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Author

Wai-Man Pang

Bio: Wai-Man Pang is an academic researcher from Caritas Institute of Higher Education. The author has contributed to research in topics: Rendering (computer graphics) & CUDA. The author has an hindex of 17, co-authored 65 publications receiving 870 citations. Previous affiliations of Wai-Man Pang include University of Aizu & The Chinese University of Hong Kong.


Papers
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Journal ArticleDOI
01 Aug 2008
TL;DR: An optimization-based halftoning technique that preserves the structure and tone similarities between the original and the halftone images and possesses the blue-noise property and does not introduce annoying patterns.
Abstract: This paper presents an optimization-based halftoning technique that preserves the structure and tone similarities between the original and the halftone images. By optimizing an objective function consisting of both the structure and the tone metrics, the generated halftone images preserve visually sensitive texture details as well as the local tone. It possesses the blue-noise property and does not introduce annoying patterns. Unlike the existing edge-enhancement halftoning, the proposed method does not suffer from the deficiencies of edge detector. Our method is tested on various types of images. In multiple experiments and the user study, our method consistently obtains the best scores among all tested methods.

100 citations

Journal ArticleDOI
TL;DR: This paper takes advantage of the piecewise consistent property of the two normal fields of a mesh surface and proposes an effective framework in which they are filtered and integrated using a novel method to guide the denoising process.
Abstract: Most mesh denoising techniques utilize only either the facet normal field or the vertex normal field of a mesh surface. The two normal fields, though contain some redundant geometry information of the same model, can provide additional information that the other field lacks. Thus, considering only one normal field is likely to overlook some geometric features. In this paper, we take advantage of the piecewise consistent property of the two normal fields and propose an effective framework in which they are filtered and integrated using a novel method to guide the denoising process. Our key observation is that, decomposing the inconsistent field at challenging regions into multiple piecewise consistent fields makes the two fields complementary to each other and produces better results. Our approach consists of three steps: vertex classification , bi-normal filtering , and vertex position update . The classification step allows us to filter the two fields on a piecewise smooth surface rather than a surface that is smooth everywhere. Based on the piecewise consistence of the two normal fields, we filtered them using a piecewise smooth region clustering strategy. To benefit from the bi-normal filtering, we design a quadratic optimization algorithm for vertex position update. Experimental results on synthetic and real data show that our algorithm achieves higher quality results than current approaches on surfaces with multifarious geometric features and irregular surface sampling.

85 citations

Journal ArticleDOI
TL;DR: A serious game focuses on teaching trainees blood management skills, which are critical for safe operations, and integrates game elements, including task-oriented and time-attack scenarios, bonuses, game levels, and performance evaluation tools.
Abstract: Orthopedic surgery treats the musculoskeletal system, in which bleeding is common and can be fatal. To help train future surgeons in this complex practice, researchers designed and implemented a serious game for learning orthopedic surgery. The game focuses on teaching trainees blood management skills, which are critical for safe operations. Using state-of-the-art graphics technologies, the game provides an interactive and realistic virtual environment. It also integrates game elements, including task-oriented and time-attack scenarios, bonuses, game levels, and performance evaluation tools. To study the system's effect, the researchers conducted experiments on player completion time and off-target contacts to test their learning of psychomotor skills in blood management.

67 citations

Journal ArticleDOI
TL;DR: This work votes on surface normal tensors from robust statistics to guide the creation of consistent subneighborhoods subsequently used by moving least squares (MLS) to give a unified mesh-denoising framework for not only handling noise but also enabling the recovering of surfaces with both sharp and small-scale features.
Abstract: Mesh denoising is imperative for improving imperfect surfaces acquired by scanning devices The main challenge is to faithfully retain geometric features and avoid introducing additional artifacts when removing noise Unlike the existing mesh denoising techniques that focus only on either the first-order features or high-order differential properties, our approach exploits the synergy when facet normals and quadric surfaces are integrated to recover a piecewise smooth surface In specific, we vote on surface normal tensors from robust statistics to guide the creation of consistent subneighborhoods subsequently used by moving least squares (MLS) This voting naturally leads to a conceptually simple way that gives a unified mesh-denoising framework for not only handling noise but also enabling the recovering of surfaces with both sharp and small-scale features The effectiveness of our framework stems from: 1) the multiscale tensor voting that avoids the influence from noise; 2) the effective energy minimization strategy to searching the consistent subneighborhoods; and 3) the piecewise MLS that fully prevents the side effects from different subneighborhoods during surface fitting Our framework is direct, practical, and easy to understand Comparisons with the state-of-the-art methods demonstrate its outstanding performance on feature preservation and artifact suppression

63 citations

Journal ArticleDOI
TL;DR: This paper investigates the effect of using object-oriented movements in a virtual environment as visual guidance on the modulation of sensorimotor EEG rhythms generated by hand MI and proposes an algorithm to automatically extract subject-specific optimal frequency and time bands for the discrimination of ERD patterns produced by left and right hand MI.

52 citations


Cited by
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Journal ArticleDOI
TL;DR: A manga-specific image retrieval system that consists of efficient margin labeling, edge orientation histogram feature description with screen tone removal, and approximate nearest-neighbor search using product quantization is proposed.
Abstract: Manga (Japanese comics) are popular worldwide. However, current e-manga archives offer very limited search support, i.e., keyword-based search by title or author. To make the manga search experience more intuitive, efficient, and enjoyable, we propose a manga-specific image retrieval system. The proposed system consists of efficient margin labeling, edge orientation histogram feature description with screen tone removal, and approximate nearest-neighbor search using product quantization. For querying, the system provides a sketch-based interface. Based on the interface, two interactive reranking schemes are presented: relevance feedback and query retouch. For evaluation, we built a novel dataset of manga images, Manga109, which consists of 109 comic books of 21,142 pages drawn by professional manga artists. To the best of our knowledge, Manga109 is currently the biggest dataset of manga images available for research. Experimental results showed that the proposed framework is efficient and scalable (70 ms from 21,142 pages using a single computer with 204 MB RAM).

625 citations

Journal ArticleDOI
TL;DR: This review presents the past and present work on GPU accelerated medical image processing, and is meant to serve as an overview and introduction to existing GPU implementations.

360 citations

Journal ArticleDOI
01 Jan 2018
TL;DR: A systematic review of 233 separate findings identified from 152 studies that investigate the factors (i.e., immersive qualities, contextual differences, and individual psychological traits) that predict social presence is offered.
Abstract: Social presence, or the feeling of being there with a “real” person, is a crucial component of interactions that take place in virtual reality. This paper reviews the concept, antecedents, and implications of social presence, with a focus on the literature regarding the predictors of social presence. The article begins by exploring the concept of social presence, distinguishing it from two other dimensions of presence—telepresence and self-presence. After establishing the definition of social presence, the article offers a systematic review of 222 separate findings identified from 150 studies that investigate the factors (i.e., immersive qualities, contextual differences, and individual psychological traits) that predict social presence. Finally, the paper discusses the implications of heightened social presence and when it does and does not enhance one’s experience in a virtual environment.

348 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarize the motivations behind utilizing the smoothed particle hydrodynamics (SPH) method in an industrial context, as well as deriving general conclusions regarding its assets and limitations and stressing the remaining challenges in order to make it an hand-on computational tool.

296 citations