Among a series of parameters, power quality studies are concerned with voltage unbalances, which ... more Among a series of parameters, power quality studies are concerned with voltage unbalances, which represent the voltage magnitude and phase deviation from nominal values. In order to determine the influence of the network's parameters on voltage unbalances, and to provide exact solutions to reduce or even eliminate them, the present study develops and presents two methods. First, a sensitivity analysis is used to determine the influence of each parameter, and then analytical solutions are developed in order to provide the changes needed for correction. The quantification index considered is the symmetrical components method.
The joint usage of low- and full-resolution images in multiview systems provides an attractive op... more The joint usage of low- and full-resolution images in multiview systems provides an attractive opportunity for data size reduction while maintaining good quality in 3D applications. In this paper we present a novel application of a super-resolution method for usage within a mixed resolution multiview setup. The technique borrows high-frequency content from neighboring full resolution images to enhance particular low-resolution views. Occlusions are handled through matching of low-resolution images. Both the stereo and the more general multiview cases are considered using the multiview video-plus-depth format. Results demonstrate significant gains in PSNR and in visual quality for test sequences.
A new intra-prediction mode for the H.264/AVC standard is proposed. Each pixel within a block is ... more A new intra-prediction mode for the H.264/AVC standard is proposed. Each pixel within a block is predicted by a weighted sum of its neighbours, according to an th order Markov linear model. The weights are obtained through a least-squares estimate from reconstructed data in the neighbouring blocks, so that no overhead is necessary to convey the weights to the decoder. Results show significant improvements in H.264/AVC compression for images that are rich in directional structures, and moderate improvements for the other images and sequences tested.
This work presents a new distributed multiview coding framework, based on the H.264/AVC standard ... more This work presents a new distributed multiview coding framework, based on the H.264/AVC standard operating with mixed resolution frames. It allows for a scalable complexity transfer from the encoder to the decoder, which is particularly suited for low-power video applications, such as multiview surveillance systems. Greater quality sequences are generated by exploiting the spatial and temporal correlation between views at the decoder. The results show a good potential for objective quality improvement over simulcast coding, with no extra rate cost.
Among a series of parameters, power quality studies are concerned with voltage unbalances, which ... more Among a series of parameters, power quality studies are concerned with voltage unbalances, which represent the voltage magnitude and phase deviation from nominal values. In order to determine the influence of the network's parameters on voltage unbalances, and to provide exact solutions to reduce or even eliminate them, the present study develops and presents two methods. First, a sensitivity analysis is used to determine the influence of each parameter, and then analytical solutions are developed in order to provide the changes needed for correction. The quantification index considered is the symmetrical components method.
The joint usage of low- and full-resolution images in multiview systems provides an attractive op... more The joint usage of low- and full-resolution images in multiview systems provides an attractive opportunity for data size reduction while maintaining good quality in 3D applications. In this paper we present a novel application of a super-resolution method for usage within a mixed resolution multiview setup. The technique borrows high-frequency content from neighboring full resolution images to enhance particular low-resolution views. Occlusions are handled through matching of low-resolution images. Both the stereo and the more general multiview cases are considered using the multiview video-plus-depth format. Results demonstrate significant gains in PSNR and in visual quality for test sequences.
A new intra-prediction mode for the H.264/AVC standard is proposed. Each pixel within a block is ... more A new intra-prediction mode for the H.264/AVC standard is proposed. Each pixel within a block is predicted by a weighted sum of its neighbours, according to an th order Markov linear model. The weights are obtained through a least-squares estimate from reconstructed data in the neighbouring blocks, so that no overhead is necessary to convey the weights to the decoder. Results show significant improvements in H.264/AVC compression for images that are rich in directional structures, and moderate improvements for the other images and sequences tested.
This work presents a new distributed multiview coding framework, based on the H.264/AVC standard ... more This work presents a new distributed multiview coding framework, based on the H.264/AVC standard operating with mixed resolution frames. It allows for a scalable complexity transfer from the encoder to the decoder, which is particularly suited for low-power video applications, such as multiview surveillance systems. Greater quality sequences are generated by exploiting the spatial and temporal correlation between views at the decoder. The results show a good potential for objective quality improvement over simulcast coding, with no extra rate cost.
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Papers by Diogo Garcia