Entrance Pupil Distortion Parameter Refinement in HEIF

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Solution Overview

Problem

Current camera calibration methods fail to accurately account for entrance pupil distortion, leading to inaccuracies in image projection and transformation, especially in applications requiring end-to-end distortion removal.

Innovation Solution

The proposed solution involves determining camera and distortion parameters, including entrance pupil parameters, and refining these based on control points to correct for distortions, allowing for seamless integration into the High Efficiency Image File Format (HEIF) for improved image formation and manipulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current camera calibration methods are used, then the calibration process is simple, but the accuracy of image projection and transformation deteriorates due to failure to account for entrance pupil distortion

Engineering Contradiction:
Improveaccuracy of image projectionVSAvoidcomplexity of calibration method
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration method is segmented into distinct stages: initial calibration to obtain basic camera parameters, followed by a refinement stage that specifically addresses entrance pupil distortion. This segmentation allows the complex task to be broken down into manageable steps, improving accuracy without overwhelming complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method performs preliminary calibration to obtain initial camera parameters before refining the distortion parameters. This preliminary action establishes a baseline that guides the subsequent refinement process, ensuring that the complex refinement is focused and efficient rather than starting from scratch.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If entrance pupil distortion is not accounted for, then the calibration process remains simple, but the accuracy of distortion removal deteriorates in applications requiring end-to-end distortion correction

Engineering Contradiction:
Improveaccuracy of distortion removalVSAvoidcomplexity of distortion parameter modeling
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The refinement process acts as an intermediary between initial calibration and final distortion removal. It introduces controlled complexity by specifically modeling entrance pupil distortion parameters, which serve as a bridge to achieve accurate end-to-end distortion correction without requiring complete redesign of the calibration system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The method changes specific distortion parameters (entrance pupil parameters) while keeping other camera parameters fixed from the initial calibration. This selective parameter change approach improves distortion removal accuracy by focusing computational effort on the most critical distortion sources without unnecessarily complicating the entire parameter set.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If traditional calibration methods are used, then computational resources are conserved, but the mapping accuracy between 3D coordinates and 2D image projections deteriorates

Engineering Contradiction:
Improvemapping accuracy between 3D and 2DVSAvoidcomputational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The refinement process applies partial action by focusing computational resources only on optimizing entrance pupil distortion parameters rather than recalculating all camera parameters. This selective refinement achieves improved mapping accuracy while consuming fewer computational resources than a complete recalibration would require.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The method substitutes a simplified refinement model for the complete calibration mechanism. Instead of running the full calibration process again, it uses a targeted optimization approach that replaces the mechanical repetition of complete calibration with a more efficient mathematical refinement process, maintaining accuracy while improving computational efficiency.

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

Data Source

PatentUS20240020802A1Storage And Signaling Of Entrance Pupil And Distortion Parameters In Image File Format
Publication Date: 2024.01.18 NOKIA TECHNOLOGIES OY
  • US20240020802A1 patent drawing
  • US20240020802A1 patent drawing
  • US20240020802A1 patent drawing

AI summary

An apparatus may be configured to: determine at least one image; determine at least one camera parameter; determine at least one distortion parameter, wherein the at least one distortion parameter comprises at least one entrance pupil parameter; determine at least one control point of the at least one image; and refine the at least one distortion parameter based, at least partially, on the at least one control point and the at least one camera parameter.