CN-116433785-B - Method, device and system for processing CT image ring artifact and storage medium

CN116433785BCN 116433785 BCN116433785 BCN 116433785BCN-116433785-B

Abstract

The embodiment of the invention provides a method, a device, a system and a storage medium for processing CT image ring artifacts, belonging to the technical field of image processing. The method comprises the steps of obtaining an original CT image, carrying out first filtering processing on the original CT image, extracting ring-shaped artifact images in the original CT image, carrying out first conversion processing on the ring-shaped artifact images to obtain first ring-shaped artifact conversion images, carrying out second filtering processing on the first ring-shaped artifact conversion images to obtain second ring-shaped artifact conversion images, carrying out second conversion processing on the second ring-shaped artifact conversion images to obtain third ring-shaped artifact conversion images, wherein the second conversion processing is the inverse process of the first conversion processing, and carrying out image subtraction processing on the original CT image and the third ring-shaped artifact conversion images to obtain target CT images without ring-shaped artifacts. The invention effectively improves the accuracy of ring artifact processing, can obtain the artifact removed image with higher quality, has complete image edge preservation and high signal to noise ratio.

Inventors

WANG HONGBIN
PAN SHUXIN
MA DELONG
WANG YANJUN
LIU WENQIANG
CUI JIAN

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260505
Application Date: 20211231

Claims (10)

1. A method for processing CT image ring artifacts, comprising: acquiring an original CT image with ring artifacts; Performing first filtering processing on the original CT image, and extracting an annular artifact image in the original CT image; Performing first conversion processing on the ring-shaped artifact image to obtain a first ring-shaped artifact conversion image, and performing second filtering processing on the first ring-shaped artifact conversion image to obtain a second ring-shaped artifact conversion image; performing second conversion processing on the second ring-shaped artifact conversion image to obtain a third ring-shaped artifact conversion image, wherein the second conversion processing is the inverse process of the first conversion processing; And performing image subtraction processing on the original CT image and the third ring artifact conversion image to obtain a target CT image without ring artifacts.
2. The method according to claim 1, wherein the first filtering process is a non-local mean filtering process; performing a first filtering process on the original CT image, and extracting a ring artifact image in the original CT image, including: performing non-local mean filtering processing on the original CT image to obtain a background image which does not comprise ring artifacts; And performing image subtraction processing on the original CT image and the background image to obtain an annular artifact image in the original CT image.
3. The method according to claim 1, wherein the first conversion process is a polar coordinate transformation; Performing a first conversion process on the ring artifact image to obtain a first ring artifact converted image, including: performing polar coordinate transformation on each pixel of the ring-shaped artifact image, and converting rectangular coordinates of each pixel into polar coordinates in a polar coordinate system with an isocenter as an origin; And configuring each pixel of the ring artifact image into the polar coordinate system based on the polar coordinates so as to convert the ring artifact image into a strip artifact image, and taking the obtained strip artifact image as a first ring artifact conversion image.
4. A method for processing a cyclic artifact in a CT image according to claim 3, wherein performing a second filtering process on the first cyclic artifact converted image to obtain a second cyclic artifact converted image comprises: Constructing a one-dimensional filter in the horizontal axis direction of the polar coordinate system, wherein the convolution kernel matrix of the one-dimensional filter is n multiplied by m; And sequentially carrying out Gaussian low-pass filtering processing on each pixel in the first cyclic artifact conversion image along the horizontal axis direction of the polar coordinate system by using the one-dimensional filter so as to obtain a blurred strip artifact image serving as a second cyclic artifact conversion image.
5. The method according to claim 4, wherein constructing a one-dimensional filter of the polar coordinate system in the transverse axis direction comprises: And acquiring the width of the strip artifact in the first annular artifact conversion image, and determining that n is 3 when the width of the strip artifact is smaller than a threshold value.
6. The method according to claim 4, wherein the second conversion process is rectangular transformation; performing a second conversion process on the second ring artifact converted image to obtain a third ring artifact converted image, including: performing rectangular coordinate transformation on each pixel of the second ring-shaped artifact conversion image, and converting the polar coordinates of each pixel into rectangular coordinates in a rectangular coordinate system; And configuring each pixel of the second ring artifact conversion image into the rectangular coordinate system based on the rectangular coordinate so as to convert the blurred stripe artifact image into a blurred ring artifact image, and taking the obtained blurred ring artifact image as a third ring artifact conversion image.
7. A device for processing CT image ring artifacts, comprising: a data acquisition module configured to acquire an original CT image with ring artifacts; The image processing module is configured to perform first filtering processing on the original CT image and extract a ring-shaped artifact image in the original CT image; the first image conversion module is configured to perform first conversion processing on the ring-shaped artifact image to obtain a first ring-shaped artifact conversion image, and perform second filtering processing on the first ring-shaped artifact conversion image to obtain a second ring-shaped artifact conversion image; A second image conversion module configured to perform a second conversion process on the second ring artifact converted image to obtain a third ring artifact converted image, the second conversion process being an inverse of the first conversion process; And the artifact removing module is configured to perform image subtraction processing on the original CT image and the third ring artifact conversion image to obtain a target CT image without ring artifacts.
8. A system for processing CT image ring artifacts, comprising: A CT scanning device for CT scanning the target to acquire an original CT image, and The CT image ring artifact processing apparatus according to claim 7.
9. An electronic device, comprising: A memory storing computer readable instructions; A processor configured to read computer readable instructions stored in a memory to perform the method of processing CT image ringing artifacts of any one of claims 1 to 6.
10. A machine-readable storage medium having instructions stored thereon, which when executed by a processor cause the processor to be configured to perform the method of processing CT image ringing artifacts of any one of claims 1 to 6.

