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Image, Audio, and Video Extenders Administration and Programming


Glossary

administrative support table
One of the tables that are used by a DB2 extender to process user requests on image, audio, and video objects. Some administrative support tables identify user tables and columns that are enabled for an extender. Other administrative support tables contain attribute information about objects in enabled columns. Also called a metadata table.

analyze
To calculate numeric values for the features of an image and add the values to a QBIC catalog.

API
See application programming interface.

application programming interface (API)

(1) A functional interface supplied by the operating system or by a separately orderable licensed program. An API allows an application program that is written in a high-level language to use specific data or functions of the operating system or the licensed programs.

(2) In DB2, a function within the interface, for example, the get error message API.

(3) The DB2 extenders provide APIs for requesting user-defined functions, administrative operations, display operations, and video scene change detection.

audio
Pertaining to the portion of recorded information that can be heard.

average color
A measurement of color that is computed as an average of the color values that are contained in the pixels of an image.

audio clip
A section of recorded audio material.

binary large object (BLOB)
A binary string whose length can be up to 2 GB. Image, audio, and video objects are stored in a DB2 database as BLOBs.

character large object (CLOB)
A character string of single-byte characters, where the string can be up to 2 GB. CLOBs have an associated code page. Text objects that contain single-byte characters are stored in a DB2 database as CLOBs.

coarseness
An attribute of texture that measures the scale of the texture (pebbles versus boulders).

contrast
An attribute of texture that refers to the vividness of the pattern, and is a function of the variance of a grey-level histogram.

database partition
A part of the database that consists of its own user data, indexes, configuration files, and transaction logs. Sometimes called a node or database node.

database partition server
Manages a database partition. A database partition server is composed of a database manager and the collection of data and system resources that it manages. Typically, one database partition server is assigned to each machine.

DB2 extender
One of a group of programs that you use store and retrieve data types beyond the traditional numeric and character data, such as image, audio, and video data, and complex documents.

directionality
An attribute of texture that describes whether the image has a favored direction (like grass) or is like a smooth object (like glass).

dissolve
To decrease the strength of a signal for a video frame as the strength of the signal for the next video frame increases.

distinct type
See user-defined type.

double-byte character large object (DBCLOB)
A character string of double-byte characters, or a combination of single-byte and double-byte characters, where the string can be up to 2 GB. DBCLOBs have an associated code page. Text objects that include double-byte characters are stored in a DB2 database as DBCLOBs.

environment variable
A variable used to describe the operating environment for the DB2 extenders and to provide defaults for values for the environment.

extender
See DB2 extender.

feature
A visual attribute of an image, such as average color.

file reference variable
A programming variable that is useful for moving a LOB to and from a file on a client workstation.

gigabyte (GB)
One billion

handle
A character string that is created by an extender that is used to represent an image, audio, or video object in a table. A handle is stored for an object in a user table and in administrative support tables. In this way, an extender can link the handle that is stored in a user table with information about the object that is stored in the administrative support tables.

histogram color
A measurement of the distinct colors in an image. Data for each color is stored separately in a QBIC catalog.

host variable
A variable in an application program that can be referred to in embedded SQL statements. Host variables are the primary mechanism for transmitting data between a database and application program work areas.

image
An electronic representation of a picture.

index file
A file that contains indexing information used by the Video Extender to find a shot or an individual frame in a video clip.

instance
A logical DB2 extender server environment. You can have several instances of DB2 extenders server on the same workstation, but only one instance for each DB2 instance. You can use these instances to:

Separate the development environment from the production environment

Restrict sensitive information to a particular group of people.

kilobyte (KB)
One thousand

large object (LOB)
A sequence of bytes, where the length can be up to 2 GB. A LOB can be of three types: binary large object (BLOB), character large object (CLOB), or double-byte character large object (DBCLOB).

LOB locator
A small (4-byte) value stored in a host variable that can be used in a program to refer to a much larger LOB in a DB2 database. Using a LOB locator, a user can manipulate the LOB as if it was stored in a regular host variable, and without the need to transport the LOB between the application on the client machine and the database server.

megabyte (MB)
One million

metadata table
See administrative support table.

multipartition nodegroup
A nodegroup that contains more than one database partition server.

node
In database partitioning, synonymous with database partition.

nodegroup
A named group of one or more database partitions.

object
In object-oriented programming, an abstraction consisting of data and the operations associated with that data.

object orientation
A programming approach in which anything, real or abstract, can be represented in an application as an object that comprises a set of operations and data values. For example, a document can be represented by a document object that comprises document data and operations that can be performed on the document, such as filing, sending, and printing. A video clip can be represented by a video object that comprises video data and operations such as playing the video clip or finding a specific video frame.

partitioned database
A database with two or more database partitions. Data in user tables can be located in one or more database partitions. When a table is on multiple partitions, some of its rows are stored in one partition and others are stored in other partitions.

pixel
The smallest element of an image that a screen can display.

positional color
The average color value of the pixels in a specified area of an image.

Query by Image Content (QBIC)
A capability that is provided by the Image Extender that allows users to search images by their visual characteristics such as average color and texture.

QBIC catalog
A repository that holds data about the visual features of images.

query object
An object that specifies the features, feature, values, and feature weights for a QBIC query. The object can be named and saved for subsequent use in a QBIC query. Contrast with query string

query string
A character string that specifies the features, feature, values, and feature weights for a QBIC query. The query string can be entered in a query from the DB2 command line. Contrast with query object

scaling
Adding nodes to a database to increase storage space and performance.

scene change
A point in a video clip where there is a significant difference between two successive frames. This happens, for example, when a camera changes its point of view while recording a video.

score
A calculated value that reflects how similar the feature values are to those that are specified in a query by image content. The higher the number, the closer the match. The score is used to sort the results of a query by image content.

shot
The frames between two scene changes.

shot catalog
A database table or file that is used to store data about shots, such as the starting and ending frame number for a shot, in a video clip. A user can access a view of the table through an SQL query, or access the data in the file.

storyboard
A visual summary of a video. The Video Extender includes features that can be used to identify and store video frames that are representative of the shots in a video. These representative frames can be used in building a storyboard.

terabyte
A trillion (1012) bytes. Ten to the twelfth power bytes. When referring to memory capacity, 1 099 511 627 776 bytes.

texture
One of the features that can be used in a query by image content. It refers to the coarseness, contrast, or directionality of an image.

thumbnail
A miniature image.

trigger
The definition of a set of actions to be taken when a table is changed. Triggers can be used to perform actions such as validating input data, automatically generating a value for a newly inserted row, reading from other tables for cross-referencing purposes, or writing to other tables for auditing purposes. Triggers are often used for integrity checking or to enforce business rules.

UDF
See user-defined function.

UDT
See user-defined type.

user-defined function (UDF)
A function that is defined by a user to DB2. Once defined, the function can be used in SQL queries. and video objects. For example, UDFs can be created to get the compression format of a video or return the sampling rate of an audio. This provides a way of defining the behavior of objects of a particular type.

user-defined type (UDT)
A data type that is defined by a user to DB2. UDTs are used to differentiate one LOB from another. For example, one UDT can be created for image objects and another for audio objects. Though stored as BLOBs, the image and audio objects are treated as types distinct from BLOBs and distinct from each other.

video
Pertaining to the portion of recorded information that can be seen.

video clip
A section of filmed or videotaped material.

video index
A file that the Video Extender uses to find a specific shot or frame in a video clip.


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