3D Image Labeling via 2D Projection and Point Cloud Recovery

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Solution Overview

Problem

Current 3D image labeling technologies rely on manual processes, making them costly and inefficient, and existing methods fail to maintain depth relations when converting 3D images to 2D and back, leading to confusion in labeling.

Innovation Solution

A 3D image labeling device and method that includes a point cloud cluster module, projection module, integration module, and point cloud recovery module to cluster 3D points, project them to 2D, label the objects based on 2D labeled images, and recover 3D labels, maintaining object correspondence and depth relations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual labeling is used for 3D images, then labeling accuracy can be maintained, but the cost and time consumption increase significantly

Engineering Contradiction:
Improvelabeling accuracyVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary clustering of 3D point clouds into point clusters before labeling, organizing the data in advance to facilitate more efficient processing. This preliminary structuring reduces the time required for subsequent labeling operations while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system introduces 2D projected images as an intermediary representation between the original 3D point cloud and the final labels. By projecting 3D points to 2D, applying 2D labeling techniques, and then mapping labels back to 3D space, the system leverages成熟的2D labeling algorithms to reduce time consumption while preserving 3D labeling accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If 3D images are converted to 2D for labeling, then processing efficiency improves, but depth relations and object correspondence are lost

Engineering Contradiction:
Improveprocessing efficiencyVSAvoiddepth relations
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The system systematically transforms 3D point clouds to 2D projected images for labeling, then maps the 2D labels back to 3D space. This dimensionality transformation enables the use of efficient 2D processing while recovering 3D information through careful correspondence maintenance between point clusters and their projected regions.

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

Solution Approach 2:

The system establishes bidirectional correspondence between 3D point clusters and their 2D projected regions. Labels obtained from 2D images are fed back to update the 3D point cluster annotations, ensuring that depth relations and object correspondence are preserved through the transformation cycle.

Inventive Principle:
Principle #23Feedback

3Loss of time

If automated labeling algorithms are applied directly to 3D images, then time consumption is reduced, but the technology is not yet mature and accuracy suffers

Engineering Contradiction:
Improvetime consumptionVSAvoidlabeling accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The system creates a 2D copy or projection of the 3D point cloud data, applies mature 2D automated labeling algorithms to this copy, and then transfers the labels back to the original 3D data. This copying approach allows leveraging well-established 2D algorithms while maintaining 3D labeling quality.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system replaces direct 3D automated labeling (which lacks mature algorithms) with a substituted approach using 2D projection and labeling. By substituting the labeling domain from 3D to 2D, the system can use proven 2D computer vision algorithms to achieve both speed and accuracy.

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

Data Source

PatentUS11100702B23D image labeling method based on labeling information of 2D image and 3D image labeling device
Publication Date: 2021.08.24 IND TECH RES INST
  • US11100702B2 patent drawing
  • US11100702B2 patent drawing

AI summary

A 3D image labeling device and a 3D image labeling method are provided. The 3D image labeling device includes a point cloud cluster module, a projection module, an integration module and a point cloud recovery module. The point cloud cluster module clusters multiple points of a 3D unlabeled image as one or more first point clusters according to a 3D unlabeled image and a cluster algorithm to generate a 3D clustered image. The projection module generates a first 2D image with first objects according to the 3D clustered image, wherein each first point cluster corresponds to one of the first objects. The integration module labels the first objects of the first 2D image according to one or more object frames of a 2D labeled image to generate a second 2D image. The point cloud recovery module generates a 3D labeled image according to the second 2D image.