In the proposed demo, a new approach to e-learning environments for deaf people is illustrated. Using a fully iconic web-based environment, a tutor can define, generate and test e-learning courses for deaf people, which are automatically managed, published and served by the system itself.

Virtual simulators have been used in the last twenty years for applications ranging from flight simulation to computer-based training, just to name a few. More recently a new level of simulation has been introduced thanks to haptic interfaces able to reproduce kinesthetic and/or tactile feedback, typically experimented during interaction with real-world objects. In this paper visual simulation and haptic interfaces are integrated in a novel training system for Intra Cytoplasmic Sperm Injection (ICSI), an in-vitro fertilization technique which is now a standard for the treatment of human infertility. We describe a virtual micromanipulation simulator made by two hand-based Cyberforce haptic devices (a synthetic replica of the actual manipulation gear) and a visual-haptic engine simulating the shape and the dynamic behavior of the main components in the artificial fertilization process: the human egg, the selected sperm and the micro needles required to inject the latter into the egg's cytoplasm. Our first tests, conducted so far, are encouraging.

MADCOW 2.0 is a system for annotation of Web content, supporting the production and exploration of personal and public annotations on text, images and videos in a Web page. Its design starts from the main requirement that the annotation activity does not have to disrupt the normal browsing of Web pages by a user. MADCOW 2.0 allows interaction with the annotated portions of the page to provide access to the annotation content. Conversely, the representation of the existing notes supports different forms of exploration of the Web page, and can become the starting point for further navigation over the Web. A uniform style of interaction has been adopted for creating and accessing annotations on text, images and videos, and some novel solutions have been introduced to cope with overlaps between the annotated portions. The annotation user experience is facilitated by enabling forms of in-place annotation and manipulation of both the annotated portion and the annotation content.

In this work we present a system to encode location based information extracted from a media collection (the Flickr tagging system) into a single 2D physical label. This information is clustered by using locations metadata (geotags) and key-words (tags) associated to pictures. Our system helps two types of users: the user authoring the physical label and the final user who retrieves up-to-date information scanning the label with his/her camera phone. Preliminary results for a given seed word (the tag Napoli) on 3000 photographs are presented, together with some ad-hoc weighting factors that help in finding significant pictures (representing places) that can be associated to a specific area.

The use of the Web and the diffusion of knowledge management systems makes it possible to base discussions upon a vast set of documents, many of which also include links to multimedia material, such as images or videos. This perspective could be exploited by allowing a team to collaborate by exchanging and retrieving annotated multimedia documents (text, images, audio and video). We designed and developed a digital annotation system, MADCOW, to assist users in constructing, disseminating, and retrieving multimedia annotations of documents, supporting collaborative activities to build a web of decision-related documents. We made a strong effort in designing the user interface and we tested it with 24 users. We describe a scenario in which annotation plays a crucial role, where the object of the collaboration is a politically and artistically important palace of Rome, for which the availability of images and historical documentation is fundamental in order to take informed decisions. We demonstrate the MADCOW interface and its use in the restoration team. The annotations can be used to support teamwork as well as to offer the public some reasoned integration and guide to the available material.

Visual interaction involves different types of resources, both at the computational and at the human end of the interaction loop. The roles played by resources, with respect to the development of interactive tasks, are also discussed

We propose a resource-based model of human-computer interaction, and discuss how WIPPOG, a rule-based language for multiset transformations, can support such a model. WIPPOG is here adopted as an enactment mechanism for task models expressed by a visual notation. We exploit this resource-based perspective to model some common interaction errors and suggest possible prevention and mitigation strategies.

The new challenge for designers and HCI researchers is to develop software tools for effective e-learning. Learner-Centered Design (LCD) provides guidelines to make new learning domains accessible in an educationally productive manner. A number of new issues have been raised because of the new "vehicle" for education. Effective e-learning systems should include sophisticated and advanced functions, yet their interface should hide their complexity, providing an easy and flexible interaction suited to catch students' interest. In particular, personalization and integration of learning paths and communication media should be provided.It is first necessary to dwell upon the difference between attributes for platforms (containers) and for educational modules provided by a platform (contents). In both cases, it is hard to go deeply into pedagogical issues of the provided knowledge content. This work is a first step towards identifying specific usability attributes for e-learning systems, capturing the peculiar features of this kind of applications. We report about a preliminary users study involving a group of e-students, observed during their interaction with an e-learning system in a real situation. We then propose to adapt to the e-learning domain the so called SUE (Systematic Usability Evaluation) inspection, providing evaluation patterns able to drive inspectors' activities in the evaluation of an e-learning tool.

