A method for testing the multi-axis repeatability accuracy of X-ray devices

Abstract

This invention relates to the field of industrial CT applications, and particularly to a method for CT image reconstruction. Using a specific test object, an X-ray device can clearly acquire a projected image of the test object, which is then used as a standard image. The device then moves four axes to random positions and returns to those positions, acquiring another projected image to calculate a residual map relative to the standard image. To measure the offset value corresponding to this residual map, a set of standard offset residual maps is pre-calculated for each axis. Through image comparison, deviations at the 1µm level can be analyzed and identified, which is sufficient to meet the repeatability requirements of CT image reconstruction.

Description

Technical Field

[0001] This invention relates to the field of industrial CT applications, and particularly to the field of CT image reconstruction. Background Technology

[0002] For AXI equipment, the repeatability of the four axes carrying the X-ray source and detector directly affects the quality of CT image reconstruction. Poor repeatability will result in artifacts in the reconstructed CT images. The quality of the CT image reconstruction, in turn, directly impacts the detection accuracy of the AXI equipment. Therefore, verifying the repeatability of these four axes is an indispensable function for AXI equipment.

[0003] In existing technologies, laser interferometers can achieve repeatability accuracy at the 1μm level, but they can only test a single bearing axis at a time, and such instruments are relatively expensive. Another method, which uses a CCD color camera with a high-resolution lens and employs image visual analysis to detect repeatability accuracy, is difficult to achieve 1μm, generally only reaching 3-4μm. Therefore, a high-precision multi-axis accuracy testing method capable of achieving 1μm testing accuracy is needed to fill the market gap.

[0004] This invention provides a practical and feasible solution for high-precision detection of multi-axis repeatability. Summary of the Invention

[0005] One objective of this invention is to provide a solution for high-precision detection of multi-axis repeatability.

[0006] To address the aforementioned technical problems, the embodiments of the present invention provide the following technical solutions:

[0007] This invention provides a method for testing the multi-axis repeatability accuracy of an X-ray device, which includes the following steps:

[0008] Step 1: When the detection device is in the first position, acquire a standard projection image of the test object and perform flat field correction;

[0009] Step 2: When the detection device moves to a random coordinate position and returns to the first position, a random projection image of the test object is acquired;

[0010] Step 3: Calculate the residual plot of the random projection plot relative to the standard projection plot, and perform normalization processing;

[0011] Step 4: Compare the residual plot with the standard residual plot set used to provide standard offset values ​​to obtain the offset of the X and Y axes of the detection device;

[0012] Step 5: Repeat steps 1 to 5 N times to obtain N offsets;

[0013] Step 6: Determine the maximum value among the N offsets as the repeatability accuracy test result of the detection device.

[0014] Optionally, according to the X-ray device multi-axis repeatability accuracy testing method, before performing step four, the method further includes:

[0015] Flat field correction is performed on the standard projection map and the random projection map.

[0016] Optionally, according to the X-ray device multi-axis repeatability accuracy test method, the flat-field correction of the standard projection image and the random projection image includes:

[0017] Acquire dark field images;

[0018] After removing the test object, a bright field image was acquired;

[0019] Based on the acquired bright field and dark field images, flat field correction is performed.

[0020] Optionally, according to the X-ray device multi-axis repeatability accuracy test method, the detection device includes: a detector and a radiation source mounted on different moving bearings;

[0021] The steps for obtaining the standard projection image when the acquisition and detection device is in the first position specifically include:

[0022] The detector and the radiation source are moved to a position corresponding to the first position, so that the X-ray device passes through the detection equipment to generate the standard projection image.

[0023] Optionally, according to the multi-axis repeatability accuracy test method for X-ray devices, the standard offset value residual map set is obtained by the following method:

[0024] Step 1: When the detection device is in the first position, acquire a standard projection image of the test object and perform flat field correction;

[0025] Step 2: Move the detection device along a preset direction and a preset distance;

[0026] Step 3: Acquire the offset projection map of the detection device in its current state and perform flat-field correction;

[0027] Step 4: Calculate the residual map of the offset projection map relative to the standard projection map;

[0028] Step 5: Normalize the residual map and establish a correspondence with the corresponding movement axis offset value;

[0029] Step 6: Repeat steps 2 to 5 until the preset conditions are met, and obtain N offset values ​​and the corresponding residual map.

