3D Object Attitude Estimation Using Illumination-Invariant Features

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Solution Overview

Problem

Existing methods for estimating the attitude of objects in a three-dimensional space face challenges such as reduced accuracy due to changes in illumination conditions, the need for capturing points on the object's surface, and the difficulty of using regression models with defective input data, especially when multiple objects cannot be discriminated from each other.

Innovation Solution

The proposed solution involves a multi-step process using a computer to calculate representative points from images obtained by multiple imaging devices, estimate the positions of objects in 3D space, extract feature amounts from image regions, and use a preliminarily learned regression model to estimate the attitudes of objects based on their positions and feature amounts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If images themselves are used for attitude estimation, then the method is simple to implement, but the estimation accuracy is reduced by changes in illumination condition

Engineering Contradiction:
Improveease of implementationVSAvoidattitude estimation accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent extracts specific feature quantities from images that are invariant to illumination changes, such as contour shapes and geometric properties, rather than using raw image data. This extraction process isolates the essential attitude-related information while removing illumination-dependent variations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms image data into different parameter representations (feature quantities) that are less sensitive to illumination changes. By changing from raw pixel values to extracted geometric and structural features, the system achieves illumination invariance while maintaining attitude estimation capability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If points on the surface of a three-dimensional object are captured, then the attitude can be calculated using point positions, but the attitude cannot be estimated when these points cannot be observed

Engineering Contradiction:
Improveattitude calculation accuracyVSAvoidattitude estimation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent creates a universal attitude estimation system that works with multiple types of input data (images, point clouds, feature quantities) and can handle various observation conditions. The system can estimate attitude whether surface points are directly observable or only indirect features are available, making the method universally applicable.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces feature quantities as an intermediary between raw observations and attitude estimation. These features serve as mediators that can be derived from various sources (images, partial point clouds) and reliably indicate attitude even when direct surface point observation is impossible.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a regression model is used for attitude estimation, then the method can be learned from pair data, but it is difficult to achieve when part of input data includes a defect

Engineering Contradiction:
Improvelearning capabilityVSAvoidattitude estimation reliability with defective data
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent performs preliminary processing of input data to identify and handle defective regions before attitude estimation. By pre-processing images and point clouds to detect defects and compensate for missing information, the system ensures reliable input data for the regression model even when original observations are imperfect.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent prepares multiple complementary data sources and feature extraction methods in advance to cushion against potential data defects. If one input source is defective, alternative sources or feature representations can compensate, ensuring the regression model always receives sufficient valid information.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Reliability

If multiple regression models are prepared for different defect situations, then the attitude can be estimated even with defective input data, but the system complexity increases

Engineering Contradiction:
Improveattitude estimation reliability with defective dataVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent develops a single universal regression model that can handle various defect situations through flexible feature engineering and data preprocessing. Rather than creating multiple specialized models, one robust model processes all cases by adapting to the quality and type of available input data.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the parameter representation of input data dynamically based on defect detection, transforming defective inputs into suitable feature formats that the single regression model can process effectively. This parameter adaptation allows one model to replace multiple specialized models.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12211234B2Estimation method, estimation apparatus and program
Publication Date: 2025.01.28 NIPPON TELEGRAPH & TELEPHONE CORP
  • US12211234B2 patent drawing
  • US12211234B2 patent drawing
  • US12211234B2 patent drawing

AI summary

An estimation step according to an embodiment causes a computer to execute: a calculation step of using a plurality of images obtained by a plurality of imaging devices imaging a three-dimensional space in which a plurality of objects reside, to calculate representative points of pixel regions representing the objects among pixel regions of the images; a position estimation step of estimating positions of the objects in the three-dimensional space, based on the representative points calculated by the calculation step; an extraction step of extracting predetermined feature amounts from image regions representing the objects; and an attitude estimation step of estimating attitudes of the objects in the three-dimensional space, through a preliminarily learned regression model, using the positions estimated by the position estimation step, and the feature amounts extracted by the extraction step.