JPH0916618A - Data base system - Google Patents

Abstract

PURPOSE: To quickly retrieve required multimedia information by preparing an index for applying a pointer to multimedia information by using an attribute value indicating the attribute of unit data and the frequency of the unit data having the attribute value as keys. CONSTITUTION: In the case of retrieving a data base 10 storing picture data 12, 13 as multimedia information, a color index 14 for applying a pointer to the multimedia information is prepared by using an attribute value indicating the attribute of unit data such as a color, a sound and movement and the frequency of the unit data having the attribute value as keys, the frequencies of respective color components are found out from a provision picture 11 provided by a user and compared with each other and a color component to be selected is displayed on a color pallet. Consequently required multimedia information can quickly be retrieved by giving retrieving keys utilizing the features of the multimedia information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia information database system.

[0002]

2. Description of the Related Art FIG. 5 briefly shows the structure of a database system. As shown, a query 50 from a user is first translated into a database command by query processor 51. Then, it is converted into a file operation by the database management 52. The file management 53 has information on the storage structure of the database 55 on the secondary storage, and accesses the page on the secondary storage based on this information. The index 54 is provided to speed up the search process, and adds auxiliary access information to the data accumulated in the database 55.

When searching a database using an index, the same method as when using a book index can be used. That is, instead of scanning every page of a book, it first looks at the index. If you find the word you are looking for in the index,
I know which page to read. In the database system, auxiliary access information called an index is represented by a set of (x, p). Let p be the pointer to the data with the key x in the database. With this index structure, it is possible to know where the data having a certain key is in the database, and therefore, it is not necessary to perform random search to read unnecessary data from the database and repeat trial and error.

[0004]

Image, video, and audio information have been digitized, and these have been handled as multimedia information integrated with conventional text and numerical data. Even in database systems, there is an increasing need to manage such multimedia information.
However, the index (x, p) used in the conventional database system cannot handle inquiries about information that does not include words, such as images, or information that cannot be expressed in clear words.

For example, a still image having color information can be digitized, and the data can be named and registered in a database. Then, the still image can be searched from the database using the name of the data as a keyword. However, it is difficult to perform a search based on a sensory impression such as the color tone of a still image, and the conventional keywords are obviously insufficient. Even if the same design is used, different colors may give a completely different impression, so it is very significant to realize a search with this difference.

In addition to the color information, the texture of the image data is also a major element characterizing the image. It is difficult to express the difference in texture with keywords,
After all, it is desired to realize a search that exemplifies an actual texture.

There are many inconveniences in searching the moving image database. As an example, consider finding a scene that includes a specific motion. At present, it is necessary to search for a motion by expressing it with a keyword, but it is difficult to express the keyword itself for a complicated motion over a certain level. However, for complicated movements, it is natural to write down the locus of the movements and make an inquiry.

[0008] Regarding voices, it may be necessary to recognize or identify different voice information depending on differences in pitch, height, etc. of utterances. Since it is difficult to associate such information with keywords, a system that can use voice data in actual search is required.

In view of the above points, the present invention improves a method of searching data stored in a database by a keyword, and provides a search key that makes the best use of the characteristics of multimedia information to obtain desired multimedia information. It is an object of the present invention to provide a database system capable of high-speed search.

[0010]

According to the invention, the above-mentioned object is achieved by the means described in the claims.

That is, according to the invention of claim 1, in a database accumulating multimedia information formed of a set of unit data, an attribute value indicating an attribute of the unit data,
This is a database system that provides an index that gives a pointer to multimedia information using the frequency of unit data having that value as a key.

Further, the invention of claim 2 is a database system having means for obtaining a pointer to multimedia information from a key close to a key inquired by the index.

The invention according to claim 3 is a database system for searching multimedia information by combining a search by a keyword added to multimedia information and a search by the index.

Further, the invention of claim 4 is a database system in which the attribute value has one or a plurality of components, and the index gives a pointer to multimedia information using the frequency for an arbitrary number of components as a key. Yes,
According to a fifth aspect of the present invention, there is provided a database system, wherein the attribute value has one or a plurality of components representing a specific color, and a means for displaying the color in a color palette.

[0015]

In the database system of the present invention, colors, sounds, movements, etc. are expressed as attribute values according to the characteristics of multimedia information. Then, the frequency for the attribute value is calculated. The user who makes the inquiry requests the attribute value and the frequency. When the attribute value and the frequency are obtained by a predetermined method, the index is referred to and appropriate multimedia information is output.

[0016]

[Example] For an attribute of multimedia information, an attribute value is determined if an attribute space can be created. There are multiple types of multimedia information that can create an attribute space, but in the following, color still image data will be described. It goes without saying that similar processing can be performed on other multimedia information by using the attribute space.

In order to handle image information efficiently, it is necessary for the database system to be appropriately structured and managed so that it can be searched at high speed. It is considered appropriate to store color information as an index in order to realize such high-speed retrieval.

RG is used as a commonly used color space.
B, YUV, YCbCr, etc. are known, and an index is created using these color spaces as an attribute space. For a block obtained by dividing each image into m, a set of each color and its frequency, which is a component of an attribute value, is a key x, and a pointer to image data having the key x is p. Index {(x1, p
k), ..., (xn, pk)} are created. The color component values can also be quantized with an appropriate step size.

