search device S1. When the user has already obtained the registration key image at hand, the image may be transmitted as it is to the image search device S1.

  In FIG. 3, when receiving a registration request including a registration key image from the client computer C <b> 1, the request receiving unit 21 of the image search device S <b> 1 passes this to the feature amount calculating unit 23.

  The feature amount calculating means 23 calculates the feature amount of the registration key image in the registration request and passes it to the request transfer destination specifying means 24 described later with reference to FIGS. When the request transfer destination specifying unit 24 specifies the image search device S1 as the request transfer destination, the calculated feature amount is stored in the feature amount storage unit 28 together with the image identification information by the image registration unit 27. The actual state of the feature amount storage means 28 is the storage device 8. When the image search devices S2, S3,... Are specified as request transfer destinations, the registration key image is transmitted to the corresponding image search device by the request transfer means 26 and stored in the image search device.

Next, the request transfer destination specifying unit 24 will be described with reference to FIGS.
FIG. 4 is a diagram showing the relationship between the image identification number of the registration key image and the feature amount.

  Here, the feature amount according to the present invention is calculated as a feature amount by dividing the colors constituting the image into several groups and occupying the entire image with the colors belonging to each group. That is, the feature amount space constituting the color is divided into several groups, and the ratio of the partial space belonging to each group to the feature amount space is calculated as the feature amount. In an image composed of three RGB planes, each pixel is represented by a set of numerical values representing the values of the respective planes. When each plane is divided into, for example, three sections, each pixel is represented by 3 (the degree of red). ) * 3 (degree of green) * 3 (degree of blue) = belonging to any of 27 groups. Accordingly, as the feature amount in this case, when the ratio of the number of pixels belonging to each group in the number of pixels of the entire image is calculated, a multidimensional numerical sequence (vector) composed of 27 elements is obtained.

  Since the distance between images can be conveniently defined by using the feature amount as the vector, the feature amount is calculated from a set of images to be registered or searched, and the search key image is calculated. However, a similar image can be searched by calculating a similar feature amount and selecting an image close to the distance. The above-described example of calculating the feature amount that divides the three planes into three is the simplest example, and the feature amount implemented in the present invention is not limited to this.

In order to simplify the explanation, a feature quantity for convenience represented by three numerical values is defined based on the feature quantity. First, the 27 groups are red, green, blue, all low, 2 low, 1 medium or high (6), 2 low (3), all medium, low, medium, high 1 ( 6), 2 in 1 are high (3), 2 are high, 1 is low or medium (6), all are high, and the order is determined. Thus, rows such as “red low, green low, blue low”... “Red middle, green middle, blue middle”... “Red high, green high, blue high” are obtained. Next, this is divided into three groups of nine pieces in order, and three large groups are formed. The ratio of the number of pixels belonging to each of these three large groups to the whole is expressed as a feature amount. Thus, the feature amount can be displayed by a set of three numerical values in which the sum of 0 to 9 is 10.
FIG. 4 is a diagram showing the relationship between the image identification number of the registered key image and the feature amount. In FIG. 4, the image with the image identification number 1 is represented by a set of three numerical values of feature amounts 1, 1, and 8. The image with the number 2 has the feature amount 3, 3, 4, the image with the image identification number 3 has the feature amount 4, 4, 2, and the image with the image identification number 4 has the feature amount 7, 2, 1, respectively. It shall be represented by a set of numbers. In this way, when the feature amount is represented by a set of a plurality of numerical values, the first numerical value is referred to as a first element of the feature amount. In the present invention, the transfer destination of the request is specified by the first element of the feature amount. Assuming that the image search device is configured as three image search devices that are distinguished by S1, S2, and S3, an image having a feature amount of 0 to 3 in the first element is the image search device S1, and the first element is the first element. Assume that the image search device S2 specifies an image with a feature amount from 4 to 6, and the image search device S3 specifies an image search device S3 as an image with a feature amount of the first element from 7 to 9. As a result, the image search apparatus S1 for the images with the image identification numbers 1 and 2, the image search apparatus S2 for the image with the image identification number 3, and the image search apparatus S3 for the image with the image identification number 4, respectively. It becomes.

  FIG. 5 is a table in which the transfer destination image search device is specified for each first element of the feature quantity, and the request transfer destination specifying unit 24 holds this table. Therefore, when the feature amount is calculated and the feature amount is passed to the request transfer destination specifying unit 24, the request transfer destination specifying unit 24 specifies a transfer destination image search device with reference to the table. When any one of the image search devices S2, S3,... Other than the self-image search device S1 is specified as the transfer destination image search device, the registration key image is transferred to the transfer destination image search device by the request transfer means 26. The

  According to the present embodiment, the image search devices S1, S2, and S3 that are dispersedly arranged are divided into partial spaces by the first element of the feature quantity constituting the color, and the registered key image is assigned to the partial space to which the feature quantity belongs. Therefore, the corresponding feature quantity can be searched in a short time.

  (Embodiment 2) When performing an image search, in this case as well as in the case of image registration, the client computer C1 acquires a search key image from the document management apparatus R1 and transmits it to the image search apparatus S1. Of course, when the search key image has already been obtained at hand, the image may be transmitted as it is to the image search device S1.

  The feature amount calculation unit 23 of the image search apparatus S1 calculates the feature amount of the search key image and passes it to the request transfer destination specifying unit 24. The request transfer destination specifying unit 24 specifies the transfer destination image search device by the same method as the method of specifying the transfer destination of the registration key image described above.

