Method of correcting projection background inconsistency in CT imaging

Abstract

The invention relates to a method of correcting projection background inconsistency in CT imaging, and specifically relates to a CT projection background cross-correlation registration method based on image grayscale information. The method comprises the following steps: (1) before acquisition of a sample CT projection image, acquiring a bright field image, and determining the spot center of the bright field image; (2) calculating a compensation function of the bright field image; (3) compensating the illumination of the bright field image; (4) compensating the illumination of the projection image; (5) calculating the actual offset between the background of the projection image and the background of the bright field image; and (6) performing image translation registration. A CT projection is registered using the principle of cross-correlation based on image grayscale information. The method has the advantages of no need to know the specific deflection parameter of a detector in advance, simple operation, and high computation efficiency.

Description

technical field [0001] The invention relates to a method for correcting inconsistent backgrounds of projection images in CT imaging, in particular to a background cross-correlation registration method for CT projection images based on image grayscale information. Background technique [0002] CT imaging technology can quickly and non-destructively detect the three-dimensional structure of objects, and has become an important means of characterizing the three-dimensional structure of materials. In the process of CT reconstruction, in order to avoid the impact of dust, defects or electronic noise on the detector on the CT projection image, bright field images and dark field images are often collected during the CT experiment process, and the background of the projection data is subtracted to improve the CT image. Image precision. High-precision CT image reconstruction requires that the X-ray source, the axis of the sample stage, and the detector remain relatively stationary d...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the technical problems of complex operation and large amount of calculation in the correction method of CT reconstruction image artifacts caused by inconsistency of the projection image background in the process of CT scan reconstruction, the present invention provides a method for correcting the inconsistency of the projection image background in CT imaging, This method is based on the principle of cross-correlation, does not need to know the specific parameters of the detector deflection in advance, and has the advantages of simple operation and high calculation efficiency

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