The failed liberalisation of Algeria and the international context: a legacy of stable authoritarianism

The paper attempts to challenge the somewhat marginal role of international factors in the study of transitions to democracy. Theoretical and practical difficulties in proving causal mechanisms between international variables and domestic outcomes can be overcome by defining the international dimension in terms of Western dominance of world politics and by identifying Western actions towards democratising countries. The paper focuses on the case of Algeria, where international factors are key in explaining the initial process of democratisation and its following demise. In particular, the paper argues that direct Western policies, the pressures of the international system and external shocks influence the internal distribution of power and resources, which underpins the different strategies of all domestic actors. The paper concludes that analysis based purely on domestic factors cannot explain the process of democratisation and that international variables must be taken into more serious account and much more detailed

Hand Orientation Regression Using Random Forest for Augmented Reality

We present a regression method for the estimation of hand orientation using an uncalibrated camera. For training the system, we use a depth camera to capture a large dataset of hand color images and orientation angles. Each color image is segmented producing a silhouette image from which contour distance features are extracted. The orientation angles are captured by robustly fitting a plane to the depth image of the hand, providing a surface normal encoding the hand orientation in 3D space. We then train multiple Random Forest regressors to learn the non-linear mapping from the space of silhouette images to orientation angles. For online testing of the system, we only require a standard 2D image to infer the 3D hand orientation. Experimental results show the approach is computationally efficient, does not require any camera calibration, and is robust to inter-person shape variation

Motion Capture of Hands in Action Using Discriminative Salient Points

Abstract. Capturing the motion of two hands interacting with an object is a very challenging task due to the large number of degrees of freedom, self-occlusions, and similarity between the fingers, even in the case of multiple cameras observing the scene. In this paper we propose to use discriminatively learned salient points on the fingers and to estimate the finger-salient point associations simultaneously with the estimation of the hand pose. We introduce a differentiable objective function that also takes edges, optical flow and collisions into account. Our qualitative and quantitative evaluations show that the proposed approach achieves very accurate results for several challenging sequences containing hands and objects in action.

Physikalische zeitschrift, T. XIII, 1912

Pas de Résumé disponibl

Real-time Video-based Character Animation

The ability to animate a 3D virtual character in real-time has great potential in terms of connecting and interacting with an audience or individual user, for example allowing a virtual character to answer questions from audience members or make spontaneous comments about a show, or by allowing a gamer to represent themselves more effectively in the game world. Existing professional animation production methods such as digital puppetry, based on complex manual controllers, and optical performance capture, based on reflective markers require specialist equipment, on-set expertise, time consuming setup and are therefore not appropriate for a mass market consumer context, and their relative expense limits their use in real-time professional media production. Recently systems have been demonstrated that reduce these requirements somewhat [Weise et al. 2011], but still require emerging specialist consumer grade 3D capture devices. We have developed a new method of real-time character animation that requires no expertise and uses widely available consumergrade camera equipment as input and that can be deployed on standard hardware such as laptops and mobile devices

Physikalische Zeitschrift; t. XIV; 1913

Pas de Résumé disponibl

Physikalische Zeitschrift; t. XIII; 1912

Pas de Résumé disponibl