[0030] Step 7: Collect the offset values ​​and corresponding residual plots, and generate a standard offset value residual plot group file.

[0031] Optionally, according to the X-ray device multi-axis repeatability accuracy test method, the preset distance is 1 micrometer; the preset condition is that the sum of the preset distances reaches N micrometers.

[0032] To address the above problems, embodiments of the present invention provide a multi-axis repeatability accuracy testing system for X-ray devices, wherein the projection adjustment system includes:

[0033] The standard projection image acquisition module is used to acquire a clear "well" shaped image that the X-ray device can collect through the "well" shaped fixture;

[0034] The flat field correction module is used to acquire a bright field image and a dark field image, correct the image gain, and eliminate noise.

[0035] The residual plot information analysis module is used to calculate the residual plot of the projection plot to be tested relative to the standard projection plot, and perform normalization processing. The obtained residual plot is compared with the standard X and Y axis offset residual plot to obtain the offset of the X and Y axes.

[0036] To address the above problems, embodiments of the present invention provide a CT imaging testing system, specifically comprising:

[0037] An X-ray emitting device for emitting the X-rays includes upper X-ray and upper Y-ray bearing detectors and lower X-ray and lower Y-ray bearing ray sources.

[0038] A projection image capture device, used to acquire any of the projection images described in the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual map group acquisition method;

[0039] A control device for controlling the coordinate positions of the upper X-axis, upper Y-axis, and lower X-axis and lower Y-axis in the multi-axis repeatability accuracy test method and the standard offset value residual plot acquisition method of the X-ray device.

[0040] The device under test, such as a tungsten filament carrier, is used for experimental testing.

[0041] To address the above problems, embodiments of the present invention provide an electronic device, including:

[0042] At least one processor; and,

[0043] A memory communicatively connected to the at least one processor; wherein,

[0044] The memory stores instructions that can be executed by the at least one processor, which enables the at least one processor to perform any one of the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual map group acquisition method.

[0045] To address the aforementioned problems, embodiments of the present invention provide a computer program product containing program code. When the computer program product is run on an electronic device, the electronic device executes any one of the methods described in the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual map group acquisition method.

[0046] In this embodiment of the invention, a grid-shaped tungsten wire fixture is used as the detection object. The carrier detector and the carrier X-ray source are moved to a suitable position (approximately vertically above and below) so that the X-ray device can clearly acquire the grid-shaped projection image, which is then used as the standard image. The four axes are then moved to random positions and returned to their original positions, and the projection images are acquired again to calculate the residual map relative to the standard image. To measure the offset value corresponding to this residual map, a set of standard offset residual maps is pre-calculated for each axis. By comparing the images, deviations at the 1µm level can be analyzed and identified, which is sufficient to meet the repeatability accuracy requirements of CT image reconstruction.

[0047] Using the methods described above, high-precision multi-axis precision testing equipment can achieve a testing accuracy of 1μm. Attached Figure Description

[0048] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0049] Figure 1 This is a schematic diagram of a tungsten wire carrier structure provided in an embodiment of the present invention;

[0050] Figure 2 This is a flowchart of the operation of an X-ray device system provided in an embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the X-ray device flat field correction process provided in an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of the process for obtaining standard offset value residual plots provided in an embodiment of the present invention;

[0053] Figure 5 This is a schematic flowchart of a multi-axis repeatability accuracy testing method for an X-ray device provided in an embodiment of the present invention;

[0054] Figure 6 This is a schematic diagram of the CT imaging testing equipment provided in an embodiment of the present invention;

[0055] Figure 7 This is a schematic diagram of the structure of the projection image acquisition device provided in an embodiment of the present invention;

[0056] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention;

[0057] Figure 9 This is a curve diagram of converting pixel values ​​of a projection image to grayscale values ​​provided in an embodiment of the present invention;

[0058] Figure 10 This is a projection image before flat-field correction provided in an embodiment of the present invention;

[0059] Figure 11 This is a projection image after flat-field correction provided in an embodiment of the present invention;

[0060] Figure 12 This is a residual image of the X-axis 1µm offset under the detection device provided in this embodiment of the invention;

[0061] Figure 13 This is a residual image of the X-axis 2µm offset under the detection device provided in this embodiment of the invention;

[0062] Figure 14 This is a residual image of the 1µm offset along the Y-axis provided in the embodiment of the present invention.