FIG. 2 is an explanatory diagram visualizing the contents of the index according to the present invention. In FIG. 1, the attribute values are the components [color a], [color b], [color c],
Includes [color d] and the like. These are, for example, RG
It can be positioned in the color space of B, and [color a] is [RaGaBa] and [color b] is [RbGbBb].
[Color c] is [RcGcBc] and [Color d] is [Rd
GdBd].

Here, the index for [data 02] of the multimedia information indexed by [pointer 02] is {((RaGaBa, 50), pointer 02),
((RbGbBb, 50), pointer 02), ((RcGcB
c, 0), pointer 02), ..., ((RnGnBn,
0), pointer 02)}.

FIG. 1 is a diagram showing an example of a search mode based on color information. When searching the database 10 that stores the image data 12 and 13, the image 11 presented by the user can be used as a kind of key. The frequency for each color component is obtained from the presented image 11 by the above-described method and compared with the color index 14. At this time, the number of search keys to be compared (search range) adaptively changes according to the required accuracy of the search result.

Even if the image data is searched using the color index 14 as described above, there is a case where a key that is completely identical to the key obtained from the presentation image 11 cannot be found.
In such a case, it is possible to consider that the image data having the most approximate frequency or the image data included within a predetermined threshold value are matched. This processing may be performed on all the divided blocks, and a logical product obtained by combining a plurality of keys can be used as the final search result.

FIG. 3 is an explanatory diagram of the search space. This search space can be generated from the color index. In the figure, since the color space uses YUV, the color information is represented by U and V components. Each color component is taken very coarsely for ease of explanation and quantized into four levels. Further, for simplification, the number of divisions of the image data is set to one and the entire image is regarded as one block. The four image data p1, p2, p3, p stored in the database
For 4, the frequency of the color component will be obtained.

In the search space shown, a frequency axis is added to the color space, but the attribute value is shown on the UV plane, which is the color space, and the frequency is expressed according to the height. When the frequency for each color component is obtained, it is possible to search using 16 types of color components, but it is not necessary to use all color components, and it is also possible to search using only some color components.

FIG. 4 is an explanatory diagram of the search method. Here, a multidimensional index is created, the number of search keys corresponding to the search range is set to 3, and three color components are selected. Now, the value and frequency of the color component are obtained from the image presented by the user, and a match is searched for in the search space. If there is no match, the ID of the image within the predetermined threshold value is obtained for each of the three keys. In the case of FIG. 4, it corresponds to that included in the sphere of radius α.

Finally, the logical product of the three types of candidates is taken and the result is obtained. In this example, the image data p1 is presented to the user as the closest one. When divided into a plurality of blocks, if the logical product of all blocks is taken, the final result that meets the detailed conditions can be obtained.

In addition to the method of searching the image data from the presented image, there is a method of directly inputting the color component and the frequency to search the image data. In this case, when the color component is displayed on the color palette, the color component to be selected can be visually confirmed. You can search the database by clicking a specific color component displayed on the color palette with the pointing device and keying in the frequency. As a method of specifying the frequency, not only the% value,
It is possible to specify "≠ 0" or "less than 5%",
It is also possible to specify that the frequency ratio of color a and color b is 1: 1.

Further, the color index described in this embodiment and the keyword index used in the conventional database system can be used to respond to a user's inquiry, and a search combining these indexes can be performed.

For example, in the case of an image database for paintings, data such as the museum of paintings, the age of the painting, the name of the image, etc. can be treated as a conventional keyword index. By using this together with the color index, it is possible to realize an advanced search that cannot be done with keywords alone. In fact, even if most of the painting data primarily searched by the conventional keywords are based on blue colors, using the index according to the present invention,
Effective secondary search can be performed. That is, in the secondary search utilizing the present invention, if blue, ultramarine, navy blue, light blue or the like is selected as the color component to be selected, it is easy to identify the painting data having an approximate color arrangement.

[0030]

As described above, according to the present invention,
It is possible to effectively realize a search for multimedia information that cannot be expressed only by keywords in words. So, for example,
If you make a database of clothing images that are sold online, you will be able to instantly search for clothes of your favorite color, and by collecting and searching karaoke data, you can find songs that match your voice quality. Some songs could be presented quickly.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a search mode based on color information.

FIG. 2 is an explanatory diagram visualizing the contents of an index according to the present invention.

FIG. 3 is an explanatory diagram of a search space.

FIG. 4 is an explanatory diagram of a search method.

FIG. 5 is a diagram simply showing the structure of a database system.

[Explanation of symbols]

 10,55 Database 11 Presented image 12,13 Image data 14,54 Index 50 User inquiry 51 Inquiry processor 52 Database management 53 File management

Claims (5)

[Claims] 1. A pointer to multimedia information in a database, which stores multimedia information formed of a set of unit data, using an attribute value indicating an attribute of the unit data and a frequency of the unit data having the value as keys. A database system characterized by providing an index for giving. 2. The database system according to claim 1, further comprising means for obtaining a pointer to the multimedia information from a key that is similar to the inquired key by the index. 3. The database system according to claim 1, wherein the multimedia information is searched by combining a search by a keyword added to the multimedia information and a search by the index. 4. The database system according to claim 1, wherein the attribute value has one or a plurality of components, and the index gives a pointer to multimedia information using a frequency for an arbitrary number of components as a key. 5. The database system according to claim 1, wherein the attribute value has one or a plurality of components representing a specific color, and means for displaying the color in a color palette.