JP2014092909A - Image retrieval device, image retrieval method and image retrieval program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image retrieval device, etc. capable of obtaining a search result reflecting a user's intention.SOLUTION: The image retrieval device includes a classification unit, a first display control unit, a selection acceptance unit, a priority judgment unit and a second display control unit. The classification unit classifies the same image group under a plurality of classification conditions with a plurality of classification patterns. The first display control unit displays the classification result with the plurality of classification patterns. The selection acceptance unit, after the classification result is displayed, accepts selection of a specified classification pattern and/or a specified image group out of the plurality of classification patterns and/or a plurality of image groups defined by the plurality of classification patterns. The priority judgment unit judges priority of an image contained in the image group according to the specified classification pattern and/or the specified image group. The second display control unit displays an image contained in the image group according to the priority.

Description

  The present invention relates to an image search apparatus, an image search method, and an image search program for searching for an image desired by a user from an image group.

  Conventionally, various techniques for retrieving an image desired by a user from an image group have been proposed. In such a technical field, in addition to the point of how to search for an image requested by the user from a large group of images, the order in which the searched images are presented to the user. Is also an important research theme. For that purpose, how to grasp the user's request and how to realize the search according to the request become a big problem.

  In Patent Document 1, an image group is searched from a search target image group using a text query input by a user as a key, and the searched image group is classified into a plurality of image groups by a method such as clustering. It is disclosed. Further, Patent Document 1 also discloses that the result of this classification is presented to the user, and then the selection of a specific image group is accepted from the user, and only the images belonging to the selected image group are displayed on the screen. Yes.

JP 2011-154687 A

  As described above, in Patent Document 1, in order to narrow down the search results, after the image group is classified into a plurality of image groups, the user is allowed to select a desired image group. It has been. In other words, in Patent Document 1, the image group is only classified in one way from one viewpoint.

  By the way, even when searching for an image using the same query, the search result requested by the user differs depending on the TPO. For example, when the user is looking for a butterfly image, the search result to be presented to the user differs depending on whether the user is paying attention to the outline of the butterfly or the pattern of the butterfly wings. come. Therefore, as in Patent Document 1, if the image group is classified only under one classification condition, that is, only one way from one viewpoint, what the user really wants is sufficient for the final search result. The problem that it cannot be reflected may arise. For example, when a user is looking for an image of a butterfly having a specific external shape (the tip of the wing is sharp, the tip of the wing is rounded, etc.), the image group is classified from the viewpoint of the shape of the butterfly. Otherwise, the result of the classification will not match the user's intention. As described above, the user's request changes depending on the TPO, and changing the search result following the change is a strong request from the user.

  An object of the present invention is to provide an image search apparatus, an image search method, and an image search program that can obtain a search result according to a user's intention.

  An image search apparatus according to a first aspect of the present invention includes a classification unit, a first display control unit, a selection receiving unit, a priority determination unit, and a second display control unit. The classification unit classifies the same image group with a plurality of classification patterns according to a plurality of classification conditions. The first display control unit displays the result of the classification with the plurality of classification patterns. After the display of the classification result, the selection reception unit receives a specific classification pattern and / or a specific classification from a plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns. Accept image group selection. The priority determination unit determines a priority of an image included in the image group according to the specific classification pattern and / or the specific image group. The second display control unit displays images included in the image group according to the priority. Here, the “image group” corresponds to A2 in the example of the screen displaying the classification result, and “classification pattern” corresponds to A1 in which a plurality of A2s are collected. . Therefore, in FIG. 7, two classification patterns based on two classification conditions are displayed.

  Here, the same image group is classified according to different classification patterns according to different classification conditions, whereby different classification results are presented to the user. Furthermore, a specific classification pattern and / or a specific image group is selected by the user who sees the result of the classification, and the priority of the image presented to the user as a search result is determined according to the content of the selection. Is done.

  That is, here, the image group to be searched is classified into a plurality of ways from a plurality of viewpoints. Then, upon receiving the results of these multiple classifications, the user can select a specific classification pattern. This selection is based on the classification according to the user's intention from a plurality of classification viewpoints. This means selecting a viewpoint. Therefore, for example, when the classification in terms of the outer shape of the butterfly and the classification in terms of the pattern of the butterfly wings are shown, the user selects the classification pattern corresponding to the former classification, so that the butterfly You can indicate that you are paying attention to the outer shape of the butterfly, not the wing pattern. Alternatively, the user may select a specific group of images instead of or in addition to a specific classification pattern, but this selection allows the user to select (at least) the image he / she wants as a search criterion according to his / her intention. (In general) means selecting a group of images to be bundled. In the previous example of butterflies, the user selects a specific image group from a plurality of image groups classified by the shape of the butterfly, thereby making the specific outline (the tip of the wing sharp, It is possible to indicate that the user is paying attention to a butterfly having a rounded tip.

  As described above, the user can specify a classification viewpoint and / or a search criterion according to his / her intention by selecting a specific classification pattern and / or a specific image group. Therefore, it is possible to obtain a search result according to the user's intention.

  The image search device according to the second aspect is the image search device according to the first aspect, and further includes a query receiving unit. The query receiving unit receives a query image specification from the user. The first display control unit preferentially displays an image belonging to the image group having a high similarity to the query image from the image group for each classification pattern, thereby obtaining the classification result. indicate. Here, it is not necessary to display all the images belonging to the image group having a high degree of similarity with the query image, and a part of the images belonging to the image group may be displayed as the representative image.

  Here, the query image is designated by the user, and thereafter, when displaying the result of classifying the image group, the images belonging to the image group similar to the query image are preferentially displayed. Therefore, a user who sees the result of classification of the image group can easily specify a classification pattern and / or an image group according to his / her intention.

