Topic -Specific Synopses and Publications: Theories of Visualization | Video Visualization | Glyph-based Visualization | Volume graphics, Visualization, and Deformation | Perception, Cognition and Empirical Studies | Visual Analytics | Real World Applications
In the scientific world, a theory is a fact-based framework for explaining a set of observed phenomena or events. It is typically formulated to facilitate falsifiable predictions about some causal relations. It often involves quantitative measures. Although visualization is a ubiquitous technology and there are many pieces of wisdom for steering various design processes, so far no major theory has been widely accepted to underpin the field of visualization. As humans play an integral part inside the "box" of visualization, this poses a significant challenge in establishing a theory (or theories) of visualization. While information theory, which underpins tele- and data communication, has shown to be applicable in many aspects of visualization, it becomes inadequate when we consider various phenomena of perception, cognition, emotion and interaction in visualization. While it is a piece of computer-assisted technology, visualization cannot distance itself from fundamental questions (e.g., what is truth, data, information, or knowledge?), some of which have been explored by philosophers for thousands of years.
Visualization researchers are inspired to discover theories that can explain why and how visualization works. The building blocks of such a theory include observations and evidence obtained from empirical studies, quantitative metrics for measuring causes and effects, and some mathematical frameworks.
I have started footnoting my personal journeys exploring theories of visualization and perception, cognition and empirical studies in visualization.
Some references on this topic can be found here.
The image on the left was created by Min Chen, see DOI for further details.
Video visualization is concerned with the creation of a new visual representation from an input video to reveal important features and events in the video. It typically extracts meaningful information from a video and conveys the extracted information to users in abstract or summary visual representations, which are typically more compact than the input video itself. Video visualization is not intended to provide fully automatic solutions to the problem of making decisions about the contents of a video. Instead, it aims at offering a tool to assist users in their intelligent reasoning while removing or reducing the burden of viewing videos. In particular, it can be used to fill in many gaps in practice where automated computer vision is yet to provide usable solutions. This aim justifies deviation from the creation of realistic imagery, and allows simplifications and embellishments, to improve the understanding of the input video. The fundamental challenge is: Can we see time (i.e., temporal information) without using time (i.e., an animation)?
I have started footnoting my personal journeys exploring video visualization.
You may also find a bit more about video visualization at http://www.oerc.ox.ac.uk/projects/video-visualization.
The image on the left was created by Ralf Botchen, see DOI for further details.
Glyph-based visualization is a common form of visual designs where a data set is depicted by a collection of visual objects referred to as glyphs. In a broad interpretation, a glyph is a small visual object that can be used independently or constructively to depict attributes of a data record or the composition of a set of data records. Each glyph can be placed independently from others, while in some cases glyphs can also be spatially connected to convey the topological relationships between data records or geometric continuity of the underlying data space. As glyphs are miniature visualizations, they are particularly suitable for studying many theoretical concepts in visualization. In particular, a glyph representation scheme is a coding scheme, which can be studied under the framework of information theory.
Although any glyph-based visualization method will incur the cost and inconvenience of learning and memorization, there have been sufficient evidence to confirm the learnability of carefully-designed glyphs in practice. For example, traffic signs, which typically feature 3 visual channels (e.g., shape, color and a word, number or pictogram), have been learned by billions of people. Glyphs are also the lexical building blocks of many diagrammatic schemes, which feature grammatical rules for topological and hierarchical connections. Hence if there were a common visual language for visualization one day in the future, glyphs would no doubt be its vocabulary. Surely this is one of the ultimate goal of visualization research, regardless how such a language may be shaped.
The image on the left was created by Eamonn Maguire, see DOI for further details.
More web-content on this topic is being developed.
Volume graphics is concerned with graphics scenes, where models are defined using volume representations instead of, or in addition to, traditional surface representations. It is a study of the input, storage, construction, manipulation, display, and animation of volume models in a true three-dimensional (3D) form. Its primary aim is to create realistic and artistic computer-generated imagery from graphics scenes comprising volume objects, and to facilitate the interaction with these objects in graphical virtual environments.
Volume visualization is also concerned with volume data representations that are used to store measured physical attributes of real-world objects and phenomena, or to represent computer-generated models and their attributes in volumetric forms. Although it is typical and conventional for volume datasets (such as in computed tomography) to correspond spatially to the 3D physical world, it is also common in some visualization applications to use volume datasets to store non-spatial physical data as well as abstract information.
The image on the left was created by Carlos Correa, see DOI for further details.
More web-content on this topic is being developed.