Linear scanning CL reconstruction method based on projection visual angle weighting

Abstract

The invention provides a linear scanning CL reconstruction method based on projection visual angle weighting. The method comprises the following specific steps: 1) data collection: carrying out the CL linear scanning of a to-be-measured object, and obtaining projection data; 2) performing image primary reconstruction: performing image reconstruction on the projection data collected in the step 1) by using a filtered back projection algorithm to obtain reconstructed images under different visual angles; 3) determining a back projection weighting coefficient: determining a reference value of the layered images according to the reconstructed images at different view angles in the step 2), calculating dissimilarity between the layered images at different projection view angles according to the reference value, and determining the back projection weighting coefficient according to the dissimilarity and adjustment parameters alpha and beta; and 4) performing back projection reconstruction: performing back projection reconstruction by using the back projection weighting coefficient obtained in the step 3), thereby solving the problems of incomplete projection data, image limited angle artifacts, layered image blurring and the like caused by the fact that the plate-shaped part is not suitable for full-angle scanning, reducing layered image aliasing, and improving the quality of the reconstructed image.

Description

technical field [0001] The present invention relates to the field of image processing, in particular to a linear scanning CL reconstruction method based on projection angle weighting. Background technique [0002] Computed laminography (CL) is a non-destructive testing technology that effectively detects the internal structure information of objects. Compared with computed tomography (CT), it can solve the problems that exist when CT technology detects large plate-shaped components. It has been widely used in medical diagnosis, materials science, microelectronics, and archaeology due to the limited imaging space and impenetrable rays. Because CL projection data is incomplete and does not satisfy Tuy's exact reconstruction conditions, CL images have limited-angle artifacts and interlayer blurring. Therefore, it is of great practical significance to study effective CL reconstruction algorithms. [0003] At present, CL reconstruction algorithms are divided into four categories...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a linear scan CL reconstruction method based on projection angle weighting, which can be used for linear scan CL reconstruction, and is used to overcome the limitations of CT technology for plate-shaped component detection and the layering caused by CL scanning structures Image blur problem, which not only solves the limitation of detection of plate-like components but also improves the quality of reconstructed images

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