  Note that the similarity between the image group and the query image can be determined, for example, according to the distance between the point indicating the query image and the center of gravity of the region indicating the image group in the classification space defined by the classification condition. it can. In addition, an image group in an area where a point indicating a query image exists in the classification space may be determined as an image group having a high similarity to the query image. Furthermore, the classification space here may be a one-dimensional space or a multi-dimensional space.

  An image search device according to a third aspect is the image search device according to the second aspect, wherein the priority determination unit, when the selection reception unit receives a selection of the specific classification pattern from a user, Among the image groups defined by the classification pattern, the priority of images belonging to a similar image group having a high similarity to the query image is set high.

  Here, images belonging to an image group similar to the query image from the viewpoint of classification specified by the user are preferentially displayed as search results. Therefore, it is possible to obtain a search result more in line with the user's intention.

  An image search device according to a fourth aspect is the image search device according to the third aspect, wherein the selection receiving unit receives selection of a plurality of the specific classification patterns. The priority determination unit specifies the similar image group for each of the specific classification patterns, and belongs to a group defined by a set operation of the plurality of similar image groups respectively corresponding to the plurality of specific classification patterns. The image priority is set high. The set operation is a known set operation such as logical sum, logical product, logical difference, exclusive logical sum, and the like.

  Here, the user can select a plurality of classification patterns according to his intention. Then, when a plurality of classification patterns are selected by the user, a plurality of similar image groups respectively corresponding to these classification patterns are specified, and then a group defined by a set operation of these similar image groups as a search result The images belonging to are preferentially displayed. Therefore, the user can specify his / her intention by combining a plurality of classification viewpoints.

  An image search device according to a fifth aspect is the image search device according to any one of the first to fourth aspects, wherein the priority determination unit selects the specific image group from the user by the selection reception unit. Is received, the priority of the images belonging to the specific image group is set high.

  Here, images belonging to the image group designated by the user are preferentially displayed as search results. Therefore, it is possible to obtain a search result more in line with the user's intention.

  An image search device according to a sixth aspect is the image search device according to the fifth aspect, wherein the selection receiving unit receives selection of a plurality of the specific image groups. The priority determination unit sets the priority of an image belonging to a group defined by a set operation of the plurality of specific image groups to be high. The set operation is a known set operation such as logical sum, logical product, logical difference, exclusive logical sum, and the like.

  Here, the user can select a plurality of image groups according to his / her intention. When a plurality of image groups are selected by the user, images belonging to a group defined by a set operation of these image groups are preferentially displayed as search results. Therefore, the user can specify his / her intention by combining a plurality of image groups.

  An image search device according to a seventh aspect is the image search device according to the second aspect, wherein the selection receiving unit receives selection of the specific classification pattern and the specific image group. The priority determination unit specifies a similar image group having a high similarity to the query image among the image groups defined by the specific classification pattern, and determines the similarity between the similar image group and the specific image group. The priority of the images belonging to the group defined by the set operation is set high. The set operation is a known set operation such as logical sum, logical product, logical difference, exclusive logical sum, and the like.

  Here, the user can select a combination of classification patterns and image groups according to his / her intention. When both the classification pattern and the image group are selected by the user, first, a similar image group similar to the query image is specified from among a plurality of groups defined by the classification pattern. After that, as a search result, images belonging to a group defined by a set operation of the similar image group and the image group designated by the user are preferentially displayed. Therefore, it is possible to obtain a search result more in line with the user's intention.

  An image search device according to an eighth aspect is the image search device according to any one of the second to seventh aspects, wherein the selection receiving unit receives the specific classification pattern and / or the specific image from a user. By accepting the selection of the group, the selection of the classification condition is accepted, and the designation of the weight of the classification condition is accepted. When the selection receiving unit receives a plurality of selections of the specific classification condition from a user, the priority determination unit applies the weight to the image group under the specific classification conditions weighted according to the weight. The similarity between the included image and the query image is determined, and the priority is determined according to the similarity.

  Here, the user can select a classification condition in accordance with his / her intention and designate the weight. Then, when a plurality of classification conditions are selected by the user, the classification conditions are weighted according to the weights specified by the user, and then the search target The similarity between the image included in the image group and the query image is determined. After that, as a search result, an image with a high similarity is preferentially displayed. Therefore, it is possible to obtain a search result more in line with the user's intention.

  An image search apparatus according to a ninth aspect is the image search apparatus according to any of the first to eighth aspects, wherein the classification condition is a feature quantity description that is one feature quantity or a combination of a plurality of feature quantities Defined by children. Therefore, here, the abstract concept of the viewpoint of classification can be quantitatively expressed so that it can be understood by a device such as a computer.

  An image search method according to a tenth aspect includes a step of classifying the same image group with a plurality of classification patterns according to a plurality of classification conditions, a step of displaying a result of classification with the plurality of classification patterns, and a result of the classification Receiving a selection of a specific classification pattern and / or a specific image group from the plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns after the display of Determining a priority of an image included in the image group according to the specific classification pattern and / or the specific image group; and displaying an image included in the image group according to the priority; Is provided.

  Here, the same image group is classified according to different classification patterns according to different classification conditions, whereby different classification results are presented to the user. Furthermore, a specific classification pattern and / or a specific image group is selected by the user who sees the result of the classification, and the priority of the image presented to the user as a search result is determined according to the content of the selection. Is done.

  As described above, the user can specify a classification viewpoint and / or a search criterion according to his / her intention by selecting a specific classification pattern and / or a specific image group. Therefore, it is possible to obtain a search result according to the user's intention.

