Camera Parameter Estimation Using Principal-Point Likelihood Heatmaps

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Solution Overview

Problem

Existing camera calibration methods fail to accurately estimate camera parameters based on the distribution of image principal points at each pixel, leading to inaccuracies in camera calibration.

Innovation Solution

A camera parameter calculation device that generates a heatmap representing the likelihood of image principal points at each pixel using a learning model trained by machine learning, allowing the estimated image principal points to approach their true values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional geometry-based methods or deep learning methods are used for camera calibration, then the calibration process can be performed, but the camera parameter estimation accuracy is insufficient

Engineering Contradiction:
Improvecamera parameter estimation accuracyVSAvoidlikelihood distribution utilization
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the camera calibration problem into two distinct stages: (1) generating a heatmap representing the likelihood distribution of image principal points at each pixel using a learning model, and (2) calculating camera parameters based on this heatmap. This segmentation allows the system to explicitly model and utilize the likelihood distribution, thereby improving estimation accuracy while maintaining calibration reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a heatmap as an intermediary representation between the input image and the final camera parameter estimation. This heatmap serves as a probability distribution map that highlights likely locations of image principal points, enabling the system to incorporate uncertainty information and likelihood distributions into the calibration process, thus resolving the contradiction between precision and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a learning model is trained to estimate image principal points, then the estimation can be performed, but the accuracy is limited without utilizing likelihood distribution

Engineering Contradiction:
Improveimage principal point estimation accuracyVSAvoidlikelihood distribution information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent performs preliminary action by generating a heatmap that represents the likelihood distribution of image principal points before final camera parameter calculation. This preliminary heatmap generation captures and preserves the likelihood distribution information that would otherwise be lost, allowing subsequent parameter estimation to benefit from this probabilistic information and achieve higher accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the generated heatmap to guide the camera parameter calculation process. The heatmap provides feedback about the likelihood distribution of principal points, which is then incorporated into the parameter estimation. This feedback mechanism ensures that likelihood distribution information is not lost but actively utilized to improve estimation precision.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20250265732A1Camera parameter calculation device, camera parameter calculation method, and non-transitory computer readable recording medium
Publication Date: 2025.08.21 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • US20250265732A1 patent drawing
  • US20250265732A1 patent drawing
  • US20250265732A1 patent drawing

AI summary

A camera parameter calculation device acquires an image taken by a camera, generates a heatmap representing a likelihood of image principal point at each pixel by inputting the acquired image to a learning model, and calculates a camera parameter of the camera on the basis of the generated heatmap, the learning model being trained by machine learning so as to cause an estimated image principal point indicated by a heatmap to approach a true value for the estimated image principal point.