Anthony Ashbrook

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The paper proposes a reliable method for estimating quadric surfaces from 3D range data in the framework of object recognition and localization or reverse engineering. Instead of estimating a quadric surface in isolation, the approach ts all the surfaces captured in the scene together taking into account the geometric relationships between them and their(More)
The recognition of shapes in images using Pairwise Geometric His-tograms has previously been confined to fixed scale shape. Although the geometric representation used in this algorithm is not scale invariant , the stable behaviour of the similarity metric as shapes are scaled enables the method to be extended to the recognition of shapes over a range of(More)
This paper deals with the constrained reconstruction of 3D geometric models of objects from range data. It describes a new technique of global shape improvement based upon feature positions and geometric constraints. It suggests a general incre-mental framework whereby constraints can be added and integrated in the model reconstruction process, resulting in(More)
Pairwise geometric histograms have been demonstrated as an eeective descriptor of arbitrary 2-dimensional shape which enable robust and eecient object recognition in complex scenes. In this paper we describe how the approach can be extended to allow the representation and classiication of arbitrary 2 1 2-and 3-dimensional surface shape. This novel(More)
In this paper we show how the cost of a structured light, range nding system can be substantially reduced by visually tracking the structured light source. To be able to recover range measurements using a structured light range nder the relative positions of the struc-tured light source and light sensor must be known. This is typically achieved by carefully(More)
While the problem of model tting for 3-dimensional range data has been addressed with some success, the problem of increasing the accuracy of the whole t still remains. This paper describes a technique of global shape improvement based upon feature position and shape constraints. These constraints may be globally applied or inferred from general engineering(More)
This paper deals with the reconstruction of 3D geometric shapes based on observed noisy 3D measurements and multiple coupled non-linear shape constraints. Here a shape could be a complete object, a portion of an object, a part of a building etc. The paper suggests a general incremental framework whereby constraints can be added and integrated in the model(More)
The paper proposes a reliable method for estimating quadric surfaces from 3D range data in the framework of object recognition and localization or object modelling. Instead of estimating a quadric surface individually the approach fits all the surfaces captured in the scene together taking into account the geometric relationships between them and their(More)
In this paper we consider one aspect of the problem of automatically building shape models of articulating objects from example range images. Central to the model construction problem is the registration of range data, taken from different vantage points, into a common coordinate frame. This involves determining a transformation for each set of range data(More)
In this paper we present an algorithm for automatically building models of articulated objects from range data. These models not only describe the surface shape of the object but also describe the kinematics that constrain the movement of one object component in relation to another. This is more diicult than building models of rigid objects because the(More)