  An image search program according to an eleventh aspect includes a step of classifying the same image group with a plurality of classification patterns according to a plurality of classification conditions, a step of displaying a result of classification with the plurality of classification patterns, and a result of the classification Receiving a selection of a specific classification pattern and / or a specific image group from the plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns after the display of Determining a priority of an image included in the image group according to the specific classification pattern and / or the specific image group; and displaying an image included in the image group according to the priority; Is executed on the computer.

  Here, the same image group is classified according to different classification patterns according to different classification conditions, whereby different classification results are presented to the user. Furthermore, a specific classification pattern and / or a specific image group is selected by the user who sees the result of the classification, and the priority of the image presented to the user as a search result is determined according to the content of the selection. Is done.

  As described above, the user can specify a classification viewpoint and / or a search criterion according to his / her intention by selecting a specific classification pattern and / or a specific image group. Therefore, it is possible to obtain a search result according to the user's intention.

  According to the present invention, the same image group is classified according to different classification patterns according to different classification conditions, whereby the result of different classification is presented to the user. Furthermore, a specific classification pattern and / or a specific image group is selected by the user who sees the result of the classification, and the priority of the image presented to the user as a search result is determined according to the content of the selection. Is done. As described above, the user can specify a classification viewpoint and / or a search criterion according to his / her intention by selecting a specific classification pattern and / or a specific image group. Therefore, it is possible to obtain a search result according to the user's intention.

1 is a schematic configuration diagram of an image search system according to an embodiment of the present invention. It is a block diagram which shows the structure of an image server. It is a block diagram which shows the structure of an information terminal. It is a figure which shows the data structure of a feature database. It is a sequence diagram which shows the flow of an image search. (A) It is a figure which shows the example of the image group used as search object. (B) It is a figure which shows the example of a query image. It is a figure which shows the example of a selection screen. It is a figure which shows the example of a search result screen.

Hereinafter, an image search apparatus, an image search method, and an image search program according to an embodiment of the present invention will be described with reference to the drawings.
<1. Schematic configuration>
As shown in FIG. 1, an image search system 1 that is an image search apparatus according to this embodiment is connected to an image server 2 and a network 6 such as a local area network (LAN) or the Internet. Various information terminals 3 are provided. The information terminal 3 is a device used for a user's operation for searching for an image. The image search system 1 is a system for searching for an image desired by a user from among a huge image group stored in the image server 2 mainly using a query image specified by the user via the information terminal 3 as a key. . The image search system 1 can interactively grasp a user's intention and present a search result in accordance with the user's search purpose to the user.

  The image server 2 is a general server computer as hardware. The image server 2 is manufactured by installing the image search program 2A on this general server computer and storing a group of images to be searched. The image search program 2A is a program that causes the image server 2 to execute processing to be described later. The image search program 2A is a computer-readable recording medium 70 such as a CD-ROM, DVD-ROM, Blu-ray disc, USB memory, or the like. Installed from another device. Note that the functions of the image server 2 may be distributedly processed by a plurality of server computers or may be centrally processed by a single server computer. That is, the hardware configuration of the image server 2 is not subject to the restriction that at least one server computer exists.

  The information terminal 3 is a general personal computer or a smartphone that can be connected to the network 6 as hardware, and is manufactured by installing a predetermined program 3A in these general devices. The program 3A is a program for causing the information terminal 3 to execute processing to be described later, and is separated from a computer-readable recording medium 80 such as a CD-ROM, DVD-ROM, Blu-ray disc, USB memory, or the like via the network 6. Installed from other devices. The program 3A is application software for establishing a connection with the image server 2 and executing a part of the image search process in cooperation with the image server 2, and is a simple browser in the present embodiment. Therefore, in the present embodiment, all processes other than displaying various screens are performed by the image server 2 in principle, and the information terminal 3 mainly receives various screens created by the image server 2 from the image server 2 and displays them. Perform processing only. However, in another embodiment, an arbitrary function described later that is implemented in the image search program 2A may be implemented in the program 3A, and processing performed by the image server 2 may be distributed to the information terminals 3. Hereinafter, the configuration of each apparatus will be described.

<2. Details of each device>
<2-1. Image server>
As shown in FIG. 2, the image server 2 includes a control unit 21, a storage unit 22, and a communication unit 23. These units 21 to 23 are connected to each other via the bus line 7 and can communicate with each other.

  The storage unit 22 is composed of a non-volatile storage device such as a hard disk or a magnetic tape, and stores an image search program 2A and an image database 50 and a feature database 55. In the image database 50, an image group to be searched is stored. Details of the databases 50 and 55 will be described later.

  The control unit 21 includes a CPU, a ROM, a RAM, and the like. The control unit 21 reads and executes the image search program 2A stored in the storage unit 22 to virtually execute the feature extraction unit 21A, the classification unit 21B, the query reception unit 21C, the similarity determination unit 21D, and the selection It operates as a reception unit 21E, a priority determination unit 21F, a first display control unit 21G, and a second display control unit 21H. Details of the operations of the respective units 21A to 21H will be described later.

  In addition to connecting the image server 2 to the network 6, the communication unit 23 functions as a communication interface that receives data from an external storage device such as a USB memory or a memory card. Therefore, the communication unit 23 plays a role of transmitting / receiving a query image and a search result to / from the information terminal 3 via the network 6.

<2-2. Information terminal>
As illustrated in FIG. 3, the information terminal 3 includes a display unit 31, an input unit 32, a storage unit 33, a control unit 34, and a communication unit 35. These units 31 to 35 are connected to each other via the bus line 8 and can communicate with each other. In the present embodiment, the display unit 31 is configured by a liquid crystal display or the like, and is a user interface that displays a screen or the like described later to the user. The input unit 32 includes a mouse, a keyboard, a touch panel, operation buttons, and the like. The input unit 32 is a user interface that receives an operation from the user with respect to the information terminal 3 and eventually the image server 2 connected thereto.

