Slawomir Nikiel

Integration of iterated function systems and vector graphics for aesthetics

Fractals are an integral part of many computer graphics applications. Relatively simple implementations of fractal modeling result in an infinite number of complex and attractive images. The subject of fractal image generation is well covered in the literature. Many fractal models are based on a raster representation, which is rather inconvenient for interactive modeling and implementation in 3D graphics. On the other hand, vector-geometry models are very popular in commercial graphics design packages. This creates a demand for vector representation of fractal models. The paper introduces the iterated function systems (IFS) vector-based model along with the supporting rendering algorithm. The solution offers high performance and modeling flexibility. IFS, when combined with vector graphics, offer new forms of artistic expression.

Deployment algorithm using simulated annealing

In this paper, a novel information design algorithm is proposed. It is based on the simulated annealing, which is regarded as one of the important meta-heuristic optimization methods. The idea behind our algorithm originates from the search for optimal solution, where selection avoids local minima. The simulated annealing model is used in the construction of diagrams depicting heating systems. The method offers an automated visual design tool, useful in CAD1 construction of complex systems. The paper discusses the theoretical background, the properties of the proposed algorithm alongside with the sample application prototype outputs.

A Proposition of Mobile Fractal Image Decompression

A Proposition of Mobile Fractal Image Decompression Multimedia are becoming one of the most important elements of the user interface with regard to the acceptance of modern mobile devices. The multimodal content that is delivered and available for a wide range of mobile telephony terminals is indispensable to bind users to a system and its services. Currently available mobile devices are equipped with multimedia capabilities and decent processing power and storage area. The most crucial factors are then the bandwidth and costs of media transfer. This is particularly visible in mobile gaming, where textures represent the bulk of binary data to be acquired from the content provider. Image textures have traditionally added visual realism to computer graphics. The realism increases with the resolution of textures. This represents a challenge to the limited bandwidth of mobile-oriented systems. The challenge is even more obvious in mobile gaming, where single image depicts a collection of shots or animation cycles for sprites and a backdrop scenery. In order to increase the efficiency of image and image texture transfer, a fractal based compression scheme is proposed. The main idea is to use an asymmetric server-client architecture. The resource demanding compression process is performed on the server side while the client part decompresses highly packed image data. The method offers a very high compression ratio for pictures representing image textures for natural scenes. It aims to minimize the transmission bandwidth that should speed up the downloading process and minimize the cost and time of data transfer. The paper focuses on the implementation of fractal decompression schemes suitable for most mobile devices, and opens a discussion on fractal image models for limited resource applications.

Chaos & Graphics: A recursive subdivision scheme for isosurface construction

In the paper, we propose a new method for isosurface construction. We apply a recursive subdivision scheme widely known in fractal terrain synthesis to create a hierarchical mesh over a set of volumetric points. The algorithm starts from an explicit polygonal mesh representing a cube. The main applies a wrapping-like projection in recursive manner with sampling volumetric space along a vector normal in both directions. The algorithm allows for geometry compression and isosurface reconstruction, and follows the idea of the level of detail (LoD). The method is illustrated by example of volumetric escape-time fractals.

Simulation Of Visual Assessment For The Given Deployment Of Graphical User Interface Elements.

We observe a constant growth of methods and models enabling automated generation of graphical data, derived either from physical world or taken from simulations. Good information design is crucial for humancomputer interface, improving productivity and enhancing human understanding. This paper proposes two novel algorithms to simulate the visual assessment of deployment of GUI elements. GUI elements are treated as the uniform rectangular blocks on the layout. Those blocks eventually are replaced by the system dependent object representations, e.g. visual metaphors of the heating system. The results returned by the algorithms were compared with results obtained by a survey. The proposed metrics can be used in visual evaluation of various simulation models, as long as they consist of logically separable elements. The paper discusses the theoretical background, the properties of proposed algorithms alongside with the sample application prototype outputs.

