Do you see what I mean?

Visualizers, like logicians, have long been concerned with meaning. Generalizing from MacEachren's overview of cartography, visualizers have to think about how people extract meaning from pictures (psychophysics), what people understand from a picture (cognition), how pictures are imbued with meaning (semiotics), and how in some cases that meaning arises within a social and/or cultural context. If we think of the communication acts carried out in the visualization process further levels of meaning are suggested. Visualization begins when someone has data that they wish to explore and interpret; the data are encoded as input to a visualization system, which may in its turn interact with other systems to produce a representation. This is communicated back to the user(s), who have to assess this against their goals and knowledge, possibly leading to further cycles of activity. Each phase of this process involves communication between two parties. For this to succeed, those parties must share a common language with an agreed meaning. We offer the following three steps, in increasing order of formality: terminology (jargon), taxonomy (vocabulary), and ontology. Our argument in this article is that it's time to begin synthesizing the fragments and views into a level 3 model, an ontology of visualization. We also address why this should happen, what is already in place, how such an ontology might be constructed, and why now

Components, Frameworks and GKS Input

This paper was inspired by the Components/ Frameworks approach to a Reference Model for computer graphics, currently under discussion in the ISO computer graphics subject committee. The paper shows how a formal description of the GKS input model may be given in Hoare's CSP notation and explores some extensions in which some of the components in the GKS model are replaced by more interesting ones. The paper thus demonstrates some of the power and flexibility inherent in the Component/ Frameworks idea. The use of a formal notation led to a deepening of the authors' understanding of the input model and suggested some different ways of looking at the input model

Image Communication Open Architecture

Standards for imaging and communication have been developed separately and in isolation from each other. Moreover, even the standards for imaging have been developed in an uncoordinated manner, each addressing the needs of a particular application area. Terminology has been developed in different areas such that the same terms are used to mean different things. AMICS give the opportunity, through its work to develop an Image Communication Open Architecture (ICOA), to characterize images, leading to the production of a framework, which identifies the operations on images, and to relate these operations to the required standards. The ICOA enables the various standards and standardization activities both in the imaging area and in the wider area of image communication to be related and the necessary support tools to be identified. The ICOA framework encompasses several components: A characterization of images was elaborated. Several standards were inspected with respect to images accordin g to information and data structures, communication and other aspects, as storage, processing, management, and identification. Services were inspected in order to identify specific requirements for image communication. A Mathematical model for digital images was defined. A reference model for image formats, which comprises a set of distinct criteria was derived. Conversion aspects were inspected. A comprehensive image data model (ICOA Image Data Model) was defined which can be used to describe any kind of digital image. The relation of digital images to multi/hypermedia information and to international standardization efforts was inspected to provide means for applications wishing to embed images into a multi/hypermedia environment. In regard to software development, the ICOA framework was used as the basis for the development of the ICOA Image Handler (IIH). The purpose of the IIH is the storage and retrieval of digital images whether they are stored locally or remotely. The IIH addr e sses open communication aspects encompassing the handling of various compression schemata and image formats as well as different conversion functionalities. In order to highlight requirements of other RACE projects for the ICOA a questionnaire was developed and distributed. The evaluation of the questionnaire showed the necessity for the ICOA framework