Realistic Defocus Blur for Multiplane Computer-Generated Holography (Presentation @ieeevr2023 )

Introduction

In this section, the speaker introduces himself and presents the paper on realistic defocus blur for multiplane computer-generated holography.

Speaker Introduction

• The speaker is Koray Kavaklı, a PhD student from Koç University and University College London.

• He presents a paper on realistic defocus blur for multiplane computer-generated holography.

• The paper is a product of an ongoing collaboration between Koç University, the University of Tokyo, and University College London.

Importance of Computer Generated Holography

In this section, the speaker discusses the importance of computer-generated holography as a next-generation display technology.

Computer Generated Holography

• Holographic displays have been getting lots of attention in recent years.

• There is a growing consensus that computer-generated holography can stand out as the next-generation display technology.

• The visual quality of images generated by CGH has been tremendously increased thanks to recent works in literature.

• Interactive refresh rates in holographic displays are no longer a dream.

Challenges with Defocused Parts in CGH

In this section, the speaker discusses challenges with defocused parts in CGH and how it affects image quality.

Challenges with Defocused Parts

• Prior works increase image quality tremendously; however, there still remains a barrier to achieving realistic visuals with CGH.

• As holographic displays rely on coherent light sources, the defocused part of the scene suffers from high-frequency ringing artifacts known as edge fringe effects.

• The defocused part of a scene looks unfamiliar for a human observer due to some coherent transfer function characteristics of the lasers.

• Both conventional and state-of-the-art algorithms suffer from edge fringe artifacts and provide inaccurate defocus blur.

Proposed Solution

In this section, the speaker presents their proposed solution to overcome challenges with defocused parts in CGH.

Proposed Solution

• The speaker proposes a new targeting scheme to set target images for multiplane reconstructions.

• They derived a new loss function that pays special attention to both focus and defocus parts of CGH calculations.

• Using their newly derived loss function as well as targeting scheme, they establish a hologram generation pipeline for multiplane images.

• Their pipeline generates an improved version for the phase holograms for a given three-dimensional scene.

Conclusion

In this section, the speaker concludes their presentation on realistic defocus blur for multiplane computer-generated holography.

Conclusion

• The speaker's proposed method mitigates issues in reconstructed images caused by edge fringe artifacts and inaccurate defocus blur.

• The proposed method can be used within any optimizer in literature such as Gerchberg Saxton and gradient descent optimizers.

• They validated their results from their benchtop holographic display prototype.

Building a Real Holographic Display Prototype

In this section, the speaker discusses building a real holographic display prototype with SLM, laser source, and off-the-shelf optical components. They also show real-world captures acquired from their holographic display.

Real Holographic Display Prototype

• Built a real holographic display prototype with SLM, Laser Source and off-the-shelf Optical components.

• Showed real-world captures acquired from their holographic display as the focus gradually changes between different planes.

Comparison Against State-of-the-Art Methods

• Compared their method against state-of-the-art methods while targeting sparse content dominated by black pixels.

• Addressed their results against other methods in terms of common image metrics.

• Their method provides the best scores across all the image metrics with respect to other methods.

Augmented Reality Prototype

• Extended benchtop holographic display prototype as an augmented reality prototype by adding an eyepiece lens and a beam splitter.

• Showed photographs captured using their augmented reality holographic display prototype. The focus part of objects is annotated with red patch lines with respect to the real-life in-focus objects that are annotated with red arrows.

Multiplane Hologram Generation Pipeline

• Utilized new multiplane hologram generation pipeline in beaming displays. It is an emerging alternative to conventional augmented reality glasses designs which removes active components such as batteries and electronics from AR glasses and moves them to a projector.

Conclusion and Additional Resources

In this section, the speaker concludes their talk on building a real holographic display prototype and provides additional resources for those interested in their work.

• This work is also a part of the conference, please check out this talk as well if you are interested.

• Provided links to their manuscript and supplementary material for more results and their codebase for replication.

• Mentioned a course they presented in SIGGRAPH 2022 that can jump-start research in this area.