Graph based transforms for compression of new imaging modalities

Mira Rizkallah 1, 2
2 Sirocco - Analysis representation, compression and communication of visual data
Inria Rennes – Bretagne Atlantique , IRISA-D5 - SIGNAUX ET IMAGES NUMÉRIQUES, ROBOTIQUE
Abstract : Due to the large availability of new camera types capturing extra geometrical information, as well as the emergence of new image modalities such as light fields and omni-directional images, a huge amount of high dimensional data has to be stored and delivered. The ever growing streaming and storage requirements of these new image modalities require novel image coding tools that exploit the complex structure of those data. This thesis aims at exploring novel graph based approaches for adapting traditional image transform coding techniques to the emerging data types where the sampled information are lying on irregular structures. In a first contribution, novel local graph based transforms are designed for light field compact representations. By leveraging a careful design of local transform supports and a local basis functions optimization procedure, significant improvements in terms of energy compaction can be obtained. Nevertheless, the locality of the supports did not permit to exploit long term dependencies of the signal. This led to a second contribution where different sampling strategies are investigated. Coupled with novel prediction methods, they led to very prominent results for quasi-lossless compression of light fields. The third part of the thesis focuses on the definition of rate-distortion optimized sub-graphs for the coding of omni-directional content. If we move further and give more degree of freedom to the graphs we wish to use, we can learn or define a model (set of weights on the edges) that might not be entirely reliable for transform design. The last part of the thesis is dedicated to theoretically analyze the effect of the uncertainty on the efficiency of the graph transforms.
Document type :
Theses
Complete list of metadatas

Cited literature [211 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02285386
Contributor : Abes Star <>
Submitted on : Thursday, September 12, 2019 - 4:35:36 PM
Last modification on : Saturday, September 14, 2019 - 1:21:17 AM

File

RIZKALLAH_Mira.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02285386, version 1

Citation

Mira Rizkallah. Graph based transforms for compression of new imaging modalities. Image Processing [eess.IV]. Université Rennes 1, 2019. English. ⟨NNT : 2019REN1S021⟩. ⟨tel-02285386⟩

Share

Metrics

Record views

142

Files downloads

86