Region-based Image Retrieval(RBIR) is a sub-branch of Contentbased Image Retrieval(CBIR).It employs image segmentation to extract local visual feature and retrieves images by similarity matching.However

as precise image segmentation is still immature

the performance of RBIR systems is subject to redundant and inaccurate segmentation.In order to reduce adverse effect of image segmentation in RBIR

a new method based on partition of foreground and background is proposed.In the method

image segmentation regions are obtained by applying regular block

classification and valid region location.And the principal object is extracted using the Central Object Extraction Algorithm(COEA).Then images are retrieved by similarity matching based on extracted color and texture feature.In the paper

a RBIR system named ObFind is implemented according to the proposed method.The experimental results show that the proposed method not only has comparable performance to SIMPLIcity but also reduces computation complexity.