This paper describes the retrieval process from image databases, based on a description of the image content. This process is based on the assumption that a semantic interpretation of the image content is available, as the result of an automatic or semi-automatic image analysis process, applied to images belonging to specific domains and described in advance of the system. The image query language allows the user to express conditions on the symbolic representation of the images to be retrieved. It addresses the important aspects of the various image interpretations resulting from image analysis, such as partial conditions on the composition of complex objects in the image, their degree of recognition, and positional requirements on the objects in the image interpretation. The paper outlines image query processing, with particular emphasis on the access structures to support fast content-base image retrieval.