Description

Method, device and system for processing CT image ring artifact and storage medium Technical Field The present invention relates to the field of image processing technologies, and in particular, to a method for processing a CT image ring artifact, a device for processing a CT image ring artifact, a system for processing a CT image ring artifact, and a machine-readable storage medium. Background In geologic image analysis, CT (Computed Tomography, electronic computed tomography) electron microscopy is a common lithology detection method. Due to the factors of defects of detector pixel elements, errors of ray intensity receiving elements, nonlinear response of an instrument to a ray energy spectrum and the like, ring artifacts often appear in a CT image, the ring artifacts are tightly overlapped with a detected sample image, and a series of concentric circles with the center of the image as a circle center and different radiuses are displayed on the image. The existence of the ring artifact greatly reduces the quality of the image, brings great trouble to further processing and analysis such as image measurement, identification, noise processing, image segmentation and the like, and the industrial CT scanning image containing the ring artifact directly influences the correct diagnosis of lithology analysis. Disclosure of Invention An object of an embodiment of the present invention is to provide a method, an apparatus, a system and a storage medium for processing CT image ring artifacts, so as to solve the above-mentioned problems. In order to achieve the above object, in a first aspect of the present invention, there is provided a method for processing a CT image ring artifact, including: acquiring an original CT image with ring artifacts; Performing first filtering processing on the original CT image, and extracting an annular artifact image in the original CT image; Performing first conversion processing on the ring-shaped artifact image to obtain a first ring-shaped artifact conversion image, and performing second filtering processing on the first ring-shaped artifact conversion image to obtain a second ring-shaped artifact conversion image; performing second conversion processing on the second ring-shaped artifact conversion image to obtain a third ring-shaped artifact conversion image, wherein the second conversion processing is the inverse process of the first conversion processing; And performing image subtraction processing on the original CT image and the third ring artifact conversion image to obtain a target CT image without ring artifacts. Optionally, the first filtering process is a non-local mean filtering process, and the first filtering process is performed on the original CT image to extract the ring artifact image in the original CT image, including: performing non-local mean filtering processing on the original CT image to obtain a background image which does not comprise ring artifacts; And performing image subtraction processing on the original CT image and the background image to obtain an annular artifact image in the original CT image. Optionally, the first conversion process is polar coordinate conversion, and the first conversion process is performed on the ring artifact image to obtain a first ring artifact converted image, including: performing polar coordinate transformation on each pixel of the ring-shaped artifact image, and converting rectangular coordinates of each pixel into polar coordinates in a polar coordinate system with an isocenter as an origin; And configuring each pixel of the ring artifact image into the polar coordinate system based on the polar coordinates so as to convert the ring artifact image into a strip artifact image, and taking the obtained strip artifact image as a first ring artifact conversion image. Optionally, performing a second filtering process on the first ring artifact converted image to obtain a second ring artifact converted image, including: Constructing a one-dimensional filter in the horizontal axis direction of the polar coordinate system, wherein the convolution kernel matrix of the one-dimensional filter is n multiplied by m; And sequentially carrying out Gaussian low-pass filtering processing on each pixel in the first cyclic artifact conversion image along the horizontal axis direction of the polar coordinate system by using the one-dimensional filter so as to obtain a blurred strip artifact image serving as a second cyclic artifact conversion image. Optionally, constructing a one-dimensional filter of the polar coordinate system in the transverse axis direction includes: And acquiring the width of the strip artifact in the first annular artifact conversion image, and determining that n is 3 when the width of the strip artifact is smaller than a threshold value. Optionally, the second conversion process is rectangular coordinate conversion, and the second conversion process is performed on the second ring artifact conversion image to o