57 research outputs found

    Progressive refinement radiosity on ring-connected multicomputers

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    The progressive refinement method is investigated for parallelization on ring-connected multicomputers. A synchronous scheme, based on static task assignment, is proposed, in order to achieve better coherence during the parallel light distribution computations. An efficient global circulation scheme is proposed for the parallel light distribution computations, which reduces the total volume of concurrent communication by an asymptotical factor. The proposed parallel algorithm is implemented on a ring-embedded Intel's iPSC/2 hypercube multicomputer. Load balance quality of the proposed static assignment schemes are evaluated experimentally. The effect of coherence in the parallel light distribution computations on the shooting patch selection sequence is also investigated

    More: A Mobile Open Rich Media Environment

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    ‘Rich media ’ is a term that implies the integration of all of the ad-vances we have made in the mobile space delivering music, speech, text, graphics and video. This is true, but it is more than the sum of its parts. Rich media is the ability to deliver these modalities, to interact with these modalities, and to do it in a way that allows for the construction, delivery and use of compelling mobile services in an effective and economic manner. In this paper, we introduce a sys-tem called Mobile Open Rich-media Environment (‘MORE’) that helps realize such mobile rich media services, combining various technologies of W3C, OMA, 3GPP and IETF standards. The differ-ent components of the system include formatting, packaging, trans-porting, rendering and interacting with rich media files and streams. 1

    Parallel Processing For Progressive Refinement Radiosity

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    Progressive refinement radiosity is an increasingly popular method for realistic image synthesis of non-existing environments. The method successfully approximates the light distribution in an environment, however it requires excessive amount of computation. In this thesis, the progressive refinement method is investigated for parallelization on ring and hypercube-connected multicomputers. Two different approaches for parallelization, based on synchronous parallelism with static task assignment, are proposed, in order to achieve better coherence in parallel light distributions and obtain good performance on simple topologies. Efficient global circulation schemes are proposed in order to decrease the total volume of communication by asymptotical factors. The first scheme for parallelization is a modification of..

    A perceptual quality metric for dynamic triangle meshes

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    A measure for assessing the quality of a 3D mesh is necessary in order to determine whether an operation on the mesh, such as watermarking or compression, affects the perceived quality. The studies on this field are limited when compared to the studies for 2D. In this work, we aim a full-reference perceptual quality metric for animated meshes to predict the visibility of local distortions on the mesh surface. The proposed visual quality metric is independent of connectivity and material attributes. Thus, it is not associated to a specific application and can be used for evaluating the effect of an arbitrary mesh processing method. We use a bottom-up approach incorporating both the spatial and temporal sensitivity of the human visual system. In this approach, the mesh sequences go through a pipeline which models the contrast sensitivity and channel decomposition mechanisms of the HVS. As the output of the method, a 3D probability map representing the visibility of distortions is generated. We have validated our method by a formal user experiment and obtained a promising correlation between the user responses and the proposed metric. Finally, we provide a dataset consisting of subjective user evaluation of the quality of public animation datasets.Çipiloğlu Yıldız, Z., Capin, T. (2017). A perceptual quality metric for dynamic triangle meshes, Almanya: Springer International Publishing

    A fully object-space approach for full-reference visual quality assessment of static and animated 3D meshes

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    3D mesh models are exposed to several geometric operations such as simplification and compression. Several metrics for evaluating the perceived quality of 3D meshes have already been developed. However, most of these metrics do not handle animation and they measure the global quality. Therefore, a full-reference perceptual error metric is proposed to estimate the detectability of local artifacts on animated meshes. This is a bottom-up approach in which spatial and temporal sensitivity models of the human visual system are integrated. The proposed method directly operates in 3D mode space and generates a 3D probability map that estimates the visibility of distortions on each vertex throughout the animation sequence. We have also tested the success of our metric on public datasets and compared the results to other metrics. These results reveal a promising correlation between our metric and human perception.Institute for Systems and Technologies of Information, Control and Communication (INSTICC

    A decision theoretic approach to motion saliency in computer animations

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    We describe a model to calculate saliency of objects due to their motions. In a decision-theoretic fashion, perceptually significant objects inside a scene are detected. The work is based on psychological studies and findings on motion perception. By considering motion cues and attributes, we define six motion states. For each object in a scene, an individual saliency value is calculated considering its current motion state and the inhibition of return principle. Furthermore, a global saliency value is considered for each object by covering their relationships with each other and equivalence of their saliency value. The position of the object with highest attention value is predicted as a possible gaze point for each frame in the animation. We conducted several eye-tracking experiments to practically observe the motion-attention related principles in psychology literature. We also performed some final user studies to evaluate our model and its effectiveness
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