Browsing by Author "Lin, HYS"

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3-D shape retrieval using cognitive psychology-based principles
(2005)
Lin, HYS
;
Lin, JC
;
Liao, HYM
;
資訊工程學系
;
Department of Computer Science
In this paper, we incorporate a set of principles that originated in cognitive psychology into tire design of 3-D drape analysis and retrieval systems. Based on the "visual salience-guided mesh decomposition "scheme we proposed previously, a 3-D shape represented in mesh form is first broken into parts such that human visual perception of the parts can be appropriately mimicked. Next, tire decomposed parts are individually analyzed and quantified according to the properties of visual salience. To establish the indices of 3-D meshes, for the subsequent retrieval process, spherical parameterization is adopted to map the decomposed parts onto the surface of a unit sphere. In this way, the degree of similarity between a query provided by a user and models in the database call be calculated. The experiment results show that the retrieval performance of the proposed scheme is indeed efficient and powerful.
A cognitive psychology-based approach for 3-D shape retrieval
(2005)
Lin, HYS
;
Liao, HYM
;
Lin, JC
;
資訊工程學系
;
Department of Computer Science
In this paper, we incorporate a set of principles originated from cognitive psychology into the design of 3-D shape analysis and retrieval algorithms. Based on the "visual salience-guided mesh decomposition" we previously proposed, a 3-D mesh-based shape is first broken up into parts such that human visual perception on parts can be appropriately mimicked. Next, the decomposed parts are individually analyzed and quantified according to the properties of visual salience. To establish the indices of 3-D meshes for shape matching, spherical parameterization is adopted to map the decomposed parts onto the surface of a unit sphere. In this way, the dissimilarity degree between the query acquired from users and a model in database can be calculated. The experimental results have shown that the matching performance of the proposed scheme is indeed efficient and powerful.
Fragile watermarking for authenticating 3-D polygonal meshes
(2005-12-01)
Lin, HYS
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Liao, HYM
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Lu, CS
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Lin, JC
;
資訊工程學系
Designing a powerful fragile watermarking technique for authenticating three-dimensional (3-D) polygonal meshes is a very difficult task. Yeo and Yeung [34] were first to propose a fragile watermarking method to perform authentication of 3-D polygonal meshes. Although their method can authenticate the integrity of 3-D polygonal meshes, it cannot be used for localization of changes. In addition, it is unable to distinguish malicious attacks from incidental data processings. In this paper, we trade off the causality problem in Yen and Yeung's method for a new fragile watermarking scheme. The proposed scheme can not only achieve localization of malicious modifications in visual inspection, but also is immune to certain incidental data processings (such as quantization of vertex coordinates and vertex reordering). During the process of watermark embedding, a local mesh parameterization approach is employed to perturb the coordinates of invalid vertices while cautiously maintaining the visual appearance of the original model. Since the proposed embedding method is independent of the order of vertices, the hidden watermark is immune to some attacks, such as vertex reordering. In addition, the proposed method can be used to perform region-based tampering detection. The experimental results have shown that the proposed fragile watermarking scheme is indeed powerful.
Visual salience-guided mesh decomposition
(2004)
Lin, HYS
;
Liao, HYM
;
Lin, JC
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a novel mesh decomposition scheme called "visual salience-guided mesh decomposition". The concept of part salience is originated from cognitive psychology and it asserts the salience of a part can be determined by (at least) three factors: the protrusion, the boundary strength, and the relative size of a part. We try to convert these "conceptual" rules into "real'' computational processes and then use them to "guide" a 3D mesh decomposition process. The experimental results have shown that the proposed scheme is indeed effective and powerful in decomposing a 3D mesh into significant components.