Advanced Algorithmic Approaches for Improving Image Quality in 2D and 3D Holographic Displays

Holography is an advanced three-dimensional (3D) imaging and visualisation technology capable of reconstructing realistic 3D scenes. Despite decades of concentrated effort, holographic 3D displays are still struggling to meet the demands required for a consumer-ready solution. This thesis addresses technical challenges in the practical implementation and focuses specifically on potential image quality improvements based on algorithmic development. The thesis builds a holographic display system prototype and reconstructs established 3D scenes and real-world scenes using commercially available RGB-D cameras. By closely examining the reconstructed images, experimental reconstruction issues are evaluated. Given that image quality degradation is one of the significant issues in holographic displays, the gradient descent method is introduced to phase-only CGH optimisation. Contemporary image quality metrics (IQMs) considering human visual systems are employed as loss functions to improve the reconstructed image quality. Extensive objective and subjective assessment of experimentally reconstructed images reveal that the perceived quality improves considerably should the appropriate IQM loss be selected. Finally, the gradient descent method is extended to 3D hologram generation. While previous work optimises 3D CGH generation primarily on the in-focus region, this research further combines the method with an incoherent imaging module and a reformulated loss function to improve the defocus effect without sacrificing in-focus image quality. The experimentally acquired result demonstrates its effectiveness in reconstructing realistic 3D images beyond the capabilities of existing 3D hologram generation algorithms.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2022

Author dc:creator

• Yang, Fan

Advisor dc:contributor.advisor

• Wilkinson, Timothy

• Computer-generated Holography
• Hologram
• Holography

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/75cfe62f-b5ee-4f28-9928-52a7a14d477e/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

Author Identifier

0000-0003-4351-1030

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/349394