Marek Skomorowski

Use of random graph parsing for scene labelling by probabilistic relaxation

Abstract A generalization of the relaxation labelling model, in which we operate on graphs of labels rather than pairs of labels attached to segmentation objects is proposed. The proposed approach is based on efficient, O(n2), parsing for graph grammars (Flasinski, 1993). To take into account all variations of an ambiguous (distorted) scene under study, a probabilistic description of the scene is needed. Random graphs are proposed here for such a description.

Application of shape description methodology to hand radiographs interpretation

In this paper, a shape description methodology, introduced by Jakubowski [6] is applied to hand radiographs interpretation, in order to recognize bones borders shapes in the fingers regions. It is shown that the classical approach can be used only for preliminary analysis. Therefore, the improved method, based on fuzzy approach, is considered.

Syntactic recognition of distorted patterns by means of random graph parsing

In syntactic pattern recognition a pattern can be represented by a graph. Given an unknown pattern represented by a graph g, the problem of recognition is to determine if the graph g belongs to a language L(G) generated by a graph grammar G. The so-called IE graphs have been defined in [Flasinski, M., 1993. On the parsing of deterministic graph languages for syntactic pattern recognition. Pattern Recognition 26, 1-16] for a description of patterns. The IE graphs are generated by so-called ETPL(k) graph grammars defined in (Flasinski, 1993). In practice, structural descriptions may contain pattern distortions. For example, because of errors in the primitive extraction process, an IE graph g representing a pattern under study may be distorted, either in primitive properties or in their relations, so that the assignment of the analysed graph g to a graph language L(G) generated by an ETPL(k) graph grammar G is rejected by the ETPL(k) type parsing (Flasinski, 1993). Therefore, there is a need for constructing effective parsing algorithms for recognition of distorted patterns, represented by graphs, which is the motivation to do research. The purpose of this paper is to present an idea of a new approach to syntactic recognition of distorted patterns represented by so-called random IE graphs.

Modified jakubowski shape transducer for detecting osteophytes and erosions in finger joints

In this paper, a syntactic method of pattern recognition is applied to hand radiographs interpretation, in order to recognize erosions and osteophytes in the finger joints. It is shown that, the classical Jakubowski transducer does not distinguish contours of healthy bones from contours of affected bones. Therefore, the modifications of the transducer are introduced. It is demonstrated, that the modified transducer correctly recognizes the classes of bone shapes obtained based on the medical classification: healthy bone class, erosion bone class and osteophyte bone class.

A fuzzy shape descriptor and inference by fuzzy relaxation with application to description of bones contours at hand radiographs

Generalization of string languages describing shapes in order to apply them to analyze a contour of bones in hand radiographs is proposed in this paper. An algorithm to construct a fuzzy shape descriptor is introduced. Next, basing on the fuzzy descriptor, a univocal description by fuzzy interference is realized. In prospects this method will be used to erosion detection of hand bones visible in hand radiographs.

Compartment model of neuropeptide synaptic transport with impulse control

In this paper a mathematical description of a presynaptic episode of slow synaptic neuropeptide transport is proposed. Two interrelated mathematical models, one based on a system of reaction diffusion partial differential equations and another one, a compartment type, based on a system of ordinary differential equations (ODE) are formulated. Processes of inflow, calcium triggered activation, diffusion and release of neuropeptide from large dense core vesicles (LDCV) as well as inflow and diffusion of ionic calcium are represented. The models assume the space constraints on the motion of inactive LDCVs and free diffusion of activated ones and ions of calcium. Numerical simulations for the ODE model are presented as well. Additionally, an electronic circuit, reflecting the functional properties of the mathematically modelled presynaptic slow transport processes, is introduced.

Public Transport Information System for Visually Impaired and Blind People

This paper presents an assistive system for the visually impaired and blind people which helps them using public transport means. The proposed system uses mobile phones as a medium for passenger information system and GPS (Global Positioning System), GSM (Global System for Mobile Communications) and Bluetooth technologies for location and communication purposes. In the proposed system sound messages are given to the blind people via mobile phones which have dedicated software installed. This system has been implemented and tested in public transport in two pilot cities.

Computer aided erosions and osteophytes detection based on hand radiographs

In this paper we present a computer system to detect erosions and osteophytes from hand radiographs, the most common symptoms of rheumatic diseases. The designed, implemented and verified algorithm uses techniques of image processing, image analysis and pattern recognition. In the stages of image processing and image analysis, the locations of metacarpal bones, the outlines of finger bones, the locations and outlines of joints and finally the borders of joint surfaces are identified. In the pattern recognition stage, a shape description language is used for each border of the joint surface to detect the locations of erosions and osteophytes on hand radiographs. The presented algorithm expands on those known from the literature, because besides erosions it also detects osteophytes. Moreover, in contrast to previous systems, it analyses proximal interphalangeal joints and distal interphalangeal joints. The obtained results are satisfactory and very promising. The joints are successfully located in 98.3% of cases. The average mean distance between the borders pointed out by radiologists and obtained from the system varies between 0.094mm and 0.157mm, while the sensitivity and the specificity equal around 70% in most of the cases. Therefore, it can become a basis for the diagnosis of certain diseases. Graphical abstractDisplay Omitted HighlightsWe introduce a new algorithm of local segmentation based on a region growing.We define a new shape description language for syntactic pattern recognition.We present a multi-stage algorithm, which expands on those created so far.We designed, implemented and tested an automatic computer system which detects erosions and osteophytes (the system operator has to only load the image and mark the area of the analysis).

Improved fuzzy entropy algorithm for x-ray pictures preprocessing

The fuzzy entropy algorithm was designed for preprocessing of photos taken in the visible spectrum of light. However it did not produce satisfying results when it is directly applied to X-ray pictures. In this paper we present significant improvements of this approach and apply it to hand radiographs. The noise elimination and the bone contourisation is the task which is studied in this paper. Not only is the algorithm modified but also it is combined with using of median and minimum filters. The presented approach allows us to obtain satisfying noise elimination and clear bone contourisation.

Fuzzy-aided Parsing for Pattern Recognition

In syntactic pattern recognition a pattern is represented by abstract data, for instance a graph. The problem of recognition is to determine if a pattern, represented by the describing graph, belongs to a language L(G), generated by a graph grammar G. The so-called IE graphs can be used for a pattern description. They are generated by so-called ETPL(k) graph grammars. The purpose of this paper is to present an idea of a new approach to syntactic recognition of fuzzy patterns represented by fuzzy IE graphs, followed the example of random IE graphs. This methodology can be used for analysis of wider class of patterns and scenes than the one described by the classical syntactic methods. In this paper, apart from the presentation of the fuzzy-aided approach, it is also shown that the probabilistic-syntactic approach is a special case of the presented one.