Skip to Main content Skip to Navigation
Theses

Décompositions en ondelettes redondantes pour le codage par descriptions multiples des images fixes et des séquences vidéo

Abstract : The increasing usage of packet-based networks for multimedia transmission responds to a stringent need for data reliability under rate constraints. This thesis aims at building so-called low-redundancy "Multiple Description" representations to compensate for channel losses. We have considered schemes based on wavelet frames, implemented in a lifting form. First, two temporal descriptions have been built in a "t+2D" video codec. The initial redundancy, inherent to the frame decomposition has been lowered through an additional subsampling of the detail subbands. This allows for tuning the redundancy to the size of a classical wavelet approximation subband. However, this operation raises a perfect reconstruction issue, which has been addressed here in detail. Moreover, we have established choice criteria among the possible schemes, based on reducing the quantization noise. Then, the above methods were extended to two-dimensional signals (images). In this case we have also proposed a post-processing stage at the decoder level, in order to enhance the reconstruction quality in the event of losses. Finally, we have approached the subject from a different angle, inspired from the "Compressed Sensing" theory, by aiming at determining the best rate satisfying a maximum allowed distortion, when exploiting the sparsity of the input signal. This approach deals with the situation in which the complexity is shifted at the encoder side, while the decoders are linear.
Complete list of metadatas

Cited literature [94 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/pastel-00005906
Contributor : Ecole Télécom Paristech <>
Submitted on : Tuesday, March 23, 2010 - 8:00:00 AM
Last modification on : Friday, July 31, 2020 - 10:44:07 AM
Long-term archiving on: : Thursday, March 30, 2017 - 5:14:18 AM

Identifiers

  • HAL Id : pastel-00005906, version 1

Collections

Citation

Claudia Teodora Petrisor. Décompositions en ondelettes redondantes pour le codage par descriptions multiples des images fixes et des séquences vidéo. domain_other. Télécom ParisTech, 2009. Français. ⟨pastel-00005906⟩

Share

Metrics

Record views

435

Files downloads

593