Ontology Learning in Multimedia Information Extraction from Product Catalogues

We propose a methodology for extracting multimedia information from product catalogues empowered by the synergetic use and extension of a domain ontology. The use of domain ontologies in this context additionally opens up innovative ways of catalogue use. The method is characterized by incrementally feeding and exploiting the ontology during an information extraction process, implemented by the semantic annotation of the analysed document, and by providing support for detecting existing similar ontologies to enable reuse of (parts of) them

The natural center of chromaticity space is not always achromatic: A new look at color induction

Although current theories of color vision differ in many respects, they all assume the existence of a uniquely defined neutral point in chromaticity space. It generally is assumed that this point satisfies several criteria simultaneously. One of these criteria is that it is perceived as achromatic. A further criterion shared by most theories is the structural assumption that lines in chromaticity space of constant hue converge on the neutral point. The basic assumption that these two criteria coincide is clearly true for isolated spots of light presented in darkness, and it usually is taken for granted that this coincidence generalizes to more complex visual stimuli. Here, we show that this is not the case. Our experiments with infields in chromatic surrounds revealed that the point in chromaticity space that appears gray is clearly different from the point on which lines of constant hue converge. A plausible interpretation of this apparently paradoxical finding in terms of color scission is proposed