[0063] Figure 15 This is a residual image of the 2µm offset along the Y-axis provided in the embodiment of the present invention.

[0064] Figure 16 This is a residual image of the X and Y axis offset of 0µm under the detection device provided in the embodiment of the present invention;

[0065] Figure 17 This is a residual map of the X-axis offset of 0µm and the Y-axis offset of 2µm under the detection device provided in this embodiment of the invention. Detailed Implementation

[0066] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0068] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0069] Figure 1 The illustration shows a tungsten wire tooling provided in an embodiment of the present invention. The tungsten wire tooling is a cubic structure containing four tungsten wires.

[0070] The upper part of the tungsten wire fixture includes two tungsten wires at mutually perpendicular angles. Both tungsten wires are parallel to the nearest adjacent edge of the cube. The lower part includes two tungsten wires, also at mutually perpendicular angles and parallel to the nearest adjacent edge of the cube. The two sets of tungsten wires are diagonally located near the two apexes of the same diagonal line and are parallel to each other. The tungsten wire fixture uses X-rays to project an image in the shape of a grid. The tungsten wire fixture serves as the detection object in this embodiment of the invention.

[0071] The example projection diagram provided in this embodiment of the invention has a window width of 2000 and a window level of 4500, and then uses, as follows Figure 9 Convert the image to grayscale for display.

[0072] Figure 2 This diagram illustrates an X-ray device system operation flowchart provided by an embodiment of the present invention, specifically including:

[0073] 21. System initialization.

[0074] The system returns to its initial state, restoring the positions of the X and Y axes as initially set, namely the positions of the detectors on the upper X and Y axes and the radiation sources on the lower X and Y axes.

[0075] The initialization position is the first position, and after initialization, the system can acquire a standard projection image.

[0076] 22. Collect standard projection images and perform leveling correction.

[0077] The projection image is acquired by an X-ray device, which consists of a radiation source, a detector, and upper and lower X-axis and Y-axis that support the radiation source and detector. The detector is carried by the upper X-axis and Y-axis, and the radiation source is carried by the lower X-axis and Y-axis.

[0078] Move the X-axis and Y-axis onboard detectors and the X-axis and Y-axis onboard X-ray sources to appropriate positions so that the X-ray device can capture a clear "well" shaped image through the "well" shaped jig, and the image can be used as a standard projection image.

[0079] In this embodiment of the invention, when performing the flat field correction, it is necessary to acquire a bright field image and a dark field image. When acquiring the bright field image, the tungsten wire tool needs to be removed.

[0080] 23. Collect 1-20μm offset residual maps.

[0081] By controlling the positions of the carrier detectors and the X-ray source on the upper and lower X and Y axes, offset projection maps are acquired, and offset residual maps corresponding to the current offset X and Y axis positions are calculated based on the offset projection maps and the standard projection maps, and corresponding standard offset value residual map groups are generated. This invention is an embodiment that only acquires offset residual maps of 1-20μm, but is not limited to this range.

[0082] In some embodiments, the acquisition accuracy of the offset residual map is 0.5 μm.

[0083] 24. Perform multi-axis repeatability accuracy testing based on the offset residual plot set.

[0084] The X-ray device is divided into upper X and Y axes and lower X and Y axes. In the multi-axis repeatability accuracy test, the repeatability accuracy of the four axes (upper and lower X and Y) needs to be tested in two groups. Each group tests the X and Y axes. Each time, any group of X and Y axes is randomly moved to any coordinate position, and a projection image of the position is collected. The position offset residual image is calculated by comparing the position projection image with the standard projection image, and compared with the offset residual image group to obtain the offset of the X and Y axes of this group.

[0085] This invention uses a set of offset residual maps (1-20 μm) on the current X-ray equipment as a benchmark. When the system performs accuracy tests, the offset residual maps can be used to quickly determine the current axis offset, making it convenient for users to make adjustments.

