Learning Autofocus with Neural Networks for Single-Image Focus Positioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional autofocus systems struggle with adapting to different object characteristics, require multiple images for focus determination, and are inefficient in defining optimal 3D scanning areas, leading to potential sample damage and increased costs.

Innovation Solution

Utilizing trained models, particularly neural networks, to analyze captured images for rapid focus position determination, enabling precise focus prediction with minimal image acquisition and adaptability across various imaging systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional autofocus systems use multiple images to determine focus position, then measurement precision is improved, but loss of time and sample damage increase

Engineering Contradiction:
Improvefocus position determination accuracyVSAvoidtime for acquiring multiple images
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The neural network model is trained in advance on a large dataset of images with known focus positions. This preliminary training enables the model to predict focus position from a single image during actual operation, eliminating the need to acquire multiple images at runtime while maintaining high measurement precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of acquiring multiple physical images of the sample, the system uses a single image and processes it through a trained neural network model that has learned focus patterns from training data. The model creates a virtual representation of multiple focus states without requiring actual multiple image acquisitions.

Inventive Principle:
Principle #26Copying

2Measurement precision

If conventional autofocus systems acquire multiple images to determine focus position, then measurement precision is improved, but object-affected harmful factors increase

Engineering Contradiction:
Improvefocus position determination accuracyVSAvoidphototoxic effects on living cells
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The neural network model is pre-trained on extensive image data with known focus positions. During actual sample observation, only a single image needs to be acquired and processed by the trained model, dramatically reducing light exposure to living cells and eliminating phototoxic effects while maintaining accurate focus determination.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses a single captured image processed through a trained neural network that has learned focus characteristics from training data. This virtual analysis approach replaces the need for multiple physical image acquisitions, thereby protecting living samples from light-induced damage.

Inventive Principle:
Principle #26Copying

3Speed

If conventional autofocus systems use laser reflection method, then speed of focus determination is improved, but adaptability to different object characteristics deteriorates

Engineering Contradiction:
Improvefocus determination speedVSAvoidadaptability to different object characteristics
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The neural network model can be trained on diverse datasets representing different object types, imaging modalities, and conditions. By changing the training parameters and data distribution, the same model architecture adapts to different objects and systems, providing both speed and versatility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The neural network-based autofocus system is designed to be universal and can handle various object types, microscopy modalities (confocal, widefield, light-sheet), and imaging conditions. The single trained model serves multiple functions across different applications, replacing the need for object-specific calibration required by laser reflection methods.

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

4Measurement precision

If conventional autofocus systems scan large areas with multiple images, then measurement precision is improved, but loss of time and storage space increase

Engineering Contradiction:
Improvefocus position determination accuracyVSAvoidstorage space for image data
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The system extracts only the essential focus position information from a single image using the trained neural network model. Instead of storing and processing large quantities of image data from multiple scans, the model extracts the critical focus parameter directly, minimizing storage requirements while maintaining measurement accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3884657B1Learning autofocus
Publication Date: 2025.07.16 LEICA MICROSYSTEMS CMS GMBH
  • EP3884657B1 patent drawingFigure 1
  • EP3884657B1 patent drawingFigure 2
  • EP3884657B1 patent drawingFigure 3

AI summary

The invention relates to a method (500) and an apparatus (130; 210, 220, 230) for determining a focus position by means of trained models. The solutions from the prior art are disadvantageous because determining a focus position is slow or susceptible to errors. The method (500) according to the invention and the apparatus (130; 210, 220, 230) according to the invention improve solutions from the prior art by virtue of recording (510) at least one first image (310, 320), the image data of the at least one recorded first image (310, 320) depending on at least one first focus position when recording the at least one first image, and determining (520) a second focus position (340) on the basis of an analysis of the at least one recorded first image (310, 320) by means of a trained model (136).