Camera Calibration Saddle Point Detection Across Shifted Image Regions

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing camera calibration methods face challenges in accurately detecting saddle points, particularly when they are located on the border between regions of interest, leading to reduced recall and increased computational complexity.

Innovation Solution

A method involving image shifting and re-shifting using machine learning, specifically an artificial neural network, to detect and align saddle points across multiple shifted images, leveraging a grid structure and non-maximum suppression to enhance detection accuracy and reduce computational time complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing camera calibration methods are used to detect saddle points, then the detection process can be completed, but the recall is reduced and computational complexity increases when saddle points are located on border regions

Engineering Contradiction:
Improvesaddle point detection recallVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The input image is divided into multiple regions of interest (ROIs), and each ROI is processed independently through the neural network. This segmentation allows the system to handle saddle points on borders more effectively by distributing the detection task across multiple smaller regions, improving recall while managing computational complexity through parallel processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent processes the image by creating multiple overlapping regions of interest, effectively adding a spatial dimension to the detection process. By evaluating the same image content from multiple overlapping regions, the system ensures that saddle points near borders are captured by at least one ROI, thereby improving detection recall without requiring a fundamentally more complex computational approach.

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

2Measurement precision

If multiple shifted images are processed to improve saddle point detection accuracy, then detection recall improves, but processing time increases

Engineering Contradiction:
Improvesaddle point detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary actions by creating multiple regions of interest with different shifts before the actual detection process. These pre-defined shifts are optimized to cover border regions effectively, ensuring that saddle points are captured in at least one ROI without requiring exhaustive processing of all possible shifts, thus balancing accuracy improvement with time efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Different regions of interest are created with local quality variations through different shifts and overlapping configurations. This allows the system to focus computational resources on regions where saddle points are more likely to be missed (border regions), improving overall detection accuracy while minimizing unnecessary processing in regions that are already well-covered.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4075384B1Methods and systems for determining pre-determined points in an input image
Publication Date: 2025.08.13 APTIV TECHNOLOGIES AG
  • EP4075384B1 patent drawingFigure 1A
  • EP4075384B1 patent drawingFigure 1B
  • EP4075384B1 patent drawingFigure 2

AI summary

A computer implemented method for determining pre-determined points in an input image comprises the following steps carried out by computer hardware components: applying a plurality of shifts to the input image to obtain a plurality of shifted images; detecting pre-determined points in each of the shifted images; re-shifting the detected pre-determined points; and determining the pre-determined points based on the re-shifted detected pre-determined points.