Visualization, scientific visualization

`visualize': to form a mental vision, image, or picture of (something not visible or present to the sight, or of an abstraction); to make visible to the mind or imagination.
Oxford English Dictionary, 2nd edition, 1989

In science often large and/or complex collections of data have to be processed. Usually it is not suitable for human researchers to investigate such data-sets by reading lists of numbers or other textual representations. The mapping of information into graphs or images, i.e., visualization, was identified as a powerful tool for data investigation already a long time ago.

  

Figure 1.1: Two examples of early flow visualization by Leonardo da Vinci (images out of ``Frontiers of Scientific Visualization'' by Pickover and Teksbury [65]).

Leonardo da Vinci (1452-1519), for example, already used drawings to communicate scientific results. Fig. 1.1 shows two examples of his work. More recently, the extensive use of computers for data processing generated a new need for elaborated visualization techniques. In the early 1990s annual-conference series, solely focusing on visualization, e.g., the ``EUROGRAPHICS Workshop on Visualization in Scientific Computing'' or the ``IEEE Conference on Visualization'', were established. Ten years later already a few compendia on visualization are available as comprehensive text books, for example, ``Scientific Visualization'' by Gregory Nielson, Hans Hagen, and Heinrich Müller [59]. To illustrate the role visualization is playing at the end of the first millennium, some of the most important application fields are listed below:

Medical data visualization -

(anatomic) data is acquired through measurement devices, e.g., MRI or CT, which is then presented using volume visualization techniques, e.g., direct volume rendering or iso-surface extraction.

Flow visualization -

vector data, either computed by flow simulation, or measured data using experimental setups, is plotted for the purpose of data investigation. For example, the design of new aircrafts can be checked using simulation and visualization without constructing expensive prototypes.

Geographic information systems (GIS) and visualization -

for hundrets of years up to now maps are used as visualization of geographic data. Techniques like color coding, height fields, iso-lines, and icons, are used to show topographic information like mountains, rivers, etc., together with additional information, for example, temperature.

Information visualization -

big databases, multi-modal data, and abstract data (usually non-scientific data) increasingly require appropriate visualization techniques. Business data visualization (charts, diagrams, and graphs) is already widly used to illustrate economic data and relationships.

Visualization of microscopic data -

molecules and/or atomic structures investigated in biology, chemistry, and physics, increasingly are visualized for analysis. Also data acquired by non-optical microscopes usually needs to be visualized before investigation can start.

Large-scale data and visualization -

astronomy, for instance, deals with data that is simulated or measured at a scale that prohibits direct investigation in most cases. Again, visualization can help to ``fit'', for example, the entire universe into the study room of an astronomer.

Architectural visualization -

Planning of urban regions as well as buildings is enhanced by visualization methods. New buildings, are visualized on the basis of computer aided design (CAD) data together with existing context. This allows to evaluate plans before actual construction.

Archeology and visualization -

to investigate archaic cultures, for instance, visualization enables researchers to imagine life, habits, rites, etc., in former ages. Reconstruction of historic buildings using visualization is an area of increasing importance.

Visualization aims to maximally exploit the visual channel to the human user for information communication. Visual resolution, spatial as well as temporal, and `resolution' of the human perceptional capabilities restrict the content of information that can be conveyed to the human user through visualization.

mailto:helwig@cg.tuwien.ac.at.