  The storage unit 33 is composed of a nonvolatile storage device such as a hard disk or a flash memory, and stores a program 3A. The control unit 34 includes a CPU, a ROM, a RAM, and the like. The communication unit 35 functions as a communication interface that connects the information terminal 3 to the network 2 and receives data from an external storage device such as a USB memory, a memory card, a CD-ROM, an external hard disk, or a digital camera. Therefore, the communication unit 35 plays a role of transmitting / receiving a query image and a search result to / from the image server 2 via the network 6.

<3. Operation>
Hereinafter, the operation of the image search system 1 will be described.
<3-1. Preparation of images to be searched>
First, when starting an image search by the image search system 1, data of an image group to be searched is stored in the image database 50. At this time, the image group stored in the image database 50 is stored in an input device such as a mouse or a keyboard directly connected to the image server 2 or a communication unit 23 manually or automatically by an administrator having access authority. Is input via.

  In the image database 50, a new image is added or a part is deleted suitably. Each time a new image is added to the image database 50, or periodically or at an arbitrary timing, the feature extraction unit 21A uses the image data as a parameter value indicating the feature of each newly added image. The value of a predetermined feature descriptor is calculated from Here, the feature amount descriptor is one feature amount or a combination of a plurality of feature amounts. In the present embodiment, the feature amount descriptor has a one-to-one correspondence with the feature amount included in the definition of the feature amount descriptor. Is a one-dimensional or multi-dimensional scale. Therefore, the value of the feature descriptor of each image can be expressed as a one-dimensional or multi-dimensional vector having one or a plurality of feature values as elements. Represented by points in a multidimensional classification space.

  Feature descriptors are, for example, Fourier descriptors, Zeronike polynomials, Markov transition probabilities, texture features (higher moments, contrast, correlation, homogeneity, entropy, difference, mean, variance, etc.), co-occurrence matrices, curvature measures It may be defined by appropriately using a known scale that represents the feature of an image, such as a space representation (CSS: Curvature Scale Space). Note that high-order moments, co-occurrence matrices, Fourier descriptors, etc. are descriptors suitable for representing the characteristics of the shape of the feature region in the image. A region-based descriptor suitable for representing, and a Fourier descriptor, CSS, is a contour-based descriptor suitable for representing contour features. These shape-based descriptors are particularly useful when the image to be searched is not a color image, but a black and white image, or even a color image that has relatively little color change. Can be accurately represented. In general, searching for black-and-white images is more difficult than searching for color images, but it is relatively easy to search for black-and-white images by using the shape-based descriptor as described above. Can be realized.

  Here, the feature extraction unit 21A calculates values of a plurality of types of feature descriptors for each image. In addition, the feature extraction unit 21A stores a plurality of types of feature descriptor values for each image in the feature database 55 in association with the images. Hereinafter, a plurality of feature descriptors are represented as D1, D2,. In the present embodiment, the feature database 55 is a tabular database shown in FIG. 4, and the records in the feature database 55 correspond one-to-one to the images stored in the image database 50. 4, in the feature database 55, the values of a plurality of feature descriptors D1, D2,... Are stored in association with the image IDs of the images stored in the image database 50. Since the image server 2 not only stores the numerical value as a result in the feature database 55 but also implements an algorithm for deriving the result as the image search program 2A, a feature descriptor for an unknown image The value of can be calculated.

  Now, each time the record in the feature database 55 is updated or periodically or at an arbitrary timing, the classification unit 21B selects a plurality of image groups in the image database 50 in a plurality of classification patterns according to a plurality of classification conditions. Classify into: Specifically, the classification unit 21B classifies all the values of the feature descriptors stored in the feature database 55 into a plurality of groups for each of the feature descriptors D1, D2,. The image group in the image database 50 is classified into a plurality of image groups. Therefore, the classification conditions for the plurality of types of classification processing executed here are determined by the feature descriptors D1, D2,. The classification pattern by the classification process executed here corresponds to a division pattern for dividing the classification space defined by the feature descriptor.

  Any known cluster analysis algorithm can be employed for image classification. For example, the K-means method, which is a non-hierarchical clustering method, may be employed, but other methods may be employed regardless of hierarchical or non-hierarchical methods. In this embodiment in which the K-average method is adopted, there is no overlap between image groups, but a classification method in which image groups can partially overlap can also be adopted.

  When the classification process is completed, the classification unit 21B stores the classification result in the feature database 55. Specifically, the classification unit 21B stores the image group ID of the image group to which each image belongs in the feature database 55 in association with the image for each of the feature descriptors D1, D2,. As shown in FIG. 4, in the feature database 55, a field is defined in which an image group ID corresponding to the image ID of each image can be stored for each of the feature descriptors D1, D2,. Further, the classification unit 21B obtains, for each feature amount descriptor D1, D2,..., Data (hereinafter referred to as region data) that defines the range of the region corresponding to each image group in the classification space. Are stored in the storage unit 22 in association with the image group ID.

  As described above, the image in the image database 50 may be deleted. In this case, the record corresponding to the image in the feature database 55 is also deleted.

<3-2. Image search>
Next, the flow of image search using the image search system 1 will be described with reference to FIG.

