Image Access, the Semantic Gap, and Social Tagging as a Paradigm Shift
Corinne Jörgensen · Advances in Classification Research Online · 2007
The recent phenomenon of "social tagging" or "distributed indexing" raises a number of questions regarding long-held beliefs and practices of the classification and indexing community.This workshop paper covers several of these issues, such as locus of authority, control, and meaning, and suggests we may be observing the emergence of a new paradigm of knowledge organization. The Semantic GapThe "semantic gap" is mentioned frequently in the literature of image access.The term originated in computer science (Smeulders et al., 2000) and is still used in the CS literature today to refer to the difference between two descriptions of an object using different languages, specifically the difference between a human-readable description and a computational representation.In a computational representation, a simple image of an object moves from the level of individual pixels to assemblages of image primitives such as color, shape/region, and texture, to the assemblage and recognition of an object, at least at the level of a simple "basic object."Object recognition necessitates a level of "understanding" of what is being represented; this is achieved by inferring what different combinations of primitives may represent, e.g.black spots or black stripes on an orangetan background and an assemblage of potential "leg," "body," "tail," and "head" shapes, perhaps combined with "nature colors," could be interpreted as a leopard or tiger.The process is fraught with stumbling blocks such as occlusion, angle of view, scale, shadow, and lack of uniqueness, to mention a few.Jorgensen, C. (2007).Image access, the semantic gap, and social tagging as a paradigm shift.