  When the request transfer destination specifying unit 24 specifies the image search device S1 as the request transfer destination, the calculated feature amount is passed to the image search unit 25, and the image search unit 25 stores the feature amount of the search key image and the feature amount. The similarities of the image feature amounts accumulated in the means 28 are compared to search for similar images. The image identification number of the search result is transmitted to the client computer C1 by the response transmission unit 21.

  When the image search devices S2, S3,... Are specified as request transfer destinations, the search key image is transmitted to the corresponding image search device by the request transfer means 26, and image search is performed in the image search device. The resulting image identification number is received by the image search result receiving means 29. The received search result is transmitted to the client computer C1 by the response transmission means 22.

  By transmitting the transmitted image identification number to the document management apparatus R1, the client computer C1 can acquire the images and thumbnail images managed by the document management apparatus R1 using the image identification numbers and can view them on the display screen. .

  When the request transfer destination specifying unit 24 specifies a request transfer destination, the request transfer destination specifying unit 24 specifies an image search device having a feature quantity adjacent to the feature quantity together with the image search apparatus having the calculated feature quantity. Can do. For example, in the above-described example, an image having a first feature value of 3 specifies the image search device S1 and may be similar to an image of 4 whose first element is different from 1. The device S2 may also be specified as the request transfer destination.

  When a plurality of image search devices are specified in this way, the image search device S1 integrates the search results, and transmits a predetermined upper number having a high degree of similarity to the client computer C1 as a search result.

  In order to specify the transfer destination from the feature amount, such a direct table-based method may be used. However, based on the registered image tendency known in advance, the feature amount section in which many images are registered is finely divided. Alternatively, the feature amount may be converted based on principal component analysis or the like.

  According to the present embodiment, the image search device S1, S2, or S3 of the first element of the corresponding feature amount is selected by the first element of the feature amount of the search key image, and the selected image search device searches for an image. Therefore, the search time can be shortened. In addition, when selecting simultaneously an image search apparatus that holds a partial space of feature amounts adjacent to a partial space of feature amounts of the search key image, it is possible to shorten the search time and perform a search without omission.

  FIG. 6 is a diagram illustrating a procedure of image registration and image search processing. The processing procedure will be described with reference to FIG. In the description, (S) represents a processing step. When the image search device S1 receives an image registration request or image search request from the client computer C1 (S1), it calculates a registration key image or a feature value of the search key image included in the received image registration request or image search request (S2). ), An image search device that performs image registration or image search based on the calculated partial space of the feature amount is specified (S3). When the device itself is specified as an image search device, image registration or image search is performed. When another image search device is specified, the image registration request or image search request is transferred to the specified image search device (S4). The image identification number of the image search result is acquired from the specified other image search device (S5), and the search result and / or the image identification number of the other search result are transmitted to the client computer C1 (S6). The process ends.

  In order to execute the above-described image registration and image search, the processing procedure is described as a computer program in a general-purpose program language, and this program is stored in an arbitrary disk such as a flexible disk, CD-ROM, DVD-ROM, or MO. The image registration and the image search according to the present invention can be easily performed by recording the image on the recording medium and causing the computer to read the image. In addition to recording the program on a recording medium, the program can be directly read by the computer of the image search apparatus via an arbitrary network such as the Internet or an intranet.

  The present invention can be used in a similar image search apparatus by the above-described system configuration.

1 is a block diagram of a distributed image search system in which the present invention is implemented. It is a block diagram which shows the hardware constitutions of the image search device of FIG. It is a block diagram which shows the structure of the processing means implement | achieved by the image search apparatus of FIG. It is a figure which shows the relationship between the image identification number of a registration key image, and the feature-value. It is a figure which shows the example of the table which specifies the transfer destination image search apparatus according to feature-value. It is a figure which shows the procedure of a process of an image registration and an image search.

Explanation of symbols

  1 .... CPU, 2 .... ROM, 3 .... RAM, 5 .... Transceiver, 6..Operation panel, 7..Display device, 8 .... Storage device, 9 .... Storage medium drive device, 10 .... Bus circuit.

Claims (5)

An image search apparatus that can be used in an image search system that shares image registration or image search among image search apparatuses that are distributed and arranged by subspace of predetermined feature amounts,
Means for calculating a feature amount of a registered image or a search image;
Means for specifying an image search device for performing image registration or image search based on the calculated partial space of the feature amount;
Means for transferring image registration request information or image search request information to the specified image search device;
An image search apparatus comprising: The image search device according to claim 1,
The means for specifying an image search device that performs image registration or image search based on the calculated feature amount subspace includes the feature amount adjacent to the subspace together with the image search device of the calculated feature amount subspace. An image search device that identifies an image search device that holds a partial space. In an image search method in an image search device of an image search system for sharing image registration or image search among image search devices distributed and arranged by subspace of predetermined feature amounts,
Receiving image registration request information or image search request information from a client device;
Calculating a feature amount of a registered image or search image included in the received image registration request information or image search request information;
Identifying an image search device that performs image registration or image search based on the calculated partial space of the feature amount; and
A process of performing image registration or image search when the device itself is specified as an image search device, and transferring image registration request information or image search request information to the specified image search device when another image search device is specified. When,
Obtaining an image identification number of an image search result from another specified image search device;
Transmitting an image search result from the user and / or an image identification number of another image search result to the client device;
An image search method characterized by comprising: The program for making a computer perform the process of each process of Claim 3. A computer-readable recording medium on which the program according to claim 4 is recorded.

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