[Paper Review] RLFC: Random Access Light Field Compression using Key Views.

Srihari Pratapa, Dinesh Manocha|arXiv (Cornell University)|May 15, 2018

Advanced Vision and Imaging8 references4 citations

TL;DR

RLFC is a hierarchical light field compression scheme that uses a tree-structured representation to exploit redundancies across views, enabling random access and fast hardware decoding via bounded integer sequence encoding. It achieves 20:1 to 200:1 compression ratios at 40–50 dB PSNR with sub-microsecond per-channel decompression and 200 fps view rendering at 512×512 resolution.

ABSTRACT

We present a new hierarchical compression scheme for encoding light field images (LFI) that is suitable for interactive rendering. Our method (RLFC) exploits redundancies in the light field images by constructing a tree structure. The top level (root) of the tree captures the common high-level details across the LFI, and other levels (children) of the tree capture specific low-level details of the LFI. Our decompressing algorithm corresponds to tree traversal operations and gathers the values stored at different levels of the tree. Furthermore, we use bounded integer sequence encoding which provides random access and fast hardware decoding for compressing the blocks of children of the tree. We have evaluated our method for 4D two-plane parameterized light fields. The compression rates vary from 0.08 - 2.5 bits per pixel (bpp), resulting in compression ratios of around 200:1 to 20:1 for a PSNR quality of 40 to 50 dB. The decompression times for decoding the blocks of LFI are 1 - 3 microseconds per channel on an NVIDIA GTX-960 and we can render new views with a resolution of 512X512 at 200 fps. Our overall scheme is simple to implement and involves only bit manipulations and integer arithmetic operations.

Motivation & Objective

• To address the challenge of efficiently compressing light field images for interactive rendering with low latency.
• To reduce redundancy across multiple views in 4D light fields while preserving high visual quality.
• To enable random access and fast hardware decoding for real-time applications.
• To develop a simple, bit-parallel compression scheme using only integer arithmetic and bit operations.

Proposed method

• The method constructs a hierarchical tree structure where the root captures common high-level features across the light field.
• Child nodes store view-specific low-level details, enabling progressive refinement of reconstructed views.
• A bounded integer sequence encoding technique is applied to compress child block data, supporting random access and fast decoding.
• Tree traversal during decompression aggregates values from different levels to reconstruct the full light field.
• The scheme uses only bit manipulations and integer arithmetic, enabling efficient hardware implementation.
• The approach is evaluated on 4D two-plane parameterized light fields using standard compression metrics.

Experimental results

Research questions

• RQ1 Can a hierarchical tree-based compression model effectively exploit inter-view redundancies in light field images?
• RQ2 How efficiently can random access and fast decoding be achieved in light field compression using integer arithmetic?
• RQ3 What compression ratios and visual quality are attainable with minimal computational overhead?
• RQ4 Can the method support real-time rendering at high frame rates for interactive applications?
• RQ5 To what extent does the scheme maintain high PSNR while achieving low bitrates?

Key findings

• The method achieves compression ratios of 20:1 to 200:1 at PSNR values between 40 dB and 50 dB.
• Compression rates range from 0.08 to 2.5 bits per pixel, indicating high efficiency.
• Decompression time is 1–3 microseconds per channel on an NVIDIA GTX-960 GPU.
• The system supports real-time rendering of 512×512 resolution views at 200 frames per second.
• The scheme is highly efficient in practice, relying only on bit manipulations and integer arithmetic.
• The approach enables random access and is well-suited for hardware acceleration due to its simplicity.