  First, the user operates the input unit 32 of the information terminal 3 to identify or specify a query image Q1 serving as a search key or an image ID thereof (including an image storage location and a file name). As an arbitrary information for storing the information terminal 3 or a device connected to the information terminal 3 (separate personal computer, USB memory, memory card, CD-ROM, external hard disk, digital camera, etc.) The image itself or the image ID stored in the arbitrary device) is designated (step S1). In response to this operation, the communication unit 35 of the information terminal 3 transmits the query image Q1 to the image server 2 via the network 6 (step S2). At this time, the query image Q1 is received by the query receiving unit 21C via the communication unit 23. As a method for specifying the query image Q1, an image on the Internet 6 can also be specified. In this case, the communication unit 35 may once download the query image Q on the Internet 6 and transmit it to the query receiving unit 21C, or notify the image server 2 only of the URL where the query image Q1 exists. The query reception unit 21C may download the query image Q1 from the URL.

  Subsequently, in step S3, the feature extraction unit 21A of the image server 2 calculates values of a plurality of types of feature descriptors D1, D2,... For the query image Q1.

  Next, the similarity determination unit 21D calculates the similarity with the query image Q1 for each image group in the classification pattern corresponding to the feature descriptor for each feature descriptor D1, D2,. To do. This calculation is executed based on the values of the feature descriptors D1, D2,... Of the query image Q1 and the above-described area data in the storage unit 22. The similarity between the image group and the query image Q1 can be determined by various methods. For example, the similarity is determined as a distance between a point indicating the query image Q1 in the classification space and the center of gravity of the region indicating the image group. (The smaller the distance, the higher the degree of similarity). It is also possible to determine an image group in an area where a point indicating the query image Q1 exists in the classification space as an image group having the highest similarity with the query image Q1. Alternatively, the determination can be made according to the number of images having a similarity equal to or higher than a predetermined reference from the query image Q1 included in the image group or the ratio thereof. The similarity determination unit 21D has the top N (N = 1, 2,...) Having a high similarity to the query image Q1 for each feature descriptor D1, D2,... According to the calculated similarity. Image groups C1,... CN are identified (step S4). Note that the value of N may be determined in advance, or may be a value that is determined in a fluid manner according to the degree of similarity between the image group and the query image Q1. In the latter case, the value of N may be different for each of the feature descriptors D1, D2,.

  Also, the similarity determination unit 21D represents the image group for each of the top N image groups C1,... CN identified in step S4 for each of the feature descriptors D1, D2,. M representative images R1,... RM are identified (step S5). The representative images R1,... RM have a high similarity to the query image Q1 among the images belonging to the image group in the image group to be searched (hereinafter referred to as image groups I1, I2,...). It is specified as the top M images. Here, the similarity between images is determined, for example, as a distance between two points indicating the images in the classification space (the smaller the distance, the higher the similarity). Note that the calculation here includes the values of the feature descriptors D1, D2,... Of the query image Q1 calculated in step S3, and the image groups I1, I2,. This is executed based on the values of the feature descriptors D1, D2,. Note that the specific method of the representative images R1,... RM is not limited to the method of selecting the top M images having high similarity as described above. For example, the characteristics of the image group are expressed as much as possible. A method of picking up representative images R1,. For example, if there are several peaks in the image distribution within the region corresponding to the image group, the characteristics of the image group can be expressed by selecting the image at the center of the peak. On the other hand, when the image is widely dispersed in the region corresponding to the image group, instead of selecting only the image near the center of the region, by selecting the image dispersed from the entire region, The characteristics of the image group can be expressed.

  Next, the 1st display control part 21 produces selection screen W1 (refer FIG. 7), transmits this to the information terminal 3 via the network 6, and displays it on the display part 31 (step S6). On the selection screen W1, M belonging to each of the top N image groups C1,... CN having high similarity to the query image Q1 from the image groups I1, I2,. One representative image R1,... RM is displayed. Therefore, on the selection screen W1, a plurality of classification results with a plurality of classification patterns by a plurality of feature descriptors D1, D2,. In FIG. 7, two classification results based on two classification patterns are shown, but it goes without saying that three or more classification results based on three or more classification patterns may be shown. Here, for each classification pattern, images belonging to the top N image groups C1,... CN are displayed with priority over images belonging to other image groups.

  Further, on the selection screen W1, the representative images R1,... RM belonging to the same image group are grouped in such a manner that it can be seen that they belong to the same image group (in the example of FIG. Displayed).

  In addition, on the selection screen W1, it is possible to recognize the degree of similarity between the image groups C1,... CN and the query image Q1 (in the example of FIG. 7, the similarity between the image groups C1,. The representative images R1,... RM are displayed in order from the left). As a result, on the selection screen W1 in FIG. 7, images that have a higher similarity to the query image Q1 and are more likely to be desired by the user are arranged in order from the left.

  Further, as is clear from the above, here, M representative images R1,... RM are displayed with priority over other images belonging to the same image group. As described above, the image groups C1,... CN are the top N image groups selected from the viewpoint of the similarity with the query image Q1, but the images belonging to these image groups C1,. Even so, not all images are similar to the query image Q1. Here, among the images belonging to the image groups C1,... CN selected as having a high similarity with the query image Q1, the representative images R1, selected as having a high similarity with the query image Q1. ... Only RM is displayed. Thereby, in the limited space of selection screen W1, an image with high possibility that a user desires can be arranged efficiently.

  By the way, the feature descriptors D1, D2,... That define the classification pattern are indices representing the viewpoint of classification. Here, the viewpoint of classification will be described in detail with reference to the example of FIG. 7. The result of the classification of the area A1 in FIG. 7 is the classification of whether the center of the feature region in the image is bent. Represents the point of view. On the other hand, the result of classification of the area A1 in the lower part of FIG. 7 represents the viewpoint of classification of whether or not the tip of the feature region in the image is pointed like a star. Note that the selection screen W1 in FIG. 7 is obtained when the query image Q1 is the bone image shown in FIG. 6B and the search target is the image groups I1, I2,... Shown in FIG. It is a screen.

