Research And System Implementation On Trademark Image Retrieval

Content based image retrieval is to perform the similarity retrieval according to the image features representing the image content, which may be extracted in the generic or specific domain. Specific domain based image retrieval can benefit from the useful domain knowledge and the corresponding retrieval results can meet the user's requirement better than the generic one. With the development of market economy the trademark plays the more and more important role in the current society and the content based image retrieval technique has been widely used in the trademark domain. This paper does research mainly on content based trademark image retrieval, especially on subblock-based image retrieval, presenting a new subblock-based image retrieval method under the polar coordinate system for retrieving trademark image, and designs trademark tmage retrieval system based on integrated features.The subblock-based image retrieval uses global and local image features to retrieve trademark image. The image is partitioned into several subblocks, Each subblock image features reflect the image local information and the combination of multiple subblocks' image features describe the whole region shape. This paper proposes a subblock-based image retrieval method under the polar coordinate system for retrieving trademark image. After preprocessing the trademark image, the regular binary-image is obtained. Then, the minimum circumscribed circle and shape principal orientation of the object region are calculated; and the object region is divided into some blocks in the polar coordinate, which uses the center of the minimum circumscribed circle as the origin and the direction of the shape principal orientation as the direction of the polar axis,and the features of all subblocks are extracted to compose shape histograms and then smoothed; Then, combined with global features to synthetically represent the content of the image; Finally, a new image similarity is used to compute the distance between images. Experiment results show that this method can keep good invariance under translation, rotation, scale and mirror, and the retrieved results match human visual perception very well.This paper designs a trademark image retrieval system based on integrated features, which is aimed to be an experimental system and can be used to test different retrieval algorithms. It is also very convenient to customize the different subblock-based retrieval methods.