Vol. 16 (2007):
  Abstracts of Papers

No. 1/2: Special Issue on Creativity and Visual Design Computing,
No. 3,
No. 4.

15 (2006)	main

Editorial Office, MGV
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Machine GRAPHICS & VISION, Vol. 16 (2007), No. 1/2:

Grabska E.:
Guest Editorial: Creativity and Visual Design Computing.
MGV vol. 16, no. 1/2, 2007, pp. 3-4.

Borkowski A., Grabska E., Ozimek A., Ozimek P., Papiernik K.:
Supporting conceptual design in architecture by linguistic model.
MGV vol. 16, no. 1/2, 2007, pp. 5-22.

It is shown that linguistic approach can be very useful when developing software supporting conceptual design in architecture. Treating primitives, like rooms, as letters of a certain language and capturing the knowledge about the architecture in a grammar allows us to implement automatic reasoning. It turns out that grammars describing hierarchical graphs are best suited for this purpose. The formalism underlying this approach is presented together with a prototype software that allows the user to convert functional requirements into layouts of the designed building, to visualise the resulting alternative solutions and to select the best one for the detailed design. The usage of this software is demonstrated on two examples.
Key words: hierarchical graph, realisation scheme, conceptual design.

Grabska E., Lachwa A., Slusarczyk G., Grzesiak-Kopec K., Lembas J.:
Hierarchical layout hypergraph operations and diagrammatic reasoning.
MGV vol. 16, no. 1/2, 2007, pp. 23-38.

This paper deals with a new, computer-aided approach to floor-layout design. The approach proposes: firstly, a specific layout language with a syntactic knowledge defined by means of hierarchical hypergraphs; secondly, a correspondence between layout modifications and hypergraph operations. An initial layout drawn by the designer is automatically converted into a hypergraph and each designer's modification to the layout is reflected in the hypergraph structure. Our new approach is illustrated by a step by step example, where two complementary representations of the same floor-layout design are used.
Key words: floor-layout, innovative design, hypergraph, diagrammatic reasoning.

Bielecka M.:
Syntactic segmentation of function graph type of curves.
MGV vol. 16, no. 1/2, 2007, pp. 39-55.

In this paper structural analysis of patterns being a special type of curves is presented. The recognized objects are segmented according to their structural properties into primitive patterns representing generic shapes. Then, an algebraic formula describing the structure of the analyzed curve is created. The description is unique.
Key words: curve description, shape analysis, structural description, curve segmentation.

Cowell J., Hussain F.:
A syntactic recognizer for Arabic characters.
MGV vol. 16, no. 1/2, 2007, pp. 57-83.

Commercial OCR systems for high quality Latin characters are widely available. However, the recognition of Arabic characters, particularly those of poor quality, is still an important research area. This paper gives details of two recognition systems for isolated Arabic characters based on the extraction of critical features. The limitations of this approach and its successful extension to a syntactic recognition system are discussed. The syntactic system uses a new web grammar, in which the critical features are nodes and a set of operators describes the spatial relationships between them. The approach used is insensitive to variations in the size and orientation of the characters and even the relative lengths of strokes. The described system has been implemented and the theoretical behaviour of this approach is supported by the experimental results.
Key words: syntactic pattern recognition, web grammars, OCR, Arabic characters.

Slusarczyk G.:
Computer animation in creative design.
MGV vol. 16, no. 1/2, 2007, pp. 85-104.

The paper proposes a new approach to graphic design with the use of computer animation. The class of designs considered are periodic patterns. First, the characterization of rosettes, borders and periodic planar designs is given. Then, a generative system which produces a great variety of periodic designs is equipped with animation. As in-between animation frames ensure the continuity and fluidity of pattern movement, a dynamic continuous design space is obtained. The changes in pattern symmetry groups which result from the use of animation are described. The role of animation in supporting perception of the emergent shapes in the generated patterns is also mentioned. The paper is illustrated by periodic designs produced by the DARTAN animated generative system.
Key words: graphic design, periodic patterns, generative system, computer animation.

Goinski A., Nikiel S.:
The motion of impostors.
MGV vol. 16, no. 1/2, 2007, pp. 105-116.

We describe a method that brings to life impostor-based environments. In a typical scene, supporting objects are rendered as two-dimensional texture maps always facing the camera. Billboards reduce complexity of objects to high extent. In such a representation, spatial properties of depicted objects are lost. Billboards are usually motionless in order to compress the video memory space. In our technique, we introduce 2.5D morphing with respect to the memory footprint. Minimum two textures are required to animate the billboard. Moreover, the whole process is automated and exploits a programmable GPU. As a result, the main application overhead is reduced. The method is designed for vegetation modeling, but can be easily extended to far- and middle-distance shots of humans.
Key words: 3D graphics and realism, morphing, surface deformation, image-based rendering, impostors, animation, billboards.

Janaszewski M., Kacki E.:
Feature generation from digital images using pseudo-fractal algorithm and its four modifications.
MGV vol. 16, no. 1/2, 2007, pp. 117-138.