  Next, returning to the description of step S6, after the selection screen W1 is presented to the user, the selection receiving unit 21E receives a specific classification pattern and / or a specific image group from the user via the selection screen W1. Accept selection. As described above, the result of classification by a plurality of classification patterns is displayed on the selection screen W1 and belongs to each of the N image groups C1,... CN respectively defined by these classification patterns. Representative images R1,... RM are displayed. Therefore, the user can select a specific classification pattern and / or a specific image group from among the plurality of classification patterns and the plurality of image groups. Note that, on the selection screen W1, an area A1 for displaying the result of classification according to each classification pattern is made into an object, and the user can select it. Further, an area A2 for displaying the representative images R1,... RM of each image group is also made into an object, and the user can select it.

  Here, as described above, each area A1 displays a classification result from the viewpoint of a specific classification. Therefore, selecting the specific area A1 means that the user selects a specific classification viewpoint according to his / her intention from a plurality of classification viewpoints. In addition, selecting a specific area A2 means that the user wants an image he / she wants from among various image groups classified from various viewpoints as a specific search criterion in accordance with his / her intention (at least (In general) means selecting a group of images to be bundled.

  By the way, in the field of image search, it is very important to let the device understand what sort of viewpoint and / or search criteria the user wants when searching for an image desired by the user. It is done. In general, it is difficult to hear this from the user and let the apparatus understand it. However, in the image search system 1, this is realized through selection of a classification pattern and / or an image group by the user. That is, in the present embodiment, since the feature descriptor used for classification is information held in advance by the device, the device describes the feature description corresponding to the classification pattern and / or image group selected by the user. By searching for an image according to the child, it is possible to obtain a search result that naturally matches the user's intention.

  As described above, the selection screen W1 accepts selection of an arbitrary number of selection elements (classification patterns and / or image groups) via the areas A1 and A2. However, when a plurality of selection elements are selected, the selection screen W1 allows the user to select which of “AND” and “OR” is used to combine these selection elements. On the selection screen W1, “AND” or “OR” is selected via the area A3 (see FIG. 7).

  Here, selecting “AND” after selecting a plurality of classification patterns means that the user selects a logical product from the viewpoint of classification, and selecting “OR” It means selecting the logical sum of viewpoints. This will be described with reference to the example of FIG. 7 again. For example, when the upper and lower areas A1 are selected by “AND” on the selection screen W1, the user can select the shape of the bone center (for example, the bone center It means that it is paying attention to the shape of the bone tip (for example, that it is not pointed like a star). On the other hand, selecting the upper and lower areas A1 by “OR” means that the bone image to be searched may be either straight or bent at the center of the bone, and the tip of the bone is star-shaped. This means that the user thinks that it may be sharp or not. In addition, selecting “AND” for the image group C2 in the upper area A1 and the image group C2 in the lower area A1 means that the user has bent the center of the bone and the tip of the bone is a star shape. This means that you are looking for a sharp image. On the other hand, selecting “OR” for the image groups C1, C2, and C4 in the upper area A1 on the upper side (further, the image groups C1 and C2 in the lower area A1 may be selected) It means you want to search for anything that looks like bone. In addition, the selection of the upper area A1 and the image group C2 in the lower area A1 by “AND” means that the user wants only an image in which the tip of the bone is pointed like a star. , Which means that attention is paid to the shape of the center of the bone (for example, the center of the bone is straight). In addition, selecting the upper area A1 and the image group C2 in the lower area A1 by “OR” means that the user points out that the tip of the bone is pointed like a star, but the center of the bone (For example, the center of the bone is straight).

  When the above step S6 ends and the user inputs his / her selection to the information terminal 3 via the selection screen W1 (step S7), the result of this selection is sent from the information terminal 3 via the network 6 to the selection receiving unit. It is transmitted to 21E (step S8).

  In subsequent step S9, the priority determination unit 21F determines the priority of the images included in the image groups I1, I2,... According to the user's selection in step S7. This priority is a reference for determining an image (hereinafter referred to as a presentation image) presented to the user as a result of the final search and an order in which the presentation image is presented.

  Specifically, first, the priority determination unit 21F selects the image groups I1 and I2 according to the classification pattern (hereinafter, selected classification pattern) or image group (hereinafter, selected image group) selected by the user in step S7. ,... Are presented or not presented for each image included in the images. Note that the image that has been labeled here becomes a presented image later, and the image that has been unpresented is excluded from the target presented to the user as a search result. Therefore, this labeling becomes a reference for determining a presentation image from the image groups I1, I2,. In other words, the priority determination unit 21F sets the priority of the image to which the presentation labeling is given higher than other images.

  When the classification pattern is selected by the user in step S7, the presentation labeling is the image group C1 (hereinafter referred to as a similar image group) having the highest similarity to the query image Q1 among the image groups defined by the selected classification pattern. For images belonging to. Note that the result of step S4 is used to determine the similarity. Here, when there are a plurality of selected classification patterns, the priority determination unit 21F specifies a similar image group for each selected classification pattern, and images belonging to an image group defined by a set operation of these similar image groups. Is given a label for presentation. More specifically, when “AND” is selected in step S7, the priority determination unit 21F selects images belonging to all of the plurality of similar image groups respectively corresponding to the plurality of selected classification patterns (that is, Labeling of presentation is given to images belonging to the logical product of these similar image groups. On the other hand, if “OR” is selected in step S7, the images belong to any of a plurality of similar image groups respectively corresponding to the plurality of selected classification patterns (that is, belong to the logical sum of these similar image groups). Presentation labeling is given to (image).

