Ryutarou Ohbuchi

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In this paper, we describe a shape-based 3D model retrieval method based on multi-scale local visual features. The features are extracted from 2D range images of the model viewed from uniformly sampled locations on a view sphere. The method is appearance-based, and accepts all the models that can be rendered as a range image. For each range image, a set of(More)
This paper presents a robust watermarking algorithm with informed detection for 3D polygonal meshes. The algorithm is based on our previous algorithm [22] that employs mesh-spectral analysis to modify mesh shapes in their transformed domain. This paper presents extensions to our previous algorithm so that (1) much larger meshes can be watermarked within a(More)
We describe initial results which show “live” ultrasound echography data visualized within a pregnant human subject. The visualization is achieved by using a small video camera mounted in front of a conventional head-mounted display worn by an observer. The camera’s video images are composited with computer-generated ones that contain one or more 2D(More)
This paper discusses techniques for embedding data into three-dimensional (3D) polygonal models of geometry. Given objects consisting of points, lines, (connected) polygons, or curved surfaces, the algorithms described in this paper produce polygonal models with data embedded into either their vertex coordinates, their vertex topology (connectivity), or(More)
Digital watermarking embeds a structure called watermark into the target data, such as image and 3D polygonal models. The watermark can be used, for example, to enforce copyright and to detect tampering. This paper presents a new robust watermarking method that adds watermark into a 3D polygonal mesh in the mesh’s spectral domain. The algorithm computes(More)
In this paper, we propose a pair of shape features for shape-similarity search of 3D polygonal-mesh models. The shape features are extension of the D2 shape functions proposed by Osada et al. [Osada01, Osada02]. Our proposed shape features are tolerant of topological variations and geometrical degeneracies. Our shape feature is also invariant to similarity(More)
Non-rigid 3D shape retrieval has become an important research direction in content-based 3D object retrieval. The aim of this track is to measure and compare the performance of non-rigid 3D shape retrieval methods implemented by different participants around the world. The track is based on a new non-rigid 3D shape benchmark, which contains 600 watertight(More)
This paper describes a 3D shape model retrieval method that accepts, as a query, a 3D mesh obtained by a range scan from a viewpoint. The proposed method visually compares single depth map of the query with depth maps of a 3D model rendered from multiple viewpoints. Comparison of the depth maps employs bag-of local visual features extracted by using a(More)
Our previous shape-based 3D model retrieval algorithm compares 3D shapes by using thousands of local visual features per model. A 3D model is rendered into a set of depth images, and from each image, local visual features are extracted by using the <i>Scale Invariant Feature Transform</i> (SIFT) algorithm by Lowe. To efficiently compare among large sets of(More)