2007 | 5 Themenheft

Browsing 2007 | 5 Themenheft by Issue Date

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  • Journal Issue
  • Article
    Image Morphology: From Perception to Rendering
    Buf, Hans Du; Rodrigues, Joao (2007) , S. 98-116
    A complete image ontology can be obtained by formalising a top-down meta-language which must address all possibilities, from global message and composition to objects and local surface properties. In computer vision, where one general goal is image understanding, one starts with a bunch of pixels. The latter is a typical example of bottom-up processing, from pixels to objects to layout and gist. Both top-down and bottom-up approaches are possible, but can these be unified? As it turns out, the answer is yes, because our visual system does it all the time. This follows from our progress in developing models of the visual system, and using the models in re-creating an input image in the form of a painting.
  • Article
    Computational Visualistics and Picture Morphology – An Introduction
    Schirra, Jörg (2007) , S. 1-22
    Pictures have to be formalized digitally in an adequate manner when computer scientists are to work with them. It is mainly the relevant physical properties of the corresponding picture vehicle that have to be considered in that formalization: that is, the picture syntax. The present special issue of IMAGE deals in particular with morphological questions taking the specific, formalizing perspective of computational visualistics. It is also intended as the attempt to offer a clear and easily understandable summary of the state of the art of research on picture morphology in computational visualistics for picture scientists of the other disciplines. As an introduction, the relations between computer science, general visualistics, syntax studies, and morphology are examined.
  • Article
    A Survey of Image-Morphologic Primitives in Non-Photorealistic Rendering
    Isenberg, Tobias (2007) , S. 80-97
    This paper presents an overview of the image-morphologic primitives used commonly in non-photorealistic rendering (NPR), a subdomain of computer graphics that is inspired by a long tradition of artistic and illustrative depiction. In particular, we survey NPR shading, stroke-based rendering, sparse line drawings, graftals, and area primitives. Such primitives usually cover larger regions on the canvas and often carry a meaning beyond the color of the image region they represent. This distinguishes them from the pixel as a primitive used in photorealistic rendering, which does not have any meaning aside from sampling the color of the image section it represents. We give examples to illustrate the individual techniques and briefly mention how they are tracked though the rendering process as well as represented in the final image.
  • Article
    Syntactic Structures in Graphics
    Engelhardt, Yuri (2007) , S. 23-35
    Building upon the existing literature, we are suggesting to regard the building blocks of all graphics as falling into three main categories: a) the graphic objects that are shown (e.g. a dot, a pictogram, an arrow), b) the meaningful graphic spaces into which these objects are arranged (e.g. a geographic coordinate system, a timeline), and c) the graphic properties of these objects (e.g. their colors, their sizes). We suggest that graphic objects come in different syntactic categories, such as nodes, labels, frames, links, etc. Such syntactic categories of graphic objects can explain the permissible spatial relationships between objects in a graphic representation. In addition, syntactic categories provide a criterion for distinguishing meaningful basic constituents of graphics. Based on the above, we discuss how the concept of syntactics can be applied to graphics. Finally we distinguish different types of meaningful graphic spaces that can be used to construct graphics. Throughout the paper we relate our proposals to the relevant existing literature.
  • Article
    Automatic Generation of Movie Trailers using Ontologies
    The SVP Group (2007) , S. 117-139
    With the advances in digital audio and video analysis, automatic movie summarization has become an important field of research. Much of the work has been put into movie abstracting for large media databases. Looking at the topic from a different side, the movie industry has long since perfected the art of summarization in their advertising trailers to attract an audience. In this paper we introduce the approach of automatically generating entertaining Hollywood-like trailers based on a trailer grammar, enhanced by an ontology. The extraction of features from movies using state-of-the-art image and audio processing techniques builds the foundation for the selection of meaningful and usable material, which is re-assembled according to the defined rules. User testing of our automatically produced trailers shows that they are well accepted and in many ways comparable to professionally composed trailers.
  • Article
    Specification of Morphological Models with L-Systems and Relational Growth Grammars
    Kurth, Winfried (2007) , S. 50-79
    Among the techniques for the creation of photorealistic virtual organisms, particularly plants, and in scientific models of vegetation structure, rule-based specifications (formal grammars) play a prominent role. Lindenmayer systems (L-systems) are the most widespread formalism of this sort, but certain types of graph grammars, combined with standard object-oriented programming, offer even more possibilities to specify rule-driven developments of 3-dimensional arrangements, morphology of virtual organisms and underlying processes like, e.g., metabolic reactions. Examples of grammar rules and the virtual geometrical structures generated from them, all realizable with the open-source software GroIMP (www.grogra.de), are shown. This grammar-based approach is often not immediately used for the direct specification of a picture as a pattern of graphical elements in a plane, but for virtual 3-D scenes, which are then rendered visible using standard techniques of geometry- based computer graphics.
  • Article
    Mereogeometry and Pictorial Morphology
    Borgo, Stefano; Ferrario, Roberta; Masolo, Claudio; Oltramari, Alessandro (2007) , S. 36-49
    The paper reviews geometrical approaches in the area of qualitative space representation by discussing formal systems of geometry based on the notion of extended regions (mereogeometries). The focus is on primitives that are cognitively motivated and that capture different notions of naive geometry. The paper then moves to consider the role of mereogeometries (and in particular of the concepts they rely upon) in the domain of picture morphology in two ways: it discusses some primitives that are motivated from the cognitive perspective, and it considers the issue of granularity and refinement.
  • Article
    Conclusive Notes on Computational Picture Morphology
    Schirra, Jörg (2007) , S. 140-153
    As the thematic issue of IMAGE on computational image morphology attempts in particular to mediate between computational visualistics and other disciplines investigating pictures and their uses, the following remarks broaden the perspective again and relate the computational argumentations of the preceding papers to the more general discussion of image science. The two fundamental categories of picture syntax, the geometric base structure and the marker value dimension, are described. They are applied to the questions whether pictures with ill-formed syntax may exist at all, and if so, whether computers can deal with them as well. The overview finally extends the discussion to the limits of pictorial syntax studies.