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Thursday, 22 June 2017
Multimedia Database Management System (MMDB)
Multimedia Database Management System (MMDBMS)
What is Multimedia Database(MMDB)?
• Multimedia database is a collection of related multimedia data such as TEXT, GRAPHIC, VIDEO, ANIMATION.
• MMDB stores data in the form of, text, images, graphic, animation, audio and video.
• A multimedia database is a database that include one or more primary media file types such as .txt (documents), .jpg (images), .swf (videos), .mp3 (audio), etc
Evolution of MMDB
Since existing relational and OO databases comprise(satisfy) the basic requirements of any database, but to store multimedia data -MMDB’s were evolved, that includes
• Long bit, byte strings
• BLOBS
• paths or references of images where the actual image stored elsewhere, such as on an optical storage subsystem.
• Content retrieval capabilities.
What Is Multimedia Database Management System (MMDBMS) ?
It is a framework that manages different types of data potentially represented in a wide diversity of format on a wide array of media sources.
It provides support for multimedia data types
Provide facilitate for
1) Creation
2) Storage
3) Access
4) Query
5) Control of a multimedia database
Contents of MMDB
• Media data - actual data representing images, audio, video that are captured, digitized, processes, compressed and stored.
• Media format data - contains format information of the media data after it goes through the acquisition, processing, and encoding phases.For instance, this consists of information such as the sampling rate, resolution, frame rate, encoding scheme etc.
• Media keyword data - contains the keyword descriptions, For example, for a video, this might include the date, time, and place of recording , the person who recorded, the scene that is recorded, etc .This is also called as content descriptive data.
• Media feature data - contains the features derived from the media data. For example, contain information about the distribution of colors, the kinds of textures and the different shapes present in an image. This is also referred to as content dependent data.
The last three types are called meta data as they describe several different aspects of the media data.
The media keyword data and media feature data are used as indices for searching purpose.
The media format data is used to present the retrieved information.
• Audio: aural recordings in a string of bits in digitized form
Data types are categorized into 3 classes
• Static media
time-independent
image and graphic object
• Dynamic media
time-dependent
Audio, video and animation
• Dimensional media
3D game and Computer Aided Drafting (CAD) programs.
Characteristics of MMDM
• Corresponding Storage Media, Data must be stored & managed according to their specific characteristics of the storage media
• Descriptive Search Methods
Query must be descriptive & content oriented
• View Specific & Simultaneous Data Access
Same data can be accessed through different queries by different applications
• Management of Large Amounts of data
• Data transfer of real time activity gets higher priority than other database activities
• Large transactions must be done in a reliable fashion, since it take long time.
Requirements of Multimedia databases
• Integration
Data items do not need to be duplicated for different programs invocations
• Data independence
Separate the database and the management from the application programs
• Concurrency control
Allows concurrent transactions
• Persistence
Data objects can be saved and re-used by different transactions and program invocations
• Privacy
Access and authorization control
• Integrity control
Ensures database consistency between transactions
• Recovery
Failures of transactions should not affect the persistent data storage
• Query support
Allows easy querying of multimedia data
Design goal of MMDB
• Manage different types of input, output, and storage devices
• Handle a variety of data compression and storage formats
• Support different computing platforms and operating systems
• Integrate different data model.-(R database , OO database)
• Offer a variety of user-friendly query systems suited to different kinds of media.
• Handle different kinds of indices • Provide transparent view of geographically distributed data
• Synchronize different media types while presenting to user
Data Structures
• Raw Data - Uncompressed Image
• Registering Data - Size & coding details of raw data
• Descriptive Data - Textual numerical annotations Media Raw Registering Descriptive Text
Characters Coding scheme (ASCII), length / end symbol Key words, information for structuring Images Pixels Height/ Width of picture, Mode of Compression, if JPEG, tables for quantization purpose Pic.Date = 21/04/07 Pic.Reason = Birthday Etc Video Pixels Frames/second, coding details, frame types… Scene description Audio Sample sequence Audio coding (PCM,…) , resolution of samples Content of audio passages in short form
MM Database Architecture
Querying MM data
• A DBMS permits a user to search the database by content e.g. give the name of the student with roll number 123456 We would like to do the same with multimedia data
• e.g. Consider a police investigation of a murder case. give the picture of a this person or audio files to multimedia data library( contain CCTV footage, authorized telephone wiretaps, document data ,bank transition.)
