A Self-Organizing Neural System for Learning to Recognize Textured Scenes

A self-organizing ARTEX model is developed to categorize and classify textured image regions. ARTEX specializes the FACADE model of how the visual cortex sees, and the ART model of how temporal and prefrontal cortices interact with the hippocampal system to learn visual recognition categories and their names. FACADE processing generates a vector of boundary and surface properties, notably texture and brightness properties, by utilizing multi-scale filtering, competition, and diffusive filling-in. Its context-sensitive local measures of textured scenes can be used to recognize scenic properties that gradually change across space, as well a.s abrupt texture boundaries. ART incrementally learns recognition categories that classify FACADE output vectors, class names of these categories, and their probabilities. Top-down expectations within ART encode learned prototypes that pay attention to expected visual features. When novel visual information creates a poor match with the best existing category prototype, a memory search selects a new category with which classify the novel data. ARTEX is compared with psychophysical data, and is benchmarked on classification of natural textures and synthetic aperture radar images. It outperforms state-of-the-art systems that use rule-based, backpropagation, and K-nearest neighbor classifiers.Defense Advanced Research Projects Agency; Office of Naval Research (N00014-95-1-0409, N00014-95-1-0657

Technological Claustrophobia

Tim O'Riley discusses the genesis of his project to examine how technology can be used to construct a speculative model of a physical and spatial experience

The State of the Art in Cartograms

Cartograms combine statistical and geographical information in thematic maps, where areas of geographical regions (e.g., countries, states) are scaled in proportion to some statistic (e.g., population, income). Cartograms make it possible to gain insight into patterns and trends in the world around us and have been very popular visualizations for geo-referenced data for over a century. This work surveys cartogram research in visualization, cartography and geometry, covering a broad spectrum of different cartogram types: from the traditional rectangular and table cartograms, to Dorling and diffusion cartograms. A particular focus is the study of the major cartogram dimensions: statistical accuracy, geographical accuracy, and topological accuracy. We review the history of cartograms, describe the algorithms for generating them, and consider task taxonomies. We also review quantitative and qualitative evaluations, and we use these to arrive at design guidelines and research challenges

Digital Documentation of Masada Fortress in Israel: Integrated Methodologies of Survey and Representation

The general aim of the MRP - Masada Research Project is to create a comprehensive digital documentation of the archaeological site of Masada. Integrated 3D digital survey methodologies allowed the acquisition of all the information necessary for the creation of a digital database. This paper describes some results about the interaction between complex sets of data, acquired with various tools, and its dissemination through contemporary representation systems. The research conducted explains how the “migration” of reality in a virtual environment depends strongly on the structure of an efficient workflow and the proper use of available technologies. Digital tools allow the creation of customized and open-ended knowledge systems through which users can interface with the elements of the space around them interactively and be/become more conscious about the archaeological heritage

Investigating the construction methods of an opus vermiculatum mosaic panel

From the third century BC to the second century AD small detailed central panels (emblemata) made using the opus vermiculatum technique were used as focal points in larger mosaic pavements. They were custom made in stone or terracotta trays to facilitate their transport and placement. Although mosaic panels in opus vermiculatum have been discovered throughout the Hellenistic and Roman Mediterranean, the location of the workshops specialising in the production of the finely worked panels is still unclear. Their association with named artists, for example Dioskourides of Samos, and the locations of finds (such as the fragments of the floor by Hephaistion at Pergamon) point to workshops in the eastern Mediterranean. A large unidentified fragment of an emblema, still in its terracotta tray, from the collections of the Department of Greece and Rome in the British Museum was the subject of analytical examination. These investigations of the tesserae (glass cubes), traces of pigments and mortar aimed to determine the raw materials and manufacturing processes for the mosaic and to characterise the nature of the application of paint to the mortar. Egyptian blue pigment and traces of hematite and carbon suggest that a fully coloured drawing was executed on the fresh mortar to guide the positioning of the tesserae. In addition, samples from the terracotta tray were taken in an attempt to identify its provenance. This contribution describes how the results of these investigations have been used to provide a deeper understanding of opus vermiculatum construction methods

Amodal completion in visual working memory

Amodal completion refers to the perceptual “filling-in” of partly occluded object fragments. Previous work has shown that object completion occurs efficiently, at early perceptual stages of processing. However, despite efficient early completion, at a later stage, the maintenance of complete-object representations in visual working memory (VWM) may be severely restricted due to limited mnemonic resources being available. To examine for such a limitation, we investigated whether the structure of to-be-remembered objects influences what is encoded and maintained in VWM using a change detection paradigm. Participants were presented with a memory display that contained either “composite” objects, that is, notched shapes abutting an occluding square, or equivalent unoccluded, “simple” objects. The results showed overall increased memory performance for simple relative to composite objects. Moreover, evidence for completion in VWM was found for composite objects that were interpreted as globally completed wholes, relative to local completions or an uncompleted mosaic (baseline) condition. This global completion advantage was obtained only when the “context” of simple objects also supported a global object interpretation. Finally, with an increase in memory set size, the global object advantage decreased substantially. These findings indicate that processes of amodal completion influence VWM performance until some overall-capacity limitation prevents completion. VWM completion processes do not operate automatically; rather, the representation format is determined top-down based on the simple object context provided. Overall, these findings support the notion of VWM as a capacity-limited resource, with storage capacity depending on the structured representation of to-be-remembered objects

Recording, Documentation, and Information Management for the Conservation of Heritage Places: Guiding Principles

Provides guidance on integrating recording, documentation, and information management of territories, sites, groups of buildings, or monuments into the conservation process; evaluating proposals; consulting specialists; and controlling implementation