Parametric editing of clothed 3D avatars

Easy editing of a clothed 3D human avatar is central to many practical applications. However, it is easy to produce implausible, unnatural looking results, since subtle reshaping or pose alteration of avatars requires global consistency and agreement with human anatomy. Here, we present a parametric editing system for a clothed human body, based on use of a revised SCAPE model. We show that the parameters of the model can be estimated directly from a clothed avatar, and that it can be used as a basis for realistic, real-time editing of the clothed avatar mesh via a novel 3D body-aware warping scheme. The avatar can be easily controlled by a few semantically meaningful parameters, 12 biometric attributes controlling body shape, and 17 bones controlling pose. Our experiments demonstrate that our system can interactively produce visually pleasing results.     

Enriching one-class collaborative filtering with content information from social media

In recent years, recommender systems have become popular to handle the information overload problem of social media websites. The most widely used Collaborative Filtering methods make recommendations by mining users’ rating history. However, users’ behaviors in social media are usually implicit, where no ratings are available. This is a One-Class Collaborative Filtering (OCCF) problem with only positive examples. How to distinguish the negative examples from missing data is important for OCCF. Existing OCCF methods tackle this by the statistical properties of users’ historical behavior; however, they ignored the rich content information in social media websites, which provide additional evidence for profiling users and items. In this paper, we propose to improve OCCF accuracy by exploiting the social media content information to find the potential negative examples from the missing user-item pairs. Specifically, we get a content topic feature for each user and item by probabilistic topic modeling and embed them into the Matrix Factorization model. Extensive experiments show that our algorithm can achieve better performance than the state-of-art methods.     

A robust projector–camera interactive display system based on finger touch control by fusing finger and its shadow

A robust projector–camera interactive display system consisting of one camera and one projector is proposed, which enables users to interact with computer by touching on arbitrary surfaces with bare hand. The system utilizes the camera to recover 3D information of fingertip for touch detection. Firstly, predicted image generated from geometric and photometric calibration matrix is used to segment hand and its shadow. Secondly, fusion degree of the hand and its shadow is detected using linear‐scanning method. Finally, a square tracking mask is used to determine the touch action on the projection surface. Experimental results show that the proposed system is robust to different lighting conditions. The touch detection accuracy is 93.0% and the average processing time of each frame is 36 ms.     

Wideband turnstile junction coaxial waveguide orthomode transducer

A wideband turnstile junction coaxial waveguide orthomode transducer (OMT) is presented in this paper, featuring coaxial waveguide input and orthogonal rectangular waveguide outputs. It primarily comprises of a turnstile junction, bending stepped impedance transformers and power combiners. The symmetrical geometry helps achieve wide operating bandwidth and balanced output phases. The OMT covers the whole Ku band from 12 to 18 GHz, which aims at wideband dual‐polarized signal combination and separation within coaxial‐type multi‐band antenna systems. An experimental prototype is manufactured and the measured results confirm that the reflection coefficient is lower than ?15 dB within the whole band, and the port isolation is better than 35 dB. Turnstile junction coaxial waveguide OMTs can be adopted widely in circular/coaxial waveguide hybrid feeding networks for multi‐band satellite communication/remote sensing antenna systems.     

(t,n) Threshold secret image sharing scheme with adversary structure

Multimedia Tools and Applications - Secret image sharing has been researched intensively, and it has emerged as an alternative to data hiding for protecting the security and privacy of important...     

Exploring hybrid spatio-temporal convolutional networks for human action recognition

Multimedia Tools and Applications - Convolutional neural networks have achieved great success in many computer vision tasks. However, it is still challenging for action recognition in videos due to...     

Dual graph regularized NMF model for social event detection from Flickr data

In this work, we aim to discover real-world events from Flickr data by devising a three-stage event detection framework. In the first stage, a multimodal fusion (MF) model is designed to deal with the heterogeneous feature modalities possessed by the user-shared data, which is advantageous in computation complexity. In the second stage, a dual graph regularized non-negative matrix factorization (DGNMF) model is proposed to learn compact feature representations. DGNMF incorporates Laplacian regularization terms for the data graph and base graph into the objective, keeping the geometry structures underlying the data samples and dictionary bases simultaneously. In the third stage, hybrid clustering algorithms are applied seamlessly to discover event clusters. Extensive experiments conducted on the real-world dataset reveal the MF-DGNMF-based approaches outperform the baselines.     

Improved Adaptive Controller Synthesis of Piecewise‐Affine Systems

This paper considers the adaptive control problem for piecewise affine systems (PWS), a novel synthesis framework is presented based on the piecewise quadratic Lyapunov function (PQLF) instead of the common quadratic Lyapunov function to achieve the less conservatism. First, by designing the projection‐type piecewise adaptive law, the problem of the adaptive control of PWS can be reduced to the control problem of augmented piecewise systems. Then, we construct the piecewise affine control law for augmented piecewise systems in such a way that the PQLF can be employed to establish the stability and performance. In particular, the Reciprocal Projection Lemma is employed to formulate the synthesis condition as linear matrix inequalities (LMIs), which enables the proposed PQLF approach to be numerically solvable. Finally, an engineering example is shown to illustrate the synthesis results.