• With standard data this is easy – numeric and string operators are well understood With multimedia data this is more difficult and requires some method of identifying contents of which there are two kinds:
1) Automatic identification an algorithm takes the data and returns a measure which can be compared – e.g. of blackness
2) manual identification a person examines the data and catalogues it – e.g. in a table of pictures, there is a column for the picture and another for the painter
Housing Multimedia Data
There are three kinds of DBMS that might be used for housing multimedia data.
1) Relational DBMS store everything as First Normal Form tables
2) Object-oriented DBMS store everything as classes of objects
3) Object-relational DBMS are fundamentally relations but are not First Normal Form
Relational DBMS
Oracle support three large object types:
• BLOB(Binary Large Objects – BLOB)
The BLOB domain type stores unstructured binary data in the database. BLOBs can store up to four gigabytes of binary data.
• CLOB(Character Large Object)
CLOB data type stores large amounts of character data, up to 4 GB in size. The CLOB data type is similar to a BLOB, but includes character encoding, which defines a character set and the way each character is represented. BLOB data, on the other hand, consists of unformatted binary data.
• NCLOB(National Character Large Object)
It is an Oracle data type that can hold up to 4 GB of fixed-width and varying width multi-byte national character set data . It's similar to a CLOB, but characters are from the national character set.
Note : Relational databases efficient for numeric and textual data store, but do not conveniently support content- based searches for multimedia content.
Storing in Database
Oracle InterMedia
Example:
create table image_blob_table
(
id number primary key,
image_blob BLOB
);
insert into image_blob_table
(id,image_blob)
values (1, “Path of image”) ;
Object-oriented DBMS
• Jasmine is an Object-Oriented database that stores the data in form of classes and objects
• It comes with a number of built in classes include four multimedia classes:
- Picture
- Image
- Video
- Audio
• These come with manipulation and compression facilities.
• They also have been made to fit well with Java Media Framework
Object-relational DBMS
• The BFILE data type in Oracle provides access to BLOB files of up to 4 GB that are stored in file systems outside an Oracle database.
• A BFILE is a data type used to store a locator (link) to an external binary file (file stored outside of the database)
• The BFILE data type allows read-only support of large binary files; you cannot modify a file through Oracle. Oracle provides APIs to access file data.
Example:
Create or Replace procedure
insert_image_file
(
p_id NUMBER,
p_image_name IN VARCHAR2
) IS
src_file BFILE; dst_file BLOB;
BEGIN src_file := BFILENAME ('image_DIR', p_image_name);
INSERT INTO temp_image (ID, image_name, image )
VALUES (p_id, p_image_name, EMPTY_BLOB () )
RETURNING image INTO dst_file;
END insert_image_file;
Execute:
EXECUTE insert_image_file(1,'test_image.jpg');
Performance Issues MMDBMSs
provides good performance for real-time querying and updating. Some of the features that influence this are:
• Indexing - most DBs use single key access (B-trees) whereas, MM have multidimensional indexes with two dimensional objects have X and Y co-ordinates (R-trees)
• Content-Retrieval Indexing - special indexes are required for this. For example, the index for a video could contain the frame number of the start of each clip or scene.
• Query Optimization - MMDBs are large and manage many complex object providing query optimization
Databases requires
• well structured data organisation
• efficient storage of large amounts of data
• Querying • Fast retrieval of request
• transactional support for concurrent users
Issues and challenges
• Multimedia data consists of a variety of media formats or file representations including TIFF, BMP, PPT, FPX, MPEG, AVI, MID, WAV, DOC, GIF,PNG,TEC
• Because of restrictions on the conversion from one format to the other, the use of the data in a specific format has been limited as well.
• Usually, the data size of multimedia is large such as video; therefore, multimedia data often require a large storage.
• Multimedia database consume a lot of processing time, as well as bandwidth.
• multimedia data structures takes much time in retrieval than standard database structures
• multimedia data structures do not easily lend themselves to content-based searching
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