Giró-i-Nieto X, Marqués F, Marcello J, Eugenio F. MPEG-7 Descriptors for Earth Observation Satellites. In International Astronautical Congress. Houston, Texas (USA): Inernational Astronautical Federation; 2002. pp. 1–4.  (267.36 KB)


The amount of digital multimedia information has experienced a spectacular growth during the last years thanks to the advances on digital systems of image, video and audio acquisition. As a response to the need of organizing all this information, ISO/IEC has developed a new standard for multimedia content description called MPEG-7. Among other topics, MPEG-7 defines a set of multimedia descriptors that can be automatically generated using signal processing techniques. Earth Observation Satellites generate large quantities of images stored on enormous databases that can take advantage of the new standard. An automatic indexation of these images using MPEG-7 meta-data can improve their contents management as well as simplify interaction between independent databases. This paper gives an overall description on MPEG-7 standard focusing on the low-level Visual Descriptors. These descriptors can be grouped into four categories: color, texture, shape and motion. Visual Color Descriptors represent the color distribution of an image in terms of a specified color space. Visual Texture Descriptors define the visual pattern of an image according to its homogeneities and non-homogeneities. Visual Shape Descriptors describe the shape of 2D and 3D objects being, at the same time, invariant to scaling, rotation and translation. Motion Descriptors give the essential characteristics of objects and camera motions.


These descriptors can be used individually or in combination to index and retrieve satellite images of the Earth from a database. For example, oceans and glaciers can be discerned based on their Color Descriptors, also cities and desert based on the Texture Descriptors, island images can be grouped using the Shape descriptors and cyclone trajectories studied and compared using Motion Descriptors.