[0086] Specifically, a grid-shaped tungsten wire fixture is designed. The upper X and Y axes (carrying the detector) and the lower X and Y axes (carrying the X-ray source) are moved to suitable positions (close to the vertical top and bottom) so that the X-ray device can clearly acquire the grid-shaped projection image, which is then used as the standard image. The four axes are then moved to random positions and returned to their original positions, and the projection image is acquired again to calculate the residual map relative to the standard image. To measure the offset value corresponding to this residual map, a set of standard offset residual maps is pre-calculated for each axis. By comparing the images, deviations at the 1µm level can be analyzed and identified, which is sufficient to meet the repeatability accuracy requirements of CT image reconstruction.

[0087] The aforementioned flat-field correction is to correct some inconsistencies on the sensor chip.

[0088] Ideally, when imaging a uniform target, the gray values ​​of all pixels in the acquired image should theoretically be the same. However, in the actual projected image, the values ​​of individual pixels often differ significantly.

[0089] For X-ray devices, the following are some common reasons for significant differences in imaging:

[0090] First, the carrier detector is damaged, and the X-ray photons received by the carrier detector are not uniform;

[0091] Second, the background noise present in the carrier detector affects the imaging effect;

[0092] Third, the hardware of the carrier transmitter is damaged, resulting in no X-ray emission or insufficient quantity or quality of emitted X-rays;

[0093] Fourth, the X-ray focus setting, exposure conditions, and exposure time settings are unreasonable;

[0094] Fifth, there is a mismatch between the detector and the image processing algorithm;

[0095] During normal CT image acquisition, the most common problem is that the detector receives X-ray photons unevenly and there is background noise in the detector. We need to perform flat field correction to eliminate noise and correct the image gain.

[0096] The flat field correction formula is as follows:

[0097]

[0098] For a single imaging unit, its corresponding gray value has a linear relationship with the incident light intensity. Different incident light slopes result in different image effects. The flat field correction mechanism makes the incident light slope the same by changing the signal gain and offset.

[0099] Figure 3 This invention illustrates a flowchart of the X-ray device planar calibration process provided in an embodiment of the invention, specifically including:

[0100] 221. Dark field correction: Obtain the system's dark field pixel values ​​(take the average value).

[0101] Acquire dark-field images from the X-ray device image acquisition system, as well as the dark-field pixel values.

[0102] In some embodiments, due to differences in the signal strength and offset received by the detector, the pixel values ​​in different regions of the dark field image are somewhat different. Therefore, the average value of the entire region is taken as the dark field pixel value of the X-ray device image acquisition system.

[0103] 222. Bright field correction: Obtain a reference image for flat field correction.

[0104] Obtain a bright-field reference image for flat field correction, and calculate the corresponding pixel values ​​based on the image.

[0105] In this embodiment of the invention, a reference image for flat field correction is obtained by imaging a uniform light field. This image is required in principle to be illuminated by a uniform light field, with the same time as the dark background image, and the illumination level of the illumination field is as close as possible to the saturated illumination conditions.

[0106] 223. Based on the bright field correction and dark field correction data, obtain an image with appropriate grayscale.

[0107] By comparing the images acquired after dark field correction and bright field correction, and multiplying the subtracted data by a reasonable value, an image with appropriate grayscale can be obtained without adversely affecting image processing.

[0108] The traditional flat-field correction method is the "two-point correction method," which assumes that the detector response is linear. First, an exposure is performed on the dark field to obtain the offset of each pixel; then, an image is taken of a uniformly grayscale object under uniform lighting conditions to obtain a uniform-field image, which makes all pixels in the image close to their maximum grayscale value; finally, the dark field image is subtracted from the bright field image, and the image gain is corrected using a relative calibration method.

[0109] The projection image before flat field correction Figure 10 There is hexagonal noise and uneven brightness.

[0110] Based on the above-described flat-field correction method, the projected image after flat-field correction Figure 11 Hexagonal noise is eliminated, and brightness is uniform.

[0111] However, the flat field correction method has certain limitations and is greatly affected by ambient temperature and light. Therefore, it can only achieve the maximum effect when the working environment does not change much. The equipment applicable to the embodiments of the present invention is an X-ray device, which is in a relatively simple environment with fewer influencing factors. Therefore, the flat field correction method can be applied.

