Using Content Analysis for Video Compression

This paper suggests the idea to model video information as a concatenation of different recurring sources. For each source a different tailored compressed representation can be optimally designed so as to best match the intrinsic characteristics of the viewed scene. Since in a video, a shot or scene with similar visual content recurs more than once, even at distant intervals in time, this enables to build a more compact representation of information. In a specific implementation of this idea, we suggest a content-based approach to structure video sequences into hierarchical summaries, and have each such summary represented by a tailored set of dictionaries of codewords. Vector quantization techniques, formerly employed for compression purposes only, have been here used first to represent the visual content of video shots and then to exploit visual-content redundancy inside the video. The depth in the hierarchy determines the precision in the representation both from a structural point of view and from a quality level in reproducing the video sequence. The effectiveness of the proposed method is demonstrated by preliminary tests performed on a limited collection of video-data excerpted from a feature movie. Some additional functionalities such as video skimming may remarkably benefit from this type of representation

Hierarchical Video Summaries by Dendrogram Cluster Analysis

In the current video analysis scenario, effective summarization of video sequences through shot clustering facilitates the access to the content and helps in understanding the associated semantics. This paper introduces a generic scheme to produce hierarchical summaries of the video document starting from a dendrogram representation of clusters of shots. The evaluation of the cluster distortions, and the exploitation of the dependency relationships between clusters on the dendrograms, allow to obtain only a few semantically significant summaries of the whole video. Finally the user can navigate through summaries and decide which one best suites his/her needs for eventual post-processing. The effectiveness of the proposed method is demonstrated by testing it on a collection of video-data from different kinds of programmes, using and comparing different visual features on color information. Results are evaluated in terms of metrics that measure the content representational value of the summarization technique

Extraction of Significant Video Summaries by Dendrogram Analysis

In the current video analysis scenario, effective clustering of shots facilitates the access to the content and helps in understanding the associated semantics. This paper introduces a cluster analysis on shots which employs dendrogram representation to produce hierarchical summaries of the video document. Vector quantization codebooks are used to represent the visual content and to group the shots with similar chromatic consistency. The evaluation of the cluster codebook distortions, and the exploitation of the dependency relationships on the dendrograms, allow to obtain only a few significant summaries of the whole video. Finally the user can navigate through summaries and decide which one best suites his/her needs for eventual post-processing. The effectiveness of the proposed method is demonstrated by testing it on a collection of video-data from different kinds of programmes. Results are evaluated in terms of metrics that measure the content representational value of the summarization technique

Video Shot Clustering and Summarization through dendrograms

In the context of analysis of video documents, effective clustering of shots facilitates the access to the content and helps in understanding the associated semantics. This paper introduces a cluster analysis on video shots which employs dendrogram representation to produce hierarchical summaries of the video document. Vector quantization codebooks are used to represent the visual content and to group the shots with similar chromatic consistency. The evaluation of the cluster codebook distortions, and the exploitation of the dependency relationships on the dendrogram, allow to obtain only a few significant summaries of the whole video. Finally the user can navigate through summaries and decide which one best suites his/her needs for eventual post processing. The effectiveness of the proposed method is demonstrated, on a collection of different video programmes, in term of metrics that measure the content representational value of the summarization technique

Multi-mode mediated exchange coupling in cavity QED

Microwave cavities with high quality factors enable coherent coupling of distant quantum systems. Virtual photons lead to a transverse exchange interaction between qubits, when they are non-resonant with the cavity but resonant with each other. We experimentally probe the inverse scaling of the inter-qubit coupling with the detuning from a cavity mode and its proportionality to the qubit-cavity interaction strength. We demonstrate that the enhanced coupling at higher frequencies is mediated by multiple higher-harmonic cavity modes. Moreover, in the case of resonant qubits, the symmetry properties of the system lead to an allowed two-photon transition to the doubly excited qubit state and the formation of a dark state.Comment: 9 pages, 6 figure

Sistemas silvipastoris: alternativa para Amazônia.

Made available in DSpace on 2014-08-08T06:50:13Z (GMT). No. of bitstreams: 1 Revistav.6n3Sistemassilvipastoris.pdf: 27313 bytes, checksum: 7b566f16d62e0e439847549a7e22d996 (MD5) Previous issue date: 2005-01-1

Sistemas silvipastoris: alternativa para Amazônia.

O sistema silvipastoril, exploração na qual se juntam, numa só área, árvores, pastagens e animais, vem despertando crescente interesse da classe científica graças aos benefícios econômicos, sociais e, principalmente, ecológicos. Este artigo tem como objetivo divulgar este sistema de produção, como estratégia sustentável para a região amazônica