Military Digital Library Image Retrieval Technology Realization

Modern military conflicts require that every soldier get acquainted with the performances of the varied weapons and equipments, which guarantees the victory and light casualties. However, it's impossible to demonstrate all the weapons and equipments in the world. Recently, weapon study through information-heavily-loaded military pictures and photos becomes an effective alternative. Therefore, image information retrieval (IIR) is increasingly applied in military. Given that present image information management is still based on pixels instead of contents, with the sharp increase of the military image data, the traditional approach of IIR solely based on texts and key words exposes its limitations and cannot be applied directly to the vision-based retrieval. To make image management highly effective and easy to operate, we need an efficient image analysis and retrieval mechanism, i.e. content-based image processing technology. The advantage of this technology is that combined with certain existing techniques, we can make full use of the calculable features of an image, such as color, texture and shape, to store, manage and retrieve the image without full understanding of it.Owing to some unsolved technological problems, few content-based IIR systems are put into use, especially in the field of military image retrieval. This paper is an explosive discussion on content-based IIR in accordance with military digital library (MDL). Based on the international general metadata standard Dublin Core, we first established the military image metadata, and then analyzed the extraction and description of the visual features such as color, texture and shape. Next we discussed the similarity measurements of visual features, imported fuzzy logic into the distance feature, compared correlative performances, pointed out the disadvantages of space-based geometry functions, and brought forward a distance function. For multi-dimension vector's high dimension nature, we probed into the existing dimension-lowering technology and multi-dimension index technology, and selected the most suitable method to establish multi-dimension index in our system. Combing the available IIR technologies, we designed a comprehensive contend-based IIR system with friendly interface for users, which implemented metadata retrieval, text retrieval and vision-based retrieval. This system offers an effective and efficient retrieval mechanism for the Army to study all the available weapons and equipments with military images.