Shape Representation Using Concavity Graphs
نویسندگان
چکیده
In this paper, a new graph data structure for 2-D shape representation is proposed. The new structure is called a concavity graph, and is an evolution from the already known “concavity tree”. Even though a concavity graph bears a fundamental resemblance to a concavity tree, the former is able to describe the shape of multiple objects in an image and their spatial configuration, and is hence inherently more complex. The aim of concavity graphs is two-fold: first we want to analyze the patterns in a multi-object image in a way that will (1) provide better representation of their shapes, and (2) convey useful information about how they “interact” together. Second, we want our analysis technique to facilitate similarity matching between two images. This paper introduces the new structure and outlines how it can be used for shape representation as well as similarity matching.
منابع مشابه
Hierarchical representation of 2-D shapes using convex polygons: a contour-based approach
A concavity tree is a data structure for hierarchically representing the shape of two-dimensional silhouettes using convex polygons. In this paper, we present a new algorithm for concavity tree extraction. The algorithm is fast, works directly on the pixel grid of the shape, and uses exact convex hull computations. We compare our method to the morphological approach to concavity tree extraction...
متن کاملCompressing 2-D Shapes Using Concavity Trees
Concavity trees have been known for quite some time as structural descriptors of 2-D shape; however, they haven’t been explored further until recently. This paper shows how 2-D shapes can be concisely, but reversibly, represented during concavity tree extraction. The representation can be exact, or approximate to a pre-set degree. This is equivalent to a lossless, or lossy compression of the im...
متن کاملBalancedness and Concavity of Fractional Domination Games
In this paper, we introduce a fractional domination game arising from fractional domination problems on graphs and focus on its balancedness and concavity. We first characterize the core of the fractional domination game and show that its core is always non-empty taking use of dual theory of linear programming. Furthermore we study concavity of this game.
متن کاملModel based foot shape classification using 2D foot outlines
This study introduces a novel technique to identify foot outline characteristics and to classify feet into groups using turning functions and clustering techniques so that shape can complement anthropometry in producing good fitting shoes. The digital 3D foot scans, obtained from 50 Hong Kong Chinese subjects (25males and 25 females)were processed to generate the foot outlines at heights of 2mm...
متن کاملDetection of change in shape: an advantage for concavities.
Shape representation was studied using a change detection task. Observers viewed two individual shapes in succession, either identical or one a slightly altered version of the other, and reported whether they detected a change. We found a dramatic advantage for concave compared to convex changes of equal magnitude. Observers were more accurate when a concavity along the contour was introduced, ...
متن کامل