A HAND BOOK ON IMAGE RETRIEVING

Image retrieval is one of the main topics in the field of computer vision and pattern recognition. In the early 1990s, researchers have built many image retrieval systems, such as QIBC, MARS, FIDS and so on. They are different from the traditional image retrieval systems. These systems are based on image features such as color, texture, shape of objects and so on. Nowadays, the main research work of image retrieval consists of feature extracting techniques, image similarly match and image retrieval methods. Many researchers have put forward various algorithms to extract color, texture and shape features. Color is the most dominant and distinguishing visual feature. Color histogram-based techniques re-main popular due to their simplicity, but it lacks spatial information. Several color descriptors try to incorporate spatial information to varying degrees, it include the compact color moments, color coherence vector and color correlograms [1]. Texture is used to specify the roughness or coarseness of object surface and described as a pattern with some kind of regularity.