[0112] Figure 4 This diagram illustrates a flowchart of a method for obtaining standard offset value residual plots according to an embodiment of the present invention, specifically including:

[0113] 231. Set the system initialization position to 0μm.

[0114] 232. Determine if the current position is less than or equal to 20μm.

[0115] Determine whether the current position of the detection device along the X and Y axes has moved more than 20 μm, and proceed to the next step based on the determination result.

[0116] 233. Collect residual plots; process ends.

[0117] When the system determines that the X and Y axis movement of the detection device is greater than 20 μm, it generates a corresponding set of standard offset residual maps based on the collected residual maps and ends the process.

[0118] The residual diagram corresponds one-to-one with the X and Y axis movement positions of the detection device.

[0119] 234. Move the selected detection device bearing axis to the specified offset value.

[0120] First, select one of the bearing axes in the detection device and control that axis to move a preset distance in a predetermined direction.

[0121] Optionally, the system can select two axes in the detection device to move simultaneously to collect projected image data under different conditions.

[0122] For example, in some embodiments, the X-axis of the detection device is tested first, and the preset direction of movement is to the right. The system will then collect image data for every micrometer of movement of the axis.

[0123] 235. Acquire offset projection images and perform flat field correction.

[0124] Acquire offset projection images of the positions after X and Y axis movement, and perform flat-field correction on the projection images. The flat-field correction method is as follows: Figure 3 As stated above.

[0125] 236. Calculate the residual image between the offset image and the standard image.

[0126] Based on the offset projection map acquired in the aforementioned steps, and... Figure 2 The standard projection diagram described herein is used to calculate the offset residual diagram of the current position.

[0127] 237. Normalize the residual plot.

[0128] Based on the residual image, it is normalized. The normalization formula is as follows: max is 255, min is 0, src represents the pixel value of the original image, and dst represents the pixel value of the calculated image.

[0129]

[0130] 238. Output the corresponding offset value and the corresponding offset residual plot.

[0131] Record the offset value corresponding to the offset residual map, and save the offset residual maps of the X and Y axis positions and their corresponding offset values ​​to the storage device.

[0132] 239. The offset value is increased by 1μm.

[0133] The system increments the position data of the corresponding axis by 1 μm, sends it to a comparator to compare whether the data is greater than 20 μm, and continues this loop until the position value is greater than 20 μm.

[0134] For example, following the above process, offset residual maps of 1-20µm are collected for the four axes: upper X, upper Y, lower X, and lower Y.

[0135] In some other embodiments, the offset value is set to 1.5 μm, and the smaller the offset value is set, the more accurate the confirmation of the image offset will be.

[0136] Figure 12 , Figure 13 , Figure 14 , Figure 15 These are examples of offset residual maps of the X and Y axes offset by a specified distance under a detection device in some embodiments and experimental cases.

[0137] Figure 5 A schematic diagram of the multi-axis repeatability accuracy test process in an embodiment of the present invention is shown. Specifically, it includes:

[0138] 241. Randomly move a set of X and Y axes to any position within the test area.

[0139] The X-ray device is divided into two groups of X and Y axes, one above the other. The system can randomly select one group as the test movement axis and can move to any position in the test area.

[0140] 242. Acquire projection images and perform flat field correction.

[0141] The projection images of the X and Y axis positions are acquired and flat field correction is performed.

[0142] 243. Calculate the residual plot and perform normalization.

[0143] The system uses the collected projection map of the current location, and Figure 2 The standard projection diagram is used to calculate the current positions of the X and Y axes and then normalize them.

[0144] 244. Compare with the aforementioned offset residual plot to obtain the offsets of the X and Y axes.

[0145] Based on the obtained offset residual map group and the offset residual map of the current position, the offset value of the current position is obtained by comparison.

[0146] 245. Return the X and Y axes to their original positions.

[0147] The moved axis returns to the system's initial position, and the number of tests is accumulated.

[0148] 246. Determine if the test has been repeated 30 times.

[0149] Check if the current loop count is greater than 30. If it is not greater than 30, return to the loop and continue testing.

[0150] 247. Calculate the maximum offset of the X and Y axes and output the test results.

[0151] In some embodiments, repeatability accuracy tests were performed on the four axes (X and Y) following the above procedure. Figure 16 and Figure 17 Example images for actual testing.

