3D Line Reconstruction from 2D Images Using Vanishing Points

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Solution Overview

Problem

Single view reconstruction in computer vision is challenging due to difficulties in identifying real-world intersections from apparent intersections in images, especially with occluding edges and cluttered scenes, leading to false intersections and unsatisfactory results with existing methods that rely on user interaction or synthetic data.

Innovation Solution

A method for reconstructing 3D lines in a 3D world coordinate system from 2D images using vanishing points, orthogonal structures, and an optimization procedure with linear programming to identify minimal connectivity constraints, which can handle real-world images and reduce false intersections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If line detection methods are used in real images, then lines can be detected, but false intersections and spurious lines are produced due to occluding edges and clutter

Engineering Contradiction:
Improveline detection accuracyVSAvoidintersection identification reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the image into multiple views (front, side, top) and processes lines in each view separately. By dividing the complex scene into manageable segments, the method reduces false intersections caused by clutter and occluding edges, as each view contains fewer spurious lines that could create false junctions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces vanishing points as an intermediary element to mediate between 2D line intersections and 3D spatial relationships. By using vanishing points to represent parallel lines in 3D space, the method distinguishes between apparent intersections in the image and real intersections in the scene, thereby improving intersection identification reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If geometric reconstruction methods based on line labeling are used, then 3D reconstruction can be achieved, but the problem becomes NP-hard and computationally complex

Engineering Contradiction:
Improve3D reconstruction accuracyVSAvoidcomputation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the 3D reconstruction problem into separate 2D line detection and classification tasks in front, side, and top views. This segmentation transforms the NP-hard 3D line labeling problem into simpler 2D classification problems, reducing computational complexity while maintaining reconstruction accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the problem from 3D to 2D by analyzing lines in multiple 2D views (front, side, top) rather than directly solving the 3D reconstruction problem. This dimensionality change simplifies the computational task while preserving the essential geometric relationships needed for accurate reconstruction.

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

3Manufacturing precision

If methods relying on user interaction are used, then good reconstruction results can be achieved for real images, but the ease of operation deteriorates due to manual input requirements

Engineering Contradiction:
Improvereconstruction qualityVSAvoidautomation level
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent implements self-service by automatically detecting lines, classifying them as convex/concave/occluding, and performing 3D reconstruction without user interaction. The system uses vanishing points and multi-view geometry to autonomously resolve ambiguities that previously required manual input, thereby maintaining high reconstruction quality while improving ease of operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes key parameters such as using vanishing points to represent parallel lines and employing specific classification criteria for line segments. These parameter changes enable the system to automatically distinguish between real and false intersections, achieving good reconstruction results without user interaction.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If synthetic line drawings are used for training and testing, then constraint satisfaction methods can be developed, but adaptability to real-world images deteriorates

Engineering Contradiction:
Improvemethod development feasibilityVSAvoidreal-world image applicability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent uses synthetic line drawings as simplified copies of real scenes for developing and testing the constraint satisfaction method. However, it then adapts the method to real-world images by using vanishing points and multi-view geometry, which are universally applicable regardless of whether the input is synthetic or real, thereby improving adaptability while maintaining development feasibility.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS9183635B2Method for reconstructing 3D lines from 2D lines in an image
Publication Date: 2015.11.10 MITSUBISHI ELECTRIC RESEARCH LABORATORIES INC
  • US9183635B2 patent drawing
  • US9183635B2 patent drawing
  • US9183635B2 patent drawing

AI summary

A method for reconstructing—three-dimensional (3D) lines in a 3D world coordinate system from two-dimensional (2D) lines in a single image of scene detects and clusters the 2D lines using vanishing points. A constraint graph of vertices and edges is generated, wherein the vertices represent the 2D lines, and the edges represents constraints on the 2D lines, then identifying the 3D lines that satisfy the constraints and reconstructing the 3D lines using the identified constraints.