Jun-ichiro Toriwaki

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Al~traet--In this paper, we propose a new method to obtain the Euclidean distance transformation and the Voronoi diagram based on the exact Euclidean metric for an n-dimensional picture. We present four algorithms to perform the transformation which are constructed by the serial composition of n-dimensional filters. When performed by a general purpose(More)
This paper describes a method for the automated anatomical labeling of the bronchial branch extracted from a three-dimensional (3-D) chest X-ray CT image and its application to a virtual bronchoscopy system (VBS). Automated anatomical labeling is necessary for implementing an advanced computer-aided diagnosis system of 3-D medical images. This method(More)
This paper describes a method for tracking the camera motion of a flexible endoscope, in particular a bronchoscope, using epipolar geometry analysis and intensity-based image registration. The method proposed here does not use a positional sensor attached to the endoscope. Instead, it tracks camera motion using real endoscopic (RE) video images obtained at(More)
In this papel; we present a procedure to extract bronchus area from three dimensional chest X-ray CT images. Extraction of bronchus from chest X-ray CT images is of critical importance for both the computer aided detection of lung cancel; and the virutualized bronchoscopy system. This procedure consists of three major steps : (a) calculation of a start(More)
This paper presents new image similarity measure for bronchoscope tracking based on image registration between real and virtual endoscopic images. A function for bronchoscope tracking is one of the fundamental functions in a bronchoscope navigation system. Since it is difficult to attach a positional sensor at the tip of the bronchoscope due to the space(More)
A virtual manipulation system for origami (paper folding) is described. A piece of paper defined in a computer can be deformed interactively by picking and moving a corner vertex of a paper face on a graphic screen using a mouse. Three kinds of folding operations and a curving operation transform the paper into a three-dimensional figure made of flat or(More)
In this paper we present a procedure which automatically extracts soft-tissue from multi-sliced head MRI images, and then displays three-dimensional shapes of the extracted soft-tissues. We use an iterative thresholding algorithm for segmentation in which an optimum threshold value is decided based on a goodness measure we proposed. This procedure can be(More)