Retrieving Shapes Efficiently by a Qualitative Shape Descriptor: The Scope Histogram

Abstract

Abstract. Efficient image retrieval from large image databases is a challenging problem. In this paper we present a method offering constant time complexity for the comparison of two shapes. In order to achieve this, we extend the qualitative concept of positional-contrast by 86 new relations describing the position of a polygon w. r. t. its line segments. On this basis a histogram of the relations' frequencies is computed for each shape. A useful property of our approach is that, due to the underlying concept of positional-contrast, it can be intuitively decided whether its combination with other features is promising. Especially, retrieval results of about 64% are achieved in the MPEG test with constant time complexity.

A compact shape representation for linear geographical objects

“…In Sect. 3 we introduce our modified definition of scope histograms and compare it to the original one of [15]. Subsequently, we evaluate our modification using the MPEG test in Sect.…”

“…Nevertheless, the representation of shape information still remains an open issue to some extent. In order to address this issue we investigate the application of an approach that has recently been introduced in the context of shape-based image retrieval of two-dimensional silhouettes: the scope histogram [15].…”

Measures of similarity between qualitative descriptions of shape, colour and size applied to mosaic assembling

“…Other approaches for qualitative shape comparison can be classified as calculating a similarity measure: (i) between qualitative descriptions based on bipartite arrangements for matching partial or total contours [21]; (ii) based on conceptual neighbourhood diagrams for comparing qualitative shape descriptions [22]; (iii) based on matrices of qualitative concepts for comparing polygons [23]; (iv) based on scope histograms for comparing polygons described qualitatively [24].…”

Measures of Similarity Between Objects Based on Qualitative Shape Descriptions

“…In the literature works can be found that define similarity measures between shapes that are represented by: (i) quantitative information (Super, 2004;Ling and Jacobs, 2007;Attalla and Siy, 2005;Bai et al, 2008;Gdalyahu and Weinshall, 1998;Mori et al, 2001); (ii) mixed quantitative and qualitative information (Shokoufandeh et al, 2002;Berretti et al, 2000;Siddiqi et al, 1998;Macrini et al, 2008;Sebastian et al, 2001Sebastian et al, , 2002 and (iii) qualitative information (Gottfried, 2008;Kuijpers et al, 2006;Schuldt et al, 2006).…”

“…• based on qualitative shape descriptors: (i) bipartite arrangements defined by Gottfried (2008) that relate line segments of a contour of an object to other parts of that same contour and then a similarity measure between these qualitative descriptions of shape is given; (ii) matrices of qualitative concepts developed by Kuijpers et al (2006) using the double-cross orientation model by Freksa (1992) to describe polylines and to find a similarity measure between polygons; and finally, (iii) polygons are described qualitatively by their scope (calculated as their relative position with respect to one of their line segments where the double-cross grid described by Freksa (1992) is located) and scope histograms generated and used for shape comparing by Schuldt et al (2006).…”