The main aim of the paper is to present the authors' original method of feature generation from digital images and to report on a comparison of five various algorithms, which implemented that method. The algorithms are based on an idea by the same authors', which consists in producing a quantitative description of similarity intensity between various parts of an image in various scales. To develop it the algorithms take advantage of fractal coding based on an Iterated Function System. Therefore, the generated features can rightly be called similarity features. In this paper we show that similarity features, when combined with other well known ones, can improve recognition results in some image classification tasks. After presenting how the algorithm works, we compare their properties and report the classification results obtained in two different pattern recognition experiments. Moreover, the paper contains a discussion of the obtained results, and of possible future applications of the similarity features.
Key words: pattern recognition, feature generation, texture analysis, self-affinity.

Wang K., Zheng N., Qi H.:
Least square image matting.
MGV vol. 16, no. 1/2, 2007, pp. 139-152.

This paper addresses the well-known problem of natural image matting. Most of the previous matting algorithms require the user to define the tri-map, which is an inconvenient work and sometimes a burden, especially in a complex situation. This paper uses ceratain user defined foreground and background strokes to estimate the image matte. First we use a Gauss Markov random field to model the matting problem. Then we use the least square optimization approach to solve it. Experimental results show that our approach could properly handle confused boundaries. It also could deal with semi-transparent conditions such as fire etc.
Key words: matting, image processing, least square.

Ali Md. H., Rahman I.S., Islam M., Shahiduzzaman M.:
Mathematical morphology based automated control point detection from human facial image.
MGV vol. 16, no. 1/2, 2007, pp. 153-170.

The ultimate goal of this research is to incorporate facial animation based on image morphing in a very narrow bandwidth video transmission, especially in video conferencing, news telecast etc., where the background as well as the object in the image change little. As a part of the whole work, in this paper, an efficient mathematical morphology-based facial feature control point detection technique is proposed. By facial feature control point we mean facial feature (i.e. eye, lip etc.) surrounding points and other important points in the face which can be utilized to create facial animation based on image metamorphosis. In the experiment, mathematical morphology tools are used both for filtering and pattern matching. At first, intensity-independent, color-based segmentation is used with some morphological processing on the input image to separate skin regions. Then, the parallel eye segments are searched by erosion of the edge-thinned image with eye corner structuring elements. By combining them, the probable eye segment pair is identified. Then, using facial structural knowledge, the lips and other control points are detected. The accuracy of the proposed method is within quite acceptable limits; moreover, the method is capable of working with images of average quality or close to average quality.
Key words: facial feature detection, mathematical morphology.

Bielecki A., Strug B.:
Finding an iterated function systems based representation for complex visual structures using an evolutionary algorithm.
MGV vol. 16, no. 1/2, 2007, pp. 171-189.

This paper presents an approach to the IFS inverse problem based on evolutionary computations. Having a bitmap image, we look for a set of functions that can reproduce a good approximation of a given image. A method using a variable number of mappings is proposed. A number of different crossover operators is described and tested. The possibility of enriching evolutionary algorithms by a specific type mechanism characteristic for replication of influenza viruses is discussed. The genetic material of the influenza type A virus consists of eight separate segments. In some types of tasks, such a structure of a genome can be more adequate than representation that consists of one sequence only. If influenza virus strains infect the same cell, then their RNA segments can mix freely, producing progeny viruses which represents the reasortment mechanism. Furthermore, mistakes leading to new mutations are common. The structure of problems for which such viral reproduction mechanisms can be effective are analyzed. The paper ends with some experimental results showing the images we were able to generate with the proposed method. The preliminary experimental results suggest that the introduction of the reasortment operator results in achieving satisfactory images in a smaller number of generations.
Key words: hierarchical evolutionary algorithms, image generation, iterated function systems inverse problem, viral replication, reasortment.

Rataj A.:
Generalization of raster images containing patterns featuring stochastic repetitiveness.
MGV vol. 16, no. 1/2, 2007, pp. 191-201.

The issue of reconstruction of missing or unreliable parts of an image is one of the basic problems in image processing. For example, there are a number of methods for texture generation on the basis of a small sample. This paper presents a method that `bottlenecks' an image processing feedforward neural network so that only some basic traits of the image are preserved. These basic traits are in turn used to generalize the image, thus filtering out any unusual parts of the image.
The ability of neural networks and several other learning machines to generalize is based on the premise of smoothness of the generalizing function. Thus, in order to detect advanced patterns that exhibit complex traits like repetitiveness, instead of training these machines directly with raw data, transforms of the patterns like the Fast Fourier Transform are sometimes performed. In this paper it is shown, that a simple feedforward neural network, without any pre--processing of the training data, using the described `bottleneck' architecture, can properly predict a stochastically repetitive pattern in a raster image.
Key words: generalization, feedforward neural networks, nonlinear regression.

Machine GRAPHICS & VISION, Vol. 15 (2007), No. 3:

Machine GRAPHICS & VISION, Vol. 16 (2007), No. 4:

15 (2006)	main