Photogrammetric Relief Modeling With Multi-Stereo Disparity Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for generating relief models through photogrammetry suffer from information loss due to the conversion of unitary correlation results into unitary relief representation models and subsequent merging, which fails to capture overhanging terrain structures and degrades information through re-sampling.

Innovation Solution

A method involving the calculation of geometric disparities based on a predetermined relief representation model, using a cost function to optimize the gradient descent, and iteratively updating the model to minimize information loss by considering all pairs of stereo images, rather than individual pairs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If unitary correlation results are converted into unitary relief representation models and merged, then the relief model can be generated from multiple stereo image pairs, but information loss occurs and overhanging terrain structures cannot be represented

Engineering Contradiction:
Improveinformation lossVSAvoidprocessing complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent merges the processing of multiple stereo image pairs by directly integrating their correlation results into a single relief representation model through iterative optimization, rather than converting each pair separately and then merging the models. This combines the information from all stereo pairs at the correlation level, preserving overhanging terrain structures and minimizing information loss while maintaining computational feasibility through the iterative gradient descent approach.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If relief representation model is sampled over a certain grid, then the model can be represented in digital format, but re-sampling degrades the information

Engineering Contradiction:
Improveinformation precisionVSAvoidmodel precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent performs the grid sampling and discretization as a preliminary action only at the final stage, after all correlation results from multiple stereo image pairs have been integrated through iterative optimization. The continuous relief model is then sampled onto a digital grid, which preserves information precision because the sampling occurs after the complete information integration, rather than requiring intermediate re-sampling operations that would degrade the data.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If iterative optimization is performed to minimize information loss, then the relief model accuracy is improved, but the processing time increases

Engineering Contradiction:
Improvemodel accuracyVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements iterative gradient descent optimization to minimize the cost function representing information loss, but applies partial action by using practical stopping criteria such as maximum iteration limits or convergence thresholds. This allows the optimization to improve model accuracy by integrating correlation results from multiple stereo pairs, while preventing excessive processing time by terminating iterations when sufficient accuracy is achieved or a predefined maximum is reached.

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces information loss by directly generating a relief representation model from all stereo images, preserving detailed terrain features and improving the accuracy of the final model.

Implementation Method 1

The generation of a model representing relief, such as a digital surface model (DSM) or a digital elevation model (DEM), by photogrammetry consists in reconstructing a scene in three dimensions (3D) using the parallax obtained between stereo images

Methodology Applied
Scientific EffectParallax: Parallax

Implementation Method 2

calculations of the correlation between the stereo images are carried out and used to reconstruct the scene

Methodology Applied
Scientific EffectCorrelation calculation:

Data Source

PatentUS12541922B2Method for generating a model for representing relief by photogrammetry
Publication Date: 2026.02.03 AIRBUS DEFENCE & SPACE SAS
  • US12541922B2 patent drawing
  • US12541922B2 patent drawing
  • US12541922B2 patent drawing

AI summary

A method for generating a relief representation model using a plurality of N pairs of stereo images, each of the N pairs of stereo images being associated with a map of photogrammetric disparities which is obtained by correlation calculation based on the pair of stereo images in question, comprises: a calculation of maps of geometric disparities based on a predetermined relief representation model, by projection of the predetermined relief representation model into an epipolar geometry of the pairs of stereo images; a calculation of a cost function, representative of a difference between the geometric and photogrammetric disparities, associated with the predetermined relief representation model; and an updating of the predetermined relief representation model by optimization of the gradient descent type of the cost function, and iteration until a predefined endpoint criterion is reached. Also a computer program and a system.