Digital annotation of multimedia documents adds information to a document (e.g. a web page) or parts of it (a multimedia object such as an image or a video stream contained in the document). Digital annotations can be kept private or shared among different users over the internet, allowing discussions and cooperative work. We study the possibility of annotating multimedia documents with objects which are in turn of multimedial nature. Annotations can refer to whole documents or single portions thereof, as usual, but also to multi-objects, i.e. groups of objects contained in a single document. We designed and developed a new digital annotation system organized in a client-server architecture, where the client is a plug-in for a standard web browser and the servers are repositories of annotations to which different clients can login. Annotations can be retrieved and filtered, and one can choose different annotation servers for a document. We present a platform-independent design for such a system, and illustrate a specific implementation for Microsoft Internet Explorer on the client side and on JSP/MySQL for the server side.

We present a system supporting synchronous distance multimedia collaboration. Such systems require a number of tools to communicate, enforce collaboration awareness and maintain consistency of shared objects. We introduce the main requirements to provide virtual room facilities, and present our implementation comparing it to other systems

A typical user, when learning, annotates text, figures and other contents, so as to better highlight, memorize, and retrieve relevant information. A few annotation programs exist but either change the contents of the document, or do not support distance learning through the web. We report work-in-progress on a user-centered annotation tool (UCAT) which allows students to annotate, following their personal styles, (using different icons, colors and signed versions) any document belonging to authorware within a course. We have chosen Amaya as the working environment since, belonging to the World Wide Web Consortium (W3C), it complies with the semantic web specifications on document formats, like RDF. An example of the deployment of UCAT will be shown in the paper.

Visual interaction processes are modeled in this paper as sequences of visual sentences in which for each visual sentence only a limited set of user actions is possible. We introduce the notion of "dynamic visual language" as a weakly ordered set of visual sentences characterized by the presence of common elements. We present a formal model of derivation of visual sentences in a dynamic visual language in which each visual sentence specifies the possible actions which can be performed on it and the possible transformations it can go through. In this way, we offer a formal setting in which the interaction process can be formally specified. A user interface can be derived from the formal specification, so that it embeds proper context elements which limit user disorientation. The concepts are illustrated by the user interaction with a prototype of a digital library developed at the University of Bari.

A wide number of algorithms for surface segmentation in range images have been recently proposed characterized by different approaches (edge filling, region growing,...), different surface types (either for planar or curved surfaces) and different parameters involved. Optimization of the parameter set is a particularly critical task since the range of parameter variability is often quite large: parameter selection depends on surface type, sensors and the required speed which strongly of affect performance. A framework for parameter optimization is proposed based on genetic algorithms. Such algorithms allow a general approach that has been successfully applied on different state-of-the-art segmenters and different range image databases.

The title of the panel implies a walk through on different interfaces based on human-dependent assumptions that may condition their implementation, their application and their usability. The nature of the problems encountered when designing a system that should be used by different classes of users - and therfore must satisfy and facilitate access to information to people having varied skills - is manifold. Nevertheless, by designing user-centered interfaces we are trying to improve the quality of work, reduce memory load, enable the detection and extraction of the required information for making evaluations, taking decisions and smoothly progress along a well-defined path until the project termination.The people in the panel have a wide range of experiences in the broad area of multimedia communication and, more particularly, have worked in different communication domains where the spatial view, the environment and the application determine the features of the interface, in some cases considering management and inventory problems, artistic work, data search and navigation activities, in others restoration (and relative documentation) projects with the possibility of monitoring such projects. In particular, the importance of a small scale prototype to verify some of the basic assumptions, which were established at the beginning of the interface design project, must be strongly considered. The purpose of the panel will be to review and discuss the nature of communication for a given set of environments and cultural patterns, debating the nature of some established guidelines and suggesting new ones while also focusing on the specific applications stemming from Cultural Heritage, where the nature of information is complex and multifold: numerical, textual and pictorial. Likewise, the motivation for the users of the proposed systems may differ from one time period to another, so changing goals, methods and actions to be undertaken by such users according to the present status of the activity. Restoration, classification, documentation and presentation are some of the different functions that are typical of the application we are considering and which will be analyzed by the panelists.

