William J. Fitzgerald

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Bright and dark flashes are typical artifacts in degraded motion picture material. The distortion is referred to as "dirt and sparkle" in the motion picture industry. This is caused either by dirt becoming attached to the frames of the film, or by the film material being abraded. The visual result is random patches of the frames having grey level values(More)
—We propose some Bayesian methods to address the problem of fitting a signal modeled by a sequence of piecewise constant linear (in the parameters) regression models, for example, autoregressive or Volterra models. A joint prior distribution is set up over the number of the changepoints/knots, their positions, and over the orders of the linear regression(More)
The core/periphery structure is ubiquitous in network studies. The discrete version of the concept is that individuals in a group belong to either the core, which has a high density of ties, or to the periphery, which has a low density of ties. The density of ties between the core and the periphery may be either high or low. If the core/periphery structure(More)
This paper presents a number of model based interpolation schemes tailored to the problem of interpolating missing regions in image sequences. These missing regions may be of arbitrary size and of random, but known, location. This problem occurs regularly with archived film material. The film is abraded or obscured in patches, giving rise to bright and dark(More)
In some important applications such as speaker recognition or image texture classification, the data to be processed are sets of vectors. As opposed to standard settings where the data are individual vectors, it is difficult to design a reliable kernel between sets of vectors of possibly different cardinality. In this paper, we build kernels between sets of(More)
We propose a content based image retrieval system based on object extraction through image segmentation. A general and powerful multiscale segmentation algorithm automates the segmentation process, the output of which is assigned novel colour and texture descriptors which are both efficient and effective. Query strategies consisting of a semi-automated and(More)
Four preservice teachers' online discussion groups of eight randomly assigned participants each were studied to analyze the contribution of individual and social factors in the development of communication networks. Participants shared observations and follow-up responses in five weekly rounds of data collection. Using a core-periphery social network(More)
We address the problem of detecting, and subsequently removing, `line scratch' distortion in motion picture frames (see gure 4). A model for the lines' interaction with the imm age data is constructed. A sampling based algorithm based on the Reversible Jump Markov chain Monte Carlo framee work is developed which enables automatic determination of both the(More)