Oracle8i Visual Information Retrieval User's Guide and Reference
Release 8.1.5






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See object type.

aspect ratio

Proportions of height versus width.


A large object whose value is composed of binary data, and is stored outside of the database in an operating system file. The file itself is not stored in the database, but a pointer to the file is stored in the database. Because they are outside of the database, BFILEs are read-only.

binary large object



The science of using personal characteristics to verify identity. This method uses a non-intrusive test, such as face or fingerprint recognition, rather than an intrusive test such as DNA or blood type analysis.


Binary large object. Large objects are stored in the database tablespace in a way that optimizes space and provides efficient access. Only a pointer to the object is actually stored in the row.

content format

A description of the image data, such as the pixel or color format.


Selecting the portion of an image within a specified rectangle and removing everything outside of that rectangle. See also cutting.


Selecting the portion of an image within a specified rectangle to create a subimage. If the subimage is copied to a new image, the effect is a cut. If the subimage replaces the original, the effect is a crop. Use the Process( ) or ProcessCopy( ) procedures to cut or crop an image.

data service

The mechanism by which clients, application-specific servers, and database servers can be easily and reliably extended.

default constructor

The type of constructor in an Oracle Call Interface (OCI) call that creates an empty instance of the constructor.


A measure of how similar two images are. When two images are compared, a distance value for visual attribute and an overall distance value (weighted sum of the attribute distances) are calculated. The distance for each visual attribute can range from 0 (no difference) to 100 (maximum possible difference). Thus, the more similar two images are with respect to a visual attribute, the smaller the distance will be between their scores for that attribute.

file format

The file format of the image data, such as BMPF or GIFF.

foreign images

An image whose type is not natively supported by Visual Information Retrieval. Instead, the product provides direct acces to the pixel data.

global color

The visual attribute that represents the distribution of colors within the entire image. This distribution includes the amounts of each color, but not the locations of color.


Interface Definition Language.


A graphic picture. The source could be a photograph, drawing, or generated image.

image processing

A change to the properties of an image, such as through scaling, rotation, or compression.

local color

The visual attribute that represents color distributions and where they occur in an image, such as the fact that an RGB vector for sky blue occurs in the upper half of an image.

lossless compression

A means for reducing the storage space required for an image. The decompressed image is bit-for-bit identical to the original.

lossy compression

A means for reducing the storage space required for an image. The decompressed image has less resolution than the original, although this might not be noticeable to the naked eye.


Multi-purpose Internet Mail Extensions. MIME is an Internet specification describing file types. Servers and browsers read the MIME type in the file header and decide what to do with the file, such as displaying it with a viewer or playing it as an audio file.

Network Computing Architecture

A fully integrated design integrating text, spatial, and image data. The architecture supports the design, development, installation, and integration of manageable components across entire organizations.

object relational database

A database having both object-oriented and relational characteristics. Objects can be defined and stored, and then retrieved using standard relational methods.

object type

A data type that encapsulates attributes of the data and methods (functions and procedures) for operating on the data.

An object data type is sometimes referred to as an abstract data type (ADT).


Oracle Call Interface.

raw pixel format

An uncompressed image format with a simple, fixed-size header.


A change to the proportions of an image in one or both dimensions. To enlarge an image, scale by a factor greater than one. To shrink an image, scale by a factor between zero and one. Use the Process( ) or ProcessCopy( ) procedures to scale an image.


The visual attribute that represents the shapes that appear in the image, as determined by shape-characterization techniques, rather than by local shape-segmentation methods (which are affected by problems due to lighting effects and occlusion).


The visual attribute that represents the low-level patterns and textures within the image, such as graininess or smoothness. Unlike structure, texture is very sensitive to high-frequency features in the image.


The numeric value used in a comparison to determine whether or not two images match. If the weighted sum of the distances for the visual attributes is less than or equal to the threshold, the images match; if the weighted sum is greater than the threshold, the images do not match.


A numeric value assigned to a visual attribute to determine how important that attribute is in determining whether or not two images being compared match. Each weight value can range from 0.0 (no importance) to 1.0 (highest importance), and reflects how sensitive the matching process should be to the degree of similarity or dissimilarity between two images with respect to that attribute.


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