Novel View Synthesis via Optical Flow and Epipolar Constraints

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Solution Overview

Problem

Conventional novel view synthesis techniques require numerous existing images and significant field-of-view overlap, making them time-consuming and inefficient, especially when generating images for novel viewpoints.

Innovation Solution

The method employs optical flow and epipolar constraints to synthesize a target image from only two source images, using pixel attribute correspondences and geometric relationships to identify source pixels and transfer attributes directly, eliminating the need for volumetric scene representation and reducing field-of-view overlap requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional techniques use tens or hundreds of existing images for novel view synthesis, then the synthesized image quality is improved, but the time consumption and computational complexity increase significantly

Engineering Contradiction:
Improvesynthesized image qualityVSAvoidtraining time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent extracts and utilizes only the essential geometric constraints (epipolar lines) and pixel correspondences (optical flow) from the scene, eliminating the need to process tens or hundreds of images. By focusing on the critical minimal set of constraints required for view synthesis, the method achieves accurate results with just two source images, dramatically reducing training time and computational overhead while maintaining synthesized image quality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent copies pixel attributes (color, texture, feature descriptors) directly from source images to the target image using optical flow-based correspondence matching. This copying approach bypasses the need for complex volumetric representation and extensive neural network training, enabling efficient novel view synthesis with minimal source images while preserving image quality through direct attribute transfer

Inventive Principle:
Principle #26Copying

2Reliability

If conventional techniques require significant field-of-view overlap between source images, then the synthesis reliability is improved, but the adaptability to novel viewpoints is reduced

Engineering Contradiction:
Improvesynthesis reliabilityVSAvoidnovel viewpoint coverage
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent shifts from requiring spatial field-of-view overlap to utilizing temporal or arbitrary viewpoint relationships. By employing optical flow to capture pixel correspondences across different time points or viewpoints and using epipolar geometry to establish constraints, the method can synthesize images for viewpoints between or outside the source images without requiring significant spatial overlap, thereby enhancing adaptability while maintaining reliability through geometric constraints

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

Solution Approach 2:

The patent changes the critical parameters from field-of-view overlap to epipolar geometric constraints and optical flow correspondences. By relying on these parameter changes, the method can work with minimal or no field-of-view overlap between source images, enabling synthesis for a broader range of novel viewpoints while maintaining synthesis reliability through the mathematical constraints of epipolar geometry and the motion information from optical flow

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If conventional techniques construct volumetric representation of the 3D scene, then the completeness of scene understanding is improved, but the device complexity and computational requirements increase

Engineering Contradiction:
Improvescene understanding completenessVSAvoidsystem complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent extracts only the essential 2D image space information (pixel attributes, optical flow, epipolar constraints) needed for novel view synthesis, eliminating the complex step of constructing full volumetric 3D scene representations. This extraction approach maintains sufficient scene understanding for the synthesis task while dramatically reducing system complexity and computational requirements by working directly in 2D image space

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical process of constructing and manipulating volumetric 3D representations with a more efficient optical-geometric approach using epipolar constraints and optical flow in 2D image space. This substitution eliminates the computational overhead of volumetric rendering while achieving the same novel view synthesis objective through direct pixel attribute transfer constrained by geometric relationships

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11783532B1View synthesis using attribute correspondences and geometric relationship constraints
Publication Date: 2023.10.10 NVIDIA CORP
  • US11783532B1 patent drawing
  • US11783532B1 patent drawing
  • US11783532B1 patent drawing

AI summary

A target image corresponding to a novel view may be synthesized from two source images, corresponding source camera poses, and pixel attribute correspondences between the two source images. A particular object in the target image need only be visible in one of the two source images for successful synthesis. Each pixel in the target image is defined according to an identified pixel in one of the two source images. The identified source pixel provides attributes such as color, texture, and feature descriptors for the target pixel. The source and target camera poses are used to define geometric relationships for identifying the source pixels. In an embodiment, the pixel attribute correspondences are optical flow that defines movement of attributes from a first image of the two source images to a second image of the two source images.