Pocket geocoder — a proposition of GPS-based tagging system for digital photography

Mobile communication presents one of the mainstream research challenges in Information Communication Technologies. GPS, EGNOS and in near future GALILEO, represent technologies that enable implementation of innovative services following the concept of Personal Info-Mobility. The information can be related to time and territory, thus it presents quite interesting opportunities for location-based services. The paper forwards proposition of a tool for the geographical information system combining global positioning system with digital image acquisition. The problem of userpsilas positioning during the image capture is not trivial and addresses both localization and synchronization issues. Information on camera optics, while accompanied by its geographical position and orientation may offer more valuable data for further interpretation and indexing in geographical information systems. While applied on a massive scale, people will be able to use such solutions to record and recall important places in their lives. The proposition of a geo referenced imaging system is described along with description of the working prototype application.

Real-time simulation of a sailboat

Game programming and real-time simulation systems are usually based on key-framed and motion-capture animations. Introduction of HAVOK and AGEIA PhysX technologies released game developers from some burden of predefined animation paths and shifted problem to autonomous modeling of physics. Recent developments of graphic shader languages along with the interoperability of COLLADA opens path to interchange of geometry, textures and physics between different run-time environments. Real-time computer graphics systems are currently limited to rigid-body physics that is in sharp contrast with off-line rendering environments. The paper presents a proposition of real-time simulation of a sailboat exploring both rigid-bodies and soft-bodies. The elastic model is based on cloth simulation without ripping capability.

Implementation of Poisson Faulting Algorithm with Circular Fault Function for Hardness Data Synthesis

Natural erosion processes depend often upon terrain internal structure. Modelling such phenomena is very important in GIS-related (Geographic Information System) and computer graphics areas. Virtual environments takes advantage on improved realism of the images while GIS-based models benefits from plausible simulation output for urban development, landscape design or military disaster relief training. In cases, where terrain structure data cannot be derived from real geological records we can use physically-inspired models and use synthetic environments for simulation of wide class of terrains. This paper proposes a technique for generation of ground structure models related to their hardness. The method is based on the modified Poisson Faulting algorithm, that was originally used by Mandelbrot and Voss to generate fBs (fractional Brownian surfaces). The model defines hardness data to be simulated with regard to different geological materials and can be used to broaden variety of terrain models based on DEM (Digital Elevation Model) or height-field representation. We discusses the proposition of extending fractal generated terrain with hardness records. We use circle-based fault function for the Poisson Faulting algorithm. The results visually resemble natural objects observed in cross-section of soil and are highly similar to cross-section in open pit-mines. In contrast to a classic fractal parameter-driven models our proposition is a data-driven model for terrain synthesis, opening possibilities for dynamic simulations.

Visual Rating for Given Deployments of Graphical User Interface Elements Using Shadows Algorithm

Good information design is very important for human computer interfaces since it improves productivity and enhances human understanding. This paper proposes a novel algorithm for estimation of deployment of the visual elements of the GUI. The interface layout can be either created manually or be the output of computer simulation locating uniform rectangular blocks on the layout. Those ‘black-box’ blocks can be replaced by the system dependent objects representations, e.g. visual metaphors of the heating system. The proposed “shadows” algorithm can be used in visual rating of various GUI models. The paper discusses the theoretical background, the properties of the proposed algorithm together with the sample prototype application.

Aesthetic-Driven Simulation of GUI Elements Deployment

We observe increasing complexity of Information Systems that is seemingly in contrast to constant limits of human perception. In order to handle this intricacy, various automated or semi-automated methods for data visualization are implemented. Graphical User Interface design is very important for human-computer interaction since it improves productivity and enhances human understanding. This paper proposes the novel algorithm for estimation and deployment of the visual elements of the GUI layout. The layout is composed of the blocks, that eventually are replaced by the system dependent object representations, e.g. visual metaphors of the heating system. The paper discusses the theoretical background, the properties of proposed algorithms together with the sample prototype application.