We present a combination of techniques which can improve recall in image retrieval systems: a fast image segmentation algorithm suitable for color images which enables one to describe images in a database using multiple segmentations. A simple example shows that the use of a "rich description" satisfies a broader range of queries.

An image processing method for features extraction and segmentation from three-dimensional (3D) image datasets is presented. Kohonen's self-organizing map (SOM) is used to perform segmentation. Previously, the segmentation method worked on a 2D dataset based on a projection of the three-dimensional dataset (Nguyen et al., 1998). Our 3D approach to segment biological images preserves the 3D object orientations with respect to the surrounding cell volume. A few examples from genetics and brain analysis are provided in order to demonstrate the performance of the proposed method.

An image can be regarded as a fuzzy subset of a plane. A fuzzy entropy measuring the blur in an image is a functional which increases when the sharpness of its argument image decreases. We generalize and extend the relation "sharper than" between fuzzy sets in view of implementing the properties of a relation "sharper than" between images. We show that there are infinitely many implementations of this relation into an ordering between fuzzy sets (equivalently, images). Relying upon these orderings, we construct classes of fuzzy entropies which are useful for image thresholding by cost minimization. Assuming the image to be a degraded version of an ideal two level image (object/background), a fuzzy entropy can be introduced in a cost functional to force the fitting function to be as close as possible to a two-valued function. The minimization problem is numerically solved, and the results obtained on a synthetic image are reported.

No abstract available.

A novel definition of visual languages allows a uniform approach to satisfying the needs of visual reasoning faced in visual human-computer interaction. The way the machine associates a computational meaning with an image, and conversely, the way it generates an image on the screen from a computation are formally described. A definition of a visual sentence and of a visual language as a set of visual sentences is discussed. A hierarchy of visual languages is derived in relation to the requirements for intelligible, manageable and trustable interaction between humans and computers.

In the syntactic approach to pattern recognition, patterns are represented as strings, where each pattern is expressed as a composition of its component patterns, called subpatterns and pattern primitives. This approach draws an analogy between the structure of patterns and the syntax of a language. The patterns are considered at a single resolution level, and the recognition of each pattern is usually made by parsing the pattern structure according to a given set of syntax rules, obtained in the first stage of the analysis. This paper describes a pyramidal approach to 2-D object representation which relies on a linguistic description of the object contour at different resolution levels. Our approach, which is parallel and context-sensitive, implies the use of higher dimensional grammars for defining production rules which describe the evolution of the contour between levels. This method is computationally efficient (due to the fast coarse-fine search), rotationally invariant, as well as rather insensitive to noise.

In this paper we suggest a variant of a binary image representation based on run length encoding. This variant allows one to build a "graph representation" for a number of computing tasks like component labeling, computations of Euler number, diameter and convex hull, and the detection of local extrema and multiple points. Finally, a running application in the raster-to-vector conversion of digital maps is provide.

Describes an approach for multiparadigmatic visual access integration of different interaction paradigms. The user is provided with an adaptive interface augmented by a user model, supporting different visual representations of both data and queries. The visual representations are characterized on the basis of the chosen visual formalisms, namely forms, diagrams and icons. To access different databases, a unified data model called the "graph model" is used as a common underlying formalism to which databases, expressed in the most popular data models, can be mapped. Graph model databases are queried through the adaptive interface. The semantics of the query operations is formally defined in terms of graphical primitives. Such a formal approach permits us to define the concept of an "atomic query", which is the minimal portion of a query that can be transferred from one interaction paradigm to another and processed by the system. Since certain interaction modalities and visual representations are more suitable for certain user classes, the system can suggest to the user the most appropriate interaction modality as well as the visual representation, according to the user model. Some results on user model construction are presented.

The method proposed in this paper for two-dimensional object recognition relies on the idea of a structural coding of an object at varying levels of resolution. A tree structure describes the evolution of the contour at increasing levels of detail. Each tree node represents a contour segment through a set of attributes to provide a richer description of the image shape. In addition to the attributes, a weight is associated to each descriptor indicating the significance of the corresponding primitives. An approach for 2D object recognition based on a matching of the attributed tree representation of the candidates with that of the model is proposed.

