Realizing a Low-Power Head-Mounted Phase-Only Holographic Display by Light-Weight Compression

Area of Science:

• Optoelectronics and Display Technologies
• Computer Vision and Graphics
• Data Compression and Transmission

Background:

• Head-mounted holographic displays (HMHD) are emerging as a key technology for holographic video.
• Liquid Crystal on Silicon (LCoS) spatial light modulators (SLM) are suitable for phase-only holograms (POH).
• Current mobile processors lack the computational power for real-time POH generation required by HMHDs.

Purpose of the Study:

• To design a feasible HMHD-based augmented reality system by addressing computational and power constraints.
• To investigate compression strategies for transmitting display-ready POH from a server to an HMHD.
• To focus on low-power decoder implementations for HMHDs.

Main Methods:

• Analysis of performance/watt requirements for HMHD systems.
• Exploration of compression techniques for display-ready POH, considering rate-distortion trade-offs.
• Evaluation of 2D phase unwrapping and flat quantization effects on compression.
• Proposal of a versatile Phase-only Hologram (POH) codec with progressive quantization and per-pixel rate-distortion control.

Main Results:

• Identified a significant compute power gap for real-time POH generation on HMHDs.
• Demonstrated that adaptive compression of display-ready POH is feasible for current wireless technologies.
• Achieved acceptable POH quality at target bitrates of 60-200 Mbit/s.
• Confirmed the feasibility of low-power, quality-ensured, interactive HMHD augmented reality systems.

Conclusions:

• A feasible design for HMHD-based augmented reality systems is presented, focusing on efficient POH compression.
• The proposed adaptive POH codec with light-weight decoding enables low-power, high-quality HMHD experiences.
• Commercial components and current wireless technologies can support interactive, multi-user HMHD augmented reality systems.