A deformation measurement method and system based on feature matching and image correction

By employing feature matching and two-stage image correction, the problems of speckle loss of correlation and perspective distortion in traditional DIC technology under large-angle rotation are solved, enabling high-precision full-field deformation measurement under single-camera settings, which is suitable for complex working conditions such as high-speed rotating gears.

CN122175881APending Publication Date: 2026-06-09INST OF MECHANICS CHINESE ACAD OF SCI
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
INST OF MECHANICS CHINESE ACAD OF SCI
Filing Date
2026-02-11
Publication Date
2026-06-09

AI Technical Summary

Technical Problem

Traditional two-dimensional digital image correlation technology fails to measure under large-angle in-plane rotation or camera movement due to speckle loss of correlation and perspective distortion. Existing improved solutions cannot achieve full-field, continuous, and high-precision deformation measurement under ordinary single-camera settings.

Method used

A method based on feature matching and two-stage image correction is adopted. First, feature points are extracted and matched using the SURF algorithm, and the affine transformation matrix is ​​calculated to eliminate in-plane rotation. Then, perspective distortion is eliminated using the projection transformation matrix. Finally, digital image correlation calculation is performed to achieve full-field deformation measurement.

Benefits of technology

It achieves high-precision, continuous deformation measurement across the entire 360° angular range, making it particularly suitable for dynamic scenarios such as high-speed rotating gears. The measurement error can be reduced to within 10%, significantly improving the system's simplicity and environmental robustness.

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Abstract

This invention provides a deformation measurement method and system based on feature matching and two-stage image correction. The core of this deformation measurement method lies in employing a two-stage image geometric correction mechanism: First, based on SURF feature matching, an affine transformation matrix is ​​calculated to perform preliminary correction on deformed images exhibiting large-angle rigid body motion, eliminating in-plane rotation and translation. Then, based on SURF feature matching again, a projection transformation matrix is ​​calculated to perform fine correction on the pre-corrected image, compensating for perspective distortion caused by the camera optical axis not being perpendicular to the plane of the measured object. Finally, digital image correlation calculations are performed on the corrected image to obtain an accurate full-field deformation field. The deformation measurement system includes an image acquisition unit, an image processing unit, and an output unit. This invention fundamentally solves the measurement failure problem caused by geometric miscorrelation and speckle miscorrelation in traditional two-dimensional digital image correlation technology under large-angle rotation or camera motion.
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Citation Information

Patent Citations

  • Visual deformation measurement system based on monocular three dimensions

    CN120141329A