[0152] The multi-axis repeatability accuracy test method for the aforementioned X-ray device involves using a grid-shaped tungsten wire fixture as the probe object. The carrier detector and carrier X-ray source are moved to a suitable position (approximately vertically up and down) so that the X-ray device can clearly acquire the grid-shaped projection image, which is then used as the standard image. Next, the four axes are moved to random positions and then returned to their original positions. The projected images are then acquired again to calculate the residual map relative to the standard image. To measure the offset value corresponding to this residual map, a set of standard offset residual maps is pre-calculated for each axis. Through image comparison, deviations at the 1µm level can be analyzed and identified, which meets the repeatability accuracy requirements for CT image reconstruction.

[0153] Figure 6 The present invention illustrates a CT imaging testing system, which specifically includes: an X-ray emitting device 310, a projection image acquisition device 320, a control device 330, and a device under test 340.

[0154] X-ray emitting device 310, which is used to emit the X-rays, includes upper X-ray and upper Y-ray bearing detectors and lower X-ray and lower Y-ray bearing ray sources;

[0155] The projection image acquisition device 320 is used to acquire any projection image described in the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual map group acquisition method.

[0156] The control device 330 is used to execute the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual map group acquisition method, and control the movement of the bearing shaft according to the bearing shaft movement mode described in the method;

[0157] Device under test 340, such as Figure 1 The tungsten filament carrier described herein is used for experimental testing; the test object can also be other objects, and... Figure 1 The material of the tungsten filament carrier described in the text is similar to that of the object.

[0158] A simple CT imaging testing system, composed of the X-ray emitting device, the projection image acquisition device, the control device, and the device under test, can perform any one of the steps in the X-ray device multi-axis repeatability accuracy testing method and the standard offset value residual map group acquisition method described in this invention.

[0159] Figure 7 The diagram illustrates the structure of a projection image acquisition device in a multi-axis repeatability testing system provided by an embodiment of the present invention. The system projection image acquisition module includes: a standard projection image acquisition module 321, a flat field correction module 322, and a residual image information analysis module 323.

[0160] The standard projection image acquisition module 321 is used to acquire a clear "well" shaped image that the X-ray device can collect through the "well" shaped fixture;

[0161] The flat field correction module 322 is used to acquire a bright field image and a dark field image, correct the image gain, and eliminate noise.

[0162] The residual map information analysis module 323 is used to calculate the residual map of the projection map to be tested relative to the standard projection map, and perform normalization processing. The obtained residual map is compared with the standard X and Y axis offset residual map to obtain the offset of the X and Y axes.

[0163] The projection image acquisition device mainly includes a standard projection image acquisition module, a flat field correction module, and a residual image information analysis module. Using these modules, the projection images required in the X-ray device multi-axis repeatability accuracy test method and the standard offset value residual image group acquisition method can be realized.

[0164] As another aspect of this invention, an embodiment of the invention provides an electronic device. Please refer to... Figure 8 The chip 400 includes one or more processors 410 and memory 420. Among them, Figure 8 Take a processor 410 as an example.

[0165] The processor 410 and the memory 420 can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0166] The memory 420, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the hardware driving method in the embodiments of the present invention. The processor 410 executes the hardware driving methods of the above embodiments, or the various functional applications and data processing of the hardware driving devices of the above embodiments, by running the non-volatile software programs, instructions, and modules stored in the memory 420.

[0167] Memory 420 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 420 may optionally include memory remotely located relative to processor 410, which can be connected to processor 410 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0168] The program instructions / modules are stored in the memory 420. When executed by one or more processors 410, they execute the hardware driver method in any of the above method embodiments. For example, they execute the hardware driver methods of the above embodiments, or various functional applications and data processing of the hardware driver devices of the above embodiments.

[0169] This invention also provides a non-transitory computer-readable storage medium storing computer-executable instructions for causing a chip to execute the hardware driving method described above.

[0170] This invention provides a computer program product, which includes a computer program stored on a non-volatile computer-readable storage medium. The computer program includes program instructions, which, when executed by a chip, cause the chip to perform the hardware driving method described above.

