Skip to Main content Skip to Navigation
Theses

Fast hologram synthesis methods for realistic 3D visualization

Abstract : Holography is often considered as the most promising 3D visualization technology, since it can produce the most realistic and natural depth illusion to the naked eye. However, in order to have application in the field of videoconferencing or telepresence systems, hologram synthesis methods should be able to produce realistic 3D scenes with strong depth illusion in real-time. This thesis falls within this context and is organized into two parts. In the first part of this work, we investigated two novel algorithms in order to get closer to real-time computation. First, we designed a fast hologram calculation method by combining two approaches which complement one another: the point-source and wave-field approaches. Whereas previously proposed methods reduced the computational complexity of these approaches independently, our method takes advantages from both of them. By this way, the hologram calculation time has been reduced by more than 65% compare to the conventional point-source and wave-field methods. Second, we further accelerated this hybrid method by removing temporal redundancies between consecutive frames of a 3D video. For each video frame, the algorithm detects changes in the scene and updates the hologram of only affected scene points. Since only small regions of the hologram are updated at each video frame, this method allows the computational burden to be dramatically reduced, enabling the computation of colorful video holograms at 60 frames per second. In the second part of this work, we proposed two algorithms in order to enhance the visual quality of displayed scenes. First, we improved the hybrid method to take into account occlusions between objects in the scene. To this end, we designed an efficient algorithm for light shielding between points and light waves. Experimental results revealed that this method provides occlusion effect without significantly increasing the hologram calculation time of the original hybrid method. Finally, we proposed a hologram computation method from Multiview-plus-depth (MVD) data with rendering of specular reflections. In this method, the 3D scene geometry is first reconstructed from the MVD data as a layered point-cloud, enabling the use of only a few perspective projections of the scene. Furthermore, in order to take into account specular reflections, each scene point is considered to emit light differently in all the directions. Finally, light scattered by the scene is numerically propagated towards the hologram plane in order to get the final hologram. Experimental results show that the proposed method is able to provide all the human depth cues and accurate shading of the scene with reduced computational complexity.
Complete list of metadata

Cited literature [228 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01392677
Contributor : ABES STAR :  Contact
Submitted on : Friday, November 4, 2016 - 3:48:06 PM
Last modification on : Thursday, August 26, 2021 - 3:09:43 AM
Long-term archiving on: : Sunday, February 5, 2017 - 2:11:54 PM

File

These_GILLES_Antonin2.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01392677, version 1

Collections

Citation

Antonin Gilles. Fast hologram synthesis methods for realistic 3D visualization. Signal and Image processing. INSA de Rennes, 2016. English. ⟨NNT : 2016ISAR0005⟩. ⟨tel-01392677⟩

Share

Metrics

Record views

400

Files downloads

566