Sparse Light Field Representation via Depth Estimation

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Solution Overview

Problem

Light fields with high spatial-angular resolution require significant storage space and are difficult to process efficiently, as they often involve large datasets that need to be kept in memory.

Innovation Solution

A sparse representation method that estimates depth from high spatio-angular resolution light fields by storing depth estimates and error between reconstructions and images, allowing for compact storage and efficient reconstruction of the light field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high spatial-angular resolution light fields are captured using multiple high resolution images, then the light field quality and detail are improved, but the storage space requirements increase enormously

Engineering Contradiction:
Improvespatial-angular resolutionVSAvoidstorage space
Core Design Contradiction:
Measurement precisionVSVolume of stationary object

Solution Approach 1:

The patent extracts and stores only the essential depth information from the light field data, separating the critical structural information (depth estimates) from the redundant full-resolution image data. This extraction approach maintains the ability to reconstruct light fields while dramatically reducing storage requirements from hundreds of high-resolution images to compact depth maps and error representations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the light field representation from storing complete high-resolution images to storing depth parameter estimates and error terms. This parameter transformation changes the data structure from pixel-intensive image arrays to compact depth maps, enabling efficient storage while preserving the essential geometric information needed for light field reconstruction.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If full depth-of-field images for different viewpoints are merged and stacked in a 4D volume, then complete light field representation is achieved, but processing becomes difficult and memory-intensive

Engineering Contradiction:
Improvelight field completenessVSAvoidprocessing complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent creates a simplified copy of the light field information by storing depth estimates rather than complete image stacks. This copying approach captures the essential geometric structure of the light field in a compact form, enabling reconstruction without requiring the full 4D volume of high-resolution images to be loaded into memory for processing.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent adds a depth dimension to the representation by storing depth maps alongside error terms, transforming the problem from managing large 4D image volumes to working with compact depth-parameter representations. This dimensional transformation enables efficient processing by organizing information according to depth layers rather than spatial-viewpoint dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2806396B1Sparse light field representation
Publication Date: 2018.08.29 DISNEY ENTERPRISES INC
  • EP2806396B1 patent drawingFigure 1A~1C
  • EP2806396B1 patent drawingFigure 2A~2C
  • EP2806396B1 patent drawingFigure 3A~3B

AI summary

The disclosure provides an approach for generating a sparse representation of a light field. In one configuration, a sparse representation application receives a light field constructed from multiple images, and samples and stores a set of line segments originating at various locations in epipolar-plane images (EPI), until the EPIs are entirely represented and redundancy is eliminated to the extent possible. In addition, the sparse representation application determines and stores difference EPIs that account for variations in the light field. Taken together, the line segments and the difference EPIs compactly store all relevant information that is necessary to reconstruct the full 3D light field and extract an arbitrary input image with a corresponding depth map, or a full 3D point cloud, among other things. This concept also generalizes to higher dimensions. In a 4D light field, for example, the principles of eliminating redundancy and storing a difference volume remain valid.