Patrick Brigger

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We present a novel formulation for B-spline snakes that can be used as a tool for fast and intuitive contour outlining. We start with a theoretical argument in favor of splines in the traditional formulation by showing that the optimal, curvature-constrained snake is a cubic spline, irrespective of the form of the external energy field. Unfortunately, such(More)
This paper deals with the use of some morphological tools for image and video coding. Mathematical morphology can be considered as a shape-oriented approach to signal processing, and some of its features make it very useful for compression. Rather than describing a coding algorithm, the purpose of this paper is to describe some morphological tools that have(More)
Attenuation correction is essential to PET imaging but often requires impractical acquisition times. Segmentation of short noisier transmission scans has been proposed as a solution. We report that a 3D morphological tool the watershed algorithm is well adapted for segmenting even 2minute PET transmission images. The technique is noniterative, fast, and(More)
1 This work was mainly performed while employed with the Bioengineering and Physical Science Program, BEPS/ORS, National Institutes of Health (NIH), Bethesda, MD, USA. Abstract We present a novel formulation for B-spline snakes that can be used as a tool for fast and intuitive contour outlining. The theory is implemented in a platform independent JAVA(More)
Quadtree-like pyramids have the advantage of re-suiting in a multiresolution representation where each pyramid node has four unambiguous parents. Such a centered topology guarantees a clearly defined up-projection of labels. This concept has been successfully and extensively used in applications of contour detection, object recognition and segmentation.(More)
We consider the construction of least squares pyramids using shifted polynomial spline basis functions. We derive the pre and postfilters as a function of the degree n and the shift parameter . We show that the underlying projection operator is entirely specified by two transfer functions acting on the even and odd signal samples, respectively. We introduce(More)
BACKGROUND We describe a set of image processing algorithms and mathematical models that can be advantageously used in schemes for the segmentation of thallium-201-single photon emission computed tomography (SPECT) images and for computation of left ventricular ejection fraction (EF). METHODS The system consists of two independent blocs for image(More)
Region-based coding schemes are among the most promising compression techniques for very low bit-rate applications. They consist of image segmentation, contour and texture coding. This paper deals with the use of the geodesic skeleton as a morphological tool for contour coding of segmented image sequences. In the geodesic case, already coded and known(More)