Point Spread Function Classification for Image Deblurring

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Solution Overview

Problem

Existing image deblurring techniques face challenges in accurately distinguishing and addressing motion blur and defocus blur, leading to difficulties in recovering latent sharp images and point spread functions from blurry images.

Innovation Solution

A method is developed to classify test images by building a classifier that distinguishes between motion blur and defocus blur features using structural properties of point spread functions, allowing for improved deblurring accuracy by identifying the appropriate point spread functions for subsequent processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single PSF kernel is assumed for the entire image, then the blind deconvolution problem is simplified, but the accuracy of recovering the latent sharp image and PSF kernel deteriorates when different areas have different blur characteristics

Engineering Contradiction:
ImprovePSF kernel assumptionVSAvoidPSF kernel and latent sharp image recovery accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the image into multiple regions of interest (ROIs), where each ROI is assumed to have its own PSF kernel. This segmentation allows different areas with different blur characteristics to be processed independently, resolving the contradiction between simplicity and accuracy. The image is divided into ROIs based on detected blur characteristics, enabling localized PSF estimation without requiring a single global PSF for the entire image.

Inventive Principle:
Principle #1Segmentation

2Productivity

If blur type is not classified, then the processing pipeline is simpler, but the deblurring performance deteriorates when motion blur and defocus blur coexist

Engineering Contradiction:
Improveprocessing efficiencyVSAvoiddeblurring accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary classification of blur types in each ROI before applying deblurring operations. By first identifying whether each region has motion blur, defocus blur, or no blur, the system can select appropriate deblurring algorithms in advance. This preliminary action enables optimized processing without requiring complex real-time decision-making during the deblurring process itself.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adapts its processing approach based on the detected blur characteristics in each ROI. Instead of using a fixed deblurring algorithm for the entire image, the system switches between different deblurring methods (motion blur correction, defocus blur correction, or none) based on the classified blur type in each region, enabling flexible and accurate processing.

Inventive Principle:
Principle #15Dynamics

3Extent of automation

If automatic PSF extraction is applied without classification, then the workflow is more automated, but the connection between PSF estimation and image processing algorithms becomes less meaningful

Engineering Contradiction:
ImprovePSF extraction automationVSAvoidconnection between PSF estimation and image processing
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback loop where the extracted PSF characteristics and blur classification information are fed back into the image processing stage. This feedback enables the processing algorithms to adapt their behavior based on the actual PSF properties detected in each ROI, creating a meaningful connection between estimation and processing. The system uses the classified blur types and extracted PSFs to guide subsequent deblurring operations, ensuring the processing algorithms are appropriately adapted to the specific characteristics of each region.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS9530079B2Point spread function classification using structural properties
Publication Date: 2016.12.27 NIKON CORP
  • US9530079B2 patent drawing
  • US9530079B2 patent drawing
  • US9530079B2 patent drawing

AI summary

A method for classifying a test image (16) includes the steps of building a classifier (300), and classifying the test image (16) with the classifier (300). After the test image (16) is classified, the test image (16) can be subsequently processed (e.g. deblurred) with improved accuracy. The classifier (300) can classify and distinguish between PSF features associated with motion blurred images, and PSF features associate with defocus blurred images. The classifier (300) can be built using a plurality of training images (304), and extracting one or more training features from each the training images (304). The PSF features can include image moments of the point spread function, and/or geometric features of the point spread function.