Three-dimensional digital volume image distortion measuring method

Abstract

The invention relates to a three-dimensional digital volume image distortion measuring method, which comprises the following steps of: (1) selecting scattered sampling points on a digital volume image before distortion; (2) determining a reference sub-volume and the dimension of a searched area; (3) performing three-dimensional image-related operation on the reference sub-volume and the searched area based on a three-dimensional Fast Fourier Transform method; (4) establishing an image gray three-dimensional summing table and an image energy three-dimensional summing table; (5) solving a three-dimensional zero-mean normalization cross correlation coefficient matrix by using the operational result in the step (3) and the three-dimensional summing tables; (6) calculating subvoxel displacement values of the sampling points by using a gradient-based three-dimensional subvoxel displacement location algorithm; (7) calculating accurate displacement values at all the sampling points according to the steps (3) to (6) so as to obtain a three-dimensional displacement field of the whole distorted volume image relative to the volume image before distortion; and (8) calculating a three-dimensional strain field of the digital volume image according to the Lagrangian strain tensor theory in mechanics of continuous media. The three-dimensional distortion of the digital volume image can be accurately and efficiently measured.

Description

technical field [0001] The invention relates to a measurement method, in particular to a deformation measurement method for quantitative analysis of three-dimensional digital volume images. Background technique [0002] The basic principle of the existing two-dimensional digital image correlation technology is to compare the digital image before deformation (reference image) and the image after deformation (deformation image), that is, to compare the reference image with the deformation image. Then a series of cross-correlation operations are performed to obtain the displacement field and strain field of the deformed image relative to the pre-deformed image. At present, the traditional two-dimensional digital image correlation method has become a classic experimental mechanics technology and has been widely used in many fields such as material mechanical behavior testing, micro-scale deformation measurement, micro-electro-mechanical system (MEMS) structure dynamic characteri...

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Problems solved by technology

The computational complexity of the above traditional digital volume correlation method has become the main obstacle restricting its further wide application, especially in the case of large sample statistical analysis, the computational efficiency of the traditional digital volume correlation method cannot meet the requirements at all

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