V. Di Gesù

Mathematical Morphology Based on Fuzzy Operators

A vision procedure may be considered as the repeated application of image operators until the vision goal is reached. The type of these operators and the spaces on which they are defined and act depends on the specific problem and on what we are searching on the image. Morphological operations, as filtering, edge detection, skeletonizing, and so on, are mainly required at low and medium levels of the vision procedure, where local and global knowledge is used to enhance the image information content, before a final decision about the image is taken.

A distributed architecture for autonomous navigation of robots

The paper shows a distributed architecture for autonomous robot navigation. The architecture is based on three modules that are implemented on separate and interacting agents: the target recognizer, the obsta90cle evaluator and the planner. An adaptive genetic algorithm has been studied to identify mechanisms for reaching the target and for manipulating the 2-directions of the robot; the distributed architecture has been embedded in the DAISY (Distributed Architecture for Intelligent System). Experiments have been carried out using a LEGO intelligent brick.

Features selection and `possibility theory'

Abstract A method is presented that uses both ‘cluster analysis’ and ‘possibility theory’ to select the most significant variables in multidimensional data. The method is applied to a set of biomedical data from electron spin resonance spectroscopy measurements on patients with a brain injury.

Content-based indexing of image and video databases by global and shape features

Indexing and retrieval methods based on the image content are required to effectively use information from the large repositories of digital images and videos currently available. Both global (colour, texture, motion, etc.) and local (object shape, etc.) features are needed to perform a reliable content based retrieval. We present a method for automatic extraction of global image features, like colour and motion parameters, and their use for data restriction in video database querying. Further retrieval is therefore accomplished, in a restricted set of images, by shape feature (skeleton, local symmetry moments, correlation, etc.) local search. The proposed indexing methodology has been developed and tested inside JACOB, a prototypal system for content-based video database querying.

A fast recursive algorithm to compute local axial moments

The paper describes a fast algorithm to compute local axial moments used in the algorithm of discrete symmetry transform (DST). The basic idea is grounded on fast recursive implementation of respective linear filters by using the so-called primitive kernel functions since the moment computation can be performed in the framework of linear filtering. The main result is that the computation of the local axial moments is independent of the kernel size, i.e. of the order O(1) per data point (pixel). This result is of relevance whenever the DST is used to face with real time computer vision problems. The experimental results confirm the time complexity predicted by the theory.

Some statistical properties of the minimum spanning forest

Abstract A minimum spanning forest method is described which finds cluster patterns in a random graph of points. A relation between the main number of clusters and a defined fixed thresholding value is obtained. Then, using the number of clusters as a parameter, a uniformity test suitable for low statistics data sets is proposed. Finally, some effective applications on simulated and real data are also discussed.

Finding essential features for tracking starfish in a video sequence

The paper introduces a software system for detecting and tracking starfish in an underwater video sequence. The target of such a system is to help biologists in giving an estimate of the number of starfish present in a particular area of the sea-bottom. The nature of the input images is characterised by a low signal/noise ratio and by the presence of noisy background represented by pebbles; this makes the detection a non-trivial task. The procedure we use is a chain of several steps that starts from the extraction of the area of interest and ends with a classifier and a tracker providing the necessary information for counting the starfish present in the scene.

M-VIF: A machine-vision based on information fusion

The authors describe a new architecture for machine vision, which is based on information fusion approach. Its general design has been developed by using a formal computation model that integrates three main ingredients of the visual computation: the data, the models, and the algorithms. The hardware design and the software environment of M-VIF are also given. The simulation of M-VIF is under development on the HERMIA-machine.

Fuzzy mathematical morphology to analyse astronomical images

Traditionally, astronomical data are represented by images. X- and gamma-ray telescopes have been designed in order to produce images in these ranges of energy. Data are characterized by low signal embedded in structured background. The paper introduces a new approach, based on fuzzy-morphology, to restore and retrieve structural properties of such images. Experimental results are shown on astronomical images in order to evaluate the methodologies introduced.<<ETX>>

The iconic interface for the PIctorial C language

Iconic environments intend to provide expressive tools to implement, to debug and to execute programs. Moreover its pictorial constructs guide the user to design algorithms in an interactive fashion. Visual interfaces are especially required whenever programs run on an heterogeneous and reconfigurable multiprocessor system oriented to image analysis. Pictorial tools help the user to control the scope of variables, and the distribution of the tasks into the processors. In this paper, the general design, the visual-syntax, and the implementation of the first prototype of an iconic user interface for the PIctorial C Language (PICL) are described.<<ETX>>