Browsing by Author "Tsai, Ming-Han"

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Adaptive Motion Data Representation with Repeated Motion Analysis
(2011-04-01)
Lin, I-Chen
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Peng, Jen-Yu
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Lin, Chao-Chih
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Tsai, Ming-Han
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資訊工程學系
In this paper, we present a representation method for motion capture data by exploiting the nearly repeated characteristics and spatiotemporal coherence in human motion. We extract similar motion clips of variable lengths or speeds across the database. Since the coding costs between these matched clips are small, we propose the repeated motion analysis to extract the referred and repeated clip pairs with maximum compression gains. For further utilization of motion coherence, we approximate the subspace-projected clip motions or residuals by interpolated functions with range-aware adaptive quantization. Our experiments demonstrate that the proposed feature-aware method is of high computational efficiency. Furthermore, it also provides substantial compression gains with comparable reconstruction and perceptual errors.
Augmented Reality Instruction for Object Assembly based on Markerless Tracking
(2016)
Wu, Li-Chen
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Lin, I-Chen
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Tsai, Ming-Han
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交大名義發表
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National Chiao Tung University
Conventional object assembly instructions are usually written or illustrated in a paper manual. Users have to associate these static instructions with real objects in 3D space. In this paper, a novel augmented reality system is presented for a user to interact with objects and instructions. While most related methods pasted obvious markers onto objects for tracking and constrained their orientations or shapes, we adopt a markerless strategy for more intuitive interaction. Based on live information from an off-the-shelf RGB-D camera, the proposed tracking procedure identifies components in a scene, tracks their 3D positions and orientations, and evaluates whether there are combinations of components. According to the detected events and poses, our indication procedure then dynamically displays indication lines, circular arrows and other hints to guide a user to manipulate the components into correct poses. The experiment shows that the proposed system can robustly track the components and respond intuitive instructions at an interactive rate. Most of users in evaluation are interested and willing to use this novel technique for object assembly.
Design and Initial Evaluation of a VR based Immersive and Interactive Architectural Design Discussion System
(2020-01-01)
Hsu, Ting-Wei
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Tsai, Ming-Han
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Babu, Sabarish, V
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Hsu, Pei-Hsien
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Chang, Hsuan-Ming
Design discussion is a very important course in architecture education. In this paper, we developed a VR based architecture design discussion system that allows members to visualize and discuss the architectural models and to modify the models during discussion. Since the system is designed to work on top of Rhinoceros and Grasshopper, the object database is updated right after the object modification. Members communicate via voice, object manipulations, and mid-air sketching as well as on-surface sketching in the virtual environment. Several tools have been designed to enhance the sense of presence and to make the discussion more effective. We also developed a rollback mechanism to help users intuitively and quickly revert to a previous state of discussion to make some changes or to start a new direction of discussion. To evaluate the system, we conducted an initial user study with 14 participants to assess the user experience, user impression and effectiveness of the system. The feedback from participants were positive and suggested that the system could be effective and useful for supporting architecture design discussion.
Human face aging with guided prediction and detail synthesis
(2014-09-01)
Tsai, Ming-Han
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Liao, Yen-Kai
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Lin, I-Chen
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資訊工程學系
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Department of Computer Science
In this paper, we present an example-based method to estimate the aging process of a human face. To tackle the difficulty of collecting considerable chronological photos of individuals, we utilize a two-layer strategy. Based on a sparse aging database, an EM-PCA-based algorithm with the personal guidance vector is first applied to conjecture the temporal variations of a target face. Since the subspace-based prediction may not preserve detailed creases, we propose synthesizing facial details with a separate texture dataset. Besides automatic simulation, the proposed framework can also include further guidance, e.g., parents\' impact vector or users\' indication of wrinkles. Our estimated results can improve feature point positions and user evaluation demonstrates that the two-layer approach provides more reasonable aging prediction.
Immersive VR Environment for Architectural Design Education
(2017-01-01)
Tsou, Chia-Hung
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Hsu, Ting-Wei
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Lin, Chun-Heng
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Tsai, Ming-Han
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Hsu, Pei-Hsien
In tradition architectural design education, instructor and students share and discuss their ideas through drawings and models. Physical models are hard to be modified during discussion, and it is difficult to view the interior spaces. Drawings, including plans, elevations and sections, are generally used as a medium for the purpose of presentation and discussion. We propose an integrated system to support architectural design education, in which multiple users can not only explore and discuss 3D designs in a VR environment, but also manipulate 3D elements. This system also integrates procedural 3D modeling, providing users with the capability of modifying 3D designs in real-time through adjustments of parameters.
REAL-TIME UPPER BODY POSE ESTIMATION FROM DEPTH IMAGES
(2015)
Tsai, Ming-Han
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Chen, Kuan-Hua
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Lin, I-Chen
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交大名義發表
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National Chiao Tung University
Estimating upper body poses from a sequence of depth images is a challenging problem. Lately, the state-of-art work adopted a randomized forest method to label human parts in real time. However, it requires enormous training data to obtain favorable results. In this paper, we propose using a novel two-stage method to estimate the probability maps of upper body parts of users. These maps are then used to evaluate the region fitness of body parts for pose recovery. Experiments show that the proposed method can obtain satisfactory outcome in real time and it requires a moderate size of training data.
Skeleton-driven surface deformation through lattices for real-time character animation
(2013-04-01)
Chen, Cheng-Hao
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Tsai, Ming-Han
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Lin, I-Chen
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Lu, Pin-Hua
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資訊工程學系
In this paper, an efficient deformation framework is presented for skeleton-driven polygonal characters. Standard solutions, such as linear blend skinning, focus on primary deformations and require intensive user adjustment. We propose constructing a lattice of cubic cells embracing the input surface mesh. Based on the lattice, our system automatically propagates smooth skinning weights from bones to drive the surface primary deformation, and it rectifies the over-compressed regions by volume preservation. The secondary deformation is, in the meanwhile, generated by the lattice shape matching with dynamic particles. The proposed framework can generate both low- and high-frequency surface motions such as muscle deformation and vibrations with few user interventions. Our results demonstrate that the proposed lattice-based method is liable to GPU computation, and it is adequate to real-time character animation.
VR Lighting Design
(2017-01-01)
Lee, Chi-Yang
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Chang, Hsuan-Ming
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Lin, Chun-Heng
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Tsai, Ming-Han
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Lin, Wen-Chieh
Lighting design is a crucial process in video games, animation, interior design, and some other fields. Current lighting design systems support only direct lighting paradigm which requires fine-tuning each light's parameters to achieve a global lighting effect. In this study, we developed an integrated lighting design system which comprises direct, indirect, and inverse lighting design paradigms in VR enviromnent. The system provides designers with an immersive, intuitive, and effective way of lighting design.