[0171] In summary, by moving the carrier detector and carrier X-ray source to a suitable position (approximately vertically up and down), the X-ray device can clearly acquire a "grid" projection image, which is then used as the standard image. Next, the four axes are moved to random positions, then returned to those positions, and another projection image is acquired to calculate the residual map relative to the standard image. To measure the offset value corresponding to this residual map, a set of standard offset residual maps is pre-calculated for each axis. Through image comparison, deviations at the 1µm level can be analyzed and identified, meeting the repeatability accuracy requirements of CT image reconstruction.

[0172] The device or equipment embodiments described above are merely illustrative. The unit modules described as separate components may or may not be physically separate. The components shown as module units may or may not be physical units; that is, they may be located in one place or distributed across multiple network module units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0173] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for testing the multi-axis repeatability accuracy of an X-ray device, characterized in that, include: Step 1: When the detection device is in the first position, acquire a standard projection image of the test object and perform flat field correction; Step 2: When the detection device moves to a random coordinate position and returns to the first position, a random projection image of the test object is acquired; the test object is a tungsten wire tool. Step 3: Calculate the residual plot of the random projection plot relative to the standard projection plot, and perform normalization processing; Step 4: Compare the residual plot with the standard residual plot set used to provide standard offset values ​​to obtain the offset of the X and Y axes of the detection device; Step 5: Repeat steps 1 to 5 N times to obtain N offsets; Step Six: Determine the maximum value among the N offsets as the repeatability accuracy test result of the detection device; The standard residual plot set was obtained using the following method: Step A: When the detection device is in the first position, acquire a standard projection image of the test object and perform flat-field correction; Step B: Move the detection device by a preset distance along a preset direction; Step C: Acquire the offset projection map of the detection device in its current state and perform flat-field correction; Step D: Calculate the residual map of the offset projection map relative to the standard projection map; Step E: Normalize the residual map and establish a correspondence with the corresponding translation axis offset value; Step F: Repeat steps B to E until the preset conditions are met, and obtain N offset values ​​and the corresponding residual plots; Step G: Collect the offset values ​​and corresponding residual plots, and generate a standard offset value residual plot group file.

2. The method for testing the multi-axis repeatability accuracy of an X-ray device according to claim 1, characterized in that, Before performing step four, the method further includes: Flat field correction is performed on the standard projection map and the random projection map.

3. The method for testing the multi-axis repeatability accuracy of an X-ray device according to claim 1 or 2, characterized in that, The flat-field correction of the standard projection map and the random projection map includes: Acquire dark field images; After removing the test object, a bright field image was acquired; Based on the acquired bright field and dark field images, flat field correction is performed.

4. The method for testing the multi-axis repeatability accuracy of an X-ray device according to claim 1, characterized in that, The detection equipment includes: a detector and a radiation source mounted on different moving bearings; The steps for obtaining the standard projection image when the acquisition and detection device is in the first position specifically include: The detector and the radiation source are moved to a position corresponding to the first position, so that the X-ray device passes through the detection equipment to generate the standard projection image.

5. The method for testing the multi-axis repeatability accuracy of an X-ray device according to claim 1, characterized in that, The preset distance is 1 micrometer; the preset condition is that the sum of the preset distances reaches N micrometers.

6. A multi-axis repeatability accuracy testing system for an X-ray device, used to perform the testing method as described in any one of claims 1-5, characterized in that, include: A standard projection image acquisition module is used to acquire clear "grid" images that can be collected by an X-ray device through a "grid" mold; the mold is a tungsten wire mold. The flat field correction module is used to acquire a bright field image and a dark field image, correct the image gain, and eliminate noise; The residual map information analysis module is used to calculate the residual map of the projection map to be tested relative to the standard projection map, and perform normalization processing. The obtained residual map is compared with the standard X and Y axis offset residual map to obtain the offset of the X and Y axes.

7. A CT imaging testing system for performing the testing method as described in any one of claims 1-5, characterized in that, Specifically, it includes: An X-ray emitting device for emitting the X-rays includes upper X-ray and upper Y-ray bearing detectors and lower X-ray and lower Y-ray bearing ray sources. A projection image capture device, used to acquire projection images; A control device used to control the coordinate positions of the upper X and upper Y axes, as well as the lower X and lower Y axes; The device under test is used for experimental testing.

8. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method as described