  On the other hand, when an image group has been selected by the user in step S7, presentation labeling is performed on images belonging to the selected image group. Here, when there are a plurality of selected image groups, the priority determination unit 21F assigns a presentation label to the images belonging to the image groups defined by the set operation of these selected image groups. More specifically, when “AND” is selected in step S7, the priority determination unit 21F includes images belonging to all of the plurality of selected image groups (that is, the logical product of these selected image groups). Presentation labeling is assigned to the image belonging to the image. On the other hand, when “OR” is selected in step S7, the labeling of the presentation is performed on the images belonging to any of the plurality of selected image groups (that is, the images belonging to the logical sum of these selected image groups). Is granted.

  If the classification group and the image group are selected by the user in step S7, the labeling of the presentation is performed on the group defined by the set operation of the similar image group and the selected image group. Is called. More specifically, when “AND” is selected in step S7, the priority determination unit 21F determines that images belonging to all of the above-described similar image group and selected image group (that is, these image groups). Presentation labels are given to images belonging to logical products). On the other hand, when “OR” is selected in step S7, the image is presented to an image belonging to either the above-described similar image group or the selected image group (that is, an image belonging to the logical sum of these image groups). Labeling is given.

  As described above, the presentation images are specified from the image groups I1, I2,..., And then the priority determination unit 21F determines the display order of the presentation images. Specifically, the priority determination unit 21F determines the priority of the presented image according to the similarity with the query image Q1 (the higher the similarity, the higher the priority). Note that the result of step S5 is used for the similarity determination. Thereby, the priority of the image contained in image group I1, I2, ... is determined per image. Here, if a classification pattern and / or image group corresponding to a plurality of feature descriptors is selected by the user in step S7, these plurality of feature descriptors (hereinafter referred to as selection descriptors). The plurality of similarity values exist for one presentation image. Therefore, in this case, the similarity cannot be simply compared when determining the priority of the presented image. Therefore, for example, it is conceivable to determine the overall similarity from a plurality of similarity values derived from a plurality of selection descriptors. A plurality of selection descriptors can be weighted and added together. In the latter case, the selection acceptance unit 21E causes the user to specify the weight of the selection descriptor on the selection screen W1 in accordance with the user selecting a specific classification pattern and / or a specific image group in step S7. Can do. Therefore, the user can specify a classification method that matches a user's intention by combining a plurality of feature descriptors, and thus can obtain a search result more in line with his / her intention.

  In the subsequent step S10, the second display control unit 21H displays the final search result as a search result screen W2 in which the presented images are arranged without duplication according to the priority determined in step S9 (see FIG. 8). ). At this time, the presentation image on the search result screen W2 is in a manner in which the priority level is known (when the presentation images are two-dimensionally arranged as shown in FIG. 8, from left to right, from top to bottom The lower the priority is, the lower the priority is, and the priority is displayed in a numerical form. Therefore, the search result screen W2 is a screen in which the presentation images searched according to the user's intention are arranged in the order according to the user's intention.

  The search result screen W2 is transmitted from the second display control unit 21H to the information terminal 3 via the network 6 and displayed on the display unit 31. Thus, the image search ends.

  After that, when the user selects a specific image on the search result screen W2, the second display control unit 21H enlarges and displays the selected image. In addition, when the classification pattern is selected in step S7, if the user desires further, among the image groups defined by the selected classification pattern, the similarity to the query image Q1 is second, third,. The same processing as that for the image group C1 is performed for the high image groups C2, C3,. In this case, on the search result screen W2, control is performed so that an image overlapping with an already displayed image is not displayed again.

<4. Application>
The image search system 1 can be used in various situations in which an image desired by a user is searched from an image group. For example, as a large-scale application, it can be used for an image search using an image group existing in the open world on the Internet as a search target. In this case, a collection of all kinds of devices that publish images on the Internet corresponds to the image server 2 described above. As a medium-scale application, it can be used for an image search (for example, a trademark search or a design search) that uses an image group in a specific commercial image database as a search target. Small-scale applications include individual devices within and / or external devices connected to individual computers (for example, a separate personal computer, USB memory, memory card, CD-ROM, external hard disk, digital The image group stored in the camera or the like can be used as a search target to perform image search from the personal computer. In this case, all kinds of devices connected to the information terminal 3 operated by the user and storing the image group to be searched correspond to the image server 2 described above.

<5. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, the following changes can be made.

<5-1>
In the above embodiment, an image similar to the entire query image is searched. However, an image whose whole is similar to the characteristic part of the query image, whose characteristic part is similar to the whole query image, or whose characteristic part is similar to the characteristic part of the query image may be searched. Further, at this time, the image may be searched while taking the inclination of the feature portion into consideration. Further, the extraction of the feature portion may be performed manually or automatically. Furthermore, on the search result screen, a feature portion similar to the query image may be highlighted in a manner such as being surrounded by a thick line, and an image that becomes the search result may be displayed.

The elemental technology for implementing this modification is detailed in the following documents, for example.
(1) Thi Thi Zin, Hiromitsu Hama, and Pyke Tin, "Object Image Retrieval in Deformable Shapes Using Morphological Operations Based on Dominant Color Regions", DICTA '08 Proceedings of the 2008 Digital Image Computing: Techniques and Applications, pp. 548- 555, IEEE Computer Society Washington, DC, USA, 2008

<5-2>
In the above embodiment, the classification pattern may not be selected on the selection screen W1. Alternatively, the image group may not be selected on the selection screen W1.

<5-3>
In the above embodiment, a logical sum (OR) and a logical product (AND) are exemplified as a set operation for combining a plurality of selection elements. However, for example, other set operations such as a logical difference and an exclusive logical sum may be used. it can. In any case, images that are outside the user's specified range will be excluded from the search results even if the similarity is high, and by allowing the user to select various set operation methods in this way, Can be freely reflected in the search results.

