Content-Based Retrieval of Image

ü  System retrieves images that best match the description.

ü  Image content can be defined at different levels of abstraction

Lowest level

o   Image is a collection of pixels.

o   Rarely used.

The raw data can be processed to produce numeric descriptors capturing specific visual characteristics called features.

–     Color,

–     Texture, and

–     Shape

Features can be extracted from entire images describing global visual characteristics

                  Portions of images describing local characteristics

Highest Level

–     Images are often accompanied by metadata.

–     Metadata may contain information that cannot be obtained directly from the image, as well as an actual description of the image content.

–     Medical images.

Radiological report

Multidimensional Indexing

ü  Multidimensional descriptors

–     colour or

–     texture

ü  Search task can be made significantly more efficient by relying on multidimensional indexing structures.

ü  RDBMS should not support Multidimensional indexes.

Image Element representation = {Element name, Element colour, Element shape, Element attribute}.

By using this the images are retrieved

Image Retrieval

ü  Image retrieval in the Image database system

  1.“direct query”

- the user specifies the query by directly picking colour from the colour palette

  2.“image query”

- the user asks for images similar to a given image or containing given image.

              3.“textual query”

- the user specifies a textual description of the search image.

              4.combination of all of the above.

Creating the Image Database

ü  Creating image database in MySQL

–     Create a MySQL database called Database_Image.

–     Create a table called images with two rows

•      Imageid

•      Description.

–     Query

CREATE TABLE  Images

( imgid          INT                 NOT NULL AUTO_INCREMENT ,

  description LONGTEXT   NOT NULL ,

  PRIMARY KEY ( imgid ) );