The quadtree medial axis is a compact image representation that can be used to derive a number of geometrical properties of an image component. A parallel algorithm for computing the quadtree medial axis transform is described. For an n*n image, the algorithm takes O(log n) time on an n*n pyramid.>

The author reviews a number of parallel-processing projects which use processing power, memory and input/output of image data for image analysis. The systems covered include ILLIAC, CLIP, MPP, the cytocomputer, SNAP, and PAPIA and II. Issues in parallelism reviewed include types of parallelism, types of operation, complexity of processing elements, and the different paradigms of human vision and their application and implementation.>

A review of image-processing systems developed until now is given, highlighting the weak points of such systems and the trends that have dictated their evolution through the years producing different generations of machines. Each generation may be characterized by the hardware architecture, the programmability features and the relative application areas. The need for multiprocessing hierarchical systems is discussed, focusing on pyramidal architectures. Their computational paradigms, their virtual and physical implementation, their programming and languages, are discussed.>

In 1981 a national research program for the design, simulation and construction of a multiprocessor image processing system was started. After a first phase devoted to the comparison of suggested and existing systems and to the definition of a set of benchmarks and to the evaluation of the performances of the major classes of machines, a new system has been defined. The structure of the new system is based on a pyramid of processors and many applications in which this machine may be exploited are highlighted. The multiprocessor architecture has been fully designed and the chip will be built by an Italian silicon. foundry, the SGS company, within the framework of the multichip national project.

This paper describes a generic image processing language IPL, and a programming environment supporting the language primitives for an image information system. The central notion of IPL is that it allows the user to navigate through the image database and manipulate images using generalized icons. The image processing language IPL consists of three subsets: the logical image processing language LIPL, the interactive image processing language IIPL, and the physical image processing language PIPL. This paper presents the main concepts of this generic language, some examples, and a scenario.

In picture processing it is often convenient to deal with a stick-like version (skeleton) of binary digital images. Although skeleton connectedness is not necessary for storage and retrieval purposes, this property is desirable when a structural description of images is of interest. In this paper a parallel procedure is described which, applied to a connected image, originates a connected skeleton made by the union of simple digital arcs. The procedure involves a step by step propagation of the background over the image. At every step, contour elements either belonging to the significant convex regions of the current image or being local maxima of the original image are selected as skeleton elements. Since the final set so obtained is not ensured to be connected, the configurations in correspondence of which disconnections appear are investigated and the procedures to avoid this shortcoming are given. The presence of the whole set of local maxima among the skeleton elements ensures the possibility of recovering the original image by means of a reverse distance transform. The details of the program implementing the proposed algorithm on a parallel processor are finally included.

Picture processing includes a variety of algorithms employed at different stages within a recognition process. Although single parallel algorithms have been suggested, no systematic comparison with sequential algorithms is available. We propose here some parallel algorithms solving a selected set of picture-processing tasks and compare their speed, when implemented on a CLIP machine, with that of the equivalent sequential algorithms implemented on a standard minicomputer. It is shown that parallel algorithms are faster than the sequential ones by a factor depending on the size of the digitization matrix, even when arithmetical operations are widely involved.

Theoretical costs on general purpose algorithms have been suggested independently from the machine (computer). On an image processing task a computational cost, based on computing time, is introduced showing a discrepancy between theory and practice due to the dependence on computer architecture and programming language syntax. Furthermore, a quality factor is presented to account for the efficiency of the program coding each algorithm.

This paper reports some results on the use of parallel-structured computers to detect and describe concavities in simply connected planar regions (``domains'' or ``blobs''). We show, in particular, how these concavities may be obtained by a parallel filling-in process-somewhat like pouring liquid into several cups simultaneously. It has been shown that the concavities and concavity tree of a regular cellular blob (i.e., a digitized simply connected planar region) can be obtained by the use of a sequential algorithm that finds the minimum-perimeter polygon (MPP) passing through the boundary cells of the cellular blob. In this paper we show how any such MPP may be computed by a sequence of simultaneous local operations in a parallel-structured computer. We also show that the ratio of computation times for sequential algorithms to those for parallel algorithms operating on the cellular image of a large circular blob is approximately proportional to the square root of the blob's perimeter, assuming the size of the vertex-detecting window is fixed and large enough to detect one or more vertices of the MPP. We also show that filling in the concavities by a sequence of parallel local operations terminates to an approximation of the cellular hull (i.e., the digitization of the convex hull of the original blob) in a finite time, and that this approximation is a subset of the cellular hull.

A computer program has been written to separate overlapping convex blobs present in a binary input picture. The procedure is based on the detection of a feature, concavity, which occurs on the intersecting contours of the overlapping blobs. In order to obtain splitting, paths are grown from these regions of concavity toward the interior until segmentation is achieved. Flow charts of the program and an example are included.