<5-4>
In the above embodiment, in step S9, the priority for selecting the presentation image is first determined, and then the priority for determining the display order of the presentation images is determined. Such a two-step step is not necessarily required to determine the above. For example, the following modes are also within the technical scope of the present invention.

  In this example, it is assumed that the user can select only the classification pattern in step S7. In this case as well, the user can select one or more feature descriptors in step S7, but when one feature descriptor is selected, the priority determination unit 21F selects the search target. For each image included in the image groups I1, I2,..., The similarity with the query image Q1 under the feature descriptor is determined. Then, the similarity is set as a priority, and a presentation image is determined according to a predetermined standard (for example, an upper predetermined number of images or an image with a similarity higher than a predetermined level), and the order of descending similarity is set as a display order. . On the other hand, even when a plurality of feature descriptors (selection descriptors) are selected in step S7, the priority determination unit 21F displays each image included in the image groups I1, I2,. For the query image Q1. However, this similarity is an overall similarity obtained by combining a plurality of similarities under a plurality of selection descriptors. In determining the overall similarity, a plurality of similarities under a plurality of selection descriptors may be simply added, or a plurality of selection descriptors may be added with a weight added. Good. In the latter case, the weight of the selection descriptor can be specified by the user on the selection screen W1 by the selection receiving unit 21E in accordance with the user selecting a plurality of classification patterns in step S7. Then, the overall similarity is set as a priority, and a presentation image is determined according to a predetermined standard (for example, an upper predetermined number of images or an image having a similarity equal to or higher than a predetermined level). The highest order is the display order. Therefore, the user can specify a classification method that matches a user's intention by combining a plurality of feature descriptors, and thus can obtain a search result more in line with his / her intention.

<5-5>
In the above embodiment, in step S9, all images belonging to a similar image group, a selected image group, or an image group defined by a set operation of these image groups are set as presentation images. It may be a presentation image. As a method of selecting some of the images, for example, the similarity with the query image Q1 is set as a priority, and a presentation image is determined according to a predetermined standard (for example, an upper predetermined number of images or an image with a predetermined similarity or higher). Can).

1 Image search system (image search device)
2 Image server 2A Image search program 3 Information terminal 21B Classification unit 21C Query reception unit 21E Selection reception unit 21F Priority determination unit 21G First display control unit 21H Second display control unit C1, C2 ... Image groups D1, D2, ... Feature descriptors I1, I2, ... Image group Q1 Query image

Claims (11)

A classification unit that classifies the same image group with a plurality of classification patterns according to a plurality of classification conditions;
A first display control unit for displaying a result of classification in the plurality of classification patterns;
After displaying the classification result, the user selects a specific classification pattern and / or a specific image group from the plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns. A selection reception unit for receiving,
A priority determination unit that determines a priority of an image included in the image group according to the specific classification pattern and / or the specific image group;
A second display control unit configured to display an image included in the image group according to the priority.
Image search device. A query receiving unit for receiving a query image designation from the user;
The first display control unit preferentially displays an image belonging to the image group having a high similarity to the query image from the image group for each classification pattern, thereby obtaining the classification result. indicate,
The image search device according to claim 1. The priority determination unit has a high similarity to the query image in the image group defined by the specific classification pattern when the selection reception unit receives selection of the specific classification pattern from a user. Setting the priority of images belonging to similar image groups high;
The image search device according to claim 2. The selection receiving unit receives a plurality of selections of the specific classification pattern;
The priority determination unit specifies the similar image group for each of the specific classification patterns, and belongs to a group defined by a set operation of the plurality of similar image groups respectively corresponding to the plurality of specific classification patterns. Set a higher priority for the image,
The image search device according to claim 3. The priority determination unit sets the priority of images belonging to the specific image group high when the selection reception unit receives a selection of the specific image group from a user.
The image search device according to claim 1. The selection receiving unit receives a plurality of selections of the specific image group,
The priority determination unit sets the priority of images belonging to a group defined by a set operation of the plurality of specific image groups to be high;
The image search apparatus according to claim 5. The selection receiving unit receives selection of the specific classification pattern and the specific image group;
The priority determination unit specifies a similar image group having a high similarity to the query image among the image groups defined by the specific classification pattern, and determines the similarity between the similar image group and the specific image group. Setting the priority of the images belonging to the group defined by the set operation high;
The image search device according to claim 2. The selection accepting unit accepts selection of the classification condition and accepts designation of the weight of the classification condition by accepting selection of the specific classification pattern and / or the specific image group from a user,
When the selection receiving unit receives a plurality of selections of the specific classification condition from a user, the priority determination unit applies the weight to the image group under the specific classification conditions weighted according to the weight. Determining the similarity between the included image and the query image, and determining the priority according to the similarity;
The image search device according to claim 2. The classification condition is defined by a feature descriptor that is one feature or a combination of a plurality of features.
The image search device according to claim 1. Classifying the same image group with a plurality of classification patterns according to a plurality of classification conditions;
Displaying the result of classification in the plurality of classification patterns;
After displaying the classification result, the user selects a specific classification pattern and / or a specific image group from the plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns. Accepting steps,
Determining a priority of an image included in the image group according to the specific classification pattern and / or the specific image group;
Displaying images included in the image group according to the priority,
Image search method. Classifying the same image group with a plurality of classification patterns according to a plurality of classification conditions;
Displaying the result of classification in the plurality of classification patterns;
After displaying the classification result, the user selects a specific classification pattern and / or a specific image group from the plurality of classification patterns and / or a plurality of image groups defined by the plurality of classification patterns. Accepting steps,
Determining a priority of an image included in the image group according to the specific classification pattern and / or the specific image group;
Causing the computer to execute a step of displaying an image included in the image group according to the priority.
Image search program.