CBIR or Content Based Image Retrieval is the retrieval of images based on visual features such as colour, texture and shape. Reasons for the development of CBIR systems is that in many large image databases, traditional methods of image indexing have proven to be insufficient, laborious, and extremely time consuming. These old methods of image indexing, ranging from storing an image.
In the database and associating it with a keyword or number, to associate it with a categorized description, has become obsolete. In CBIR, each image that is stored in the database has its features extracted and compared to the features of the query.
Feature (content) extraction is the basis of content based Image Retrieval. In broad sense, features may include both text based features (keywords, annotations, etc) and visual features (colour, texture, shape, faces, etc). Within the visual feature scope, the features can be further classified as general features and domain specific features. The former include colour, texture and shape features while the latter is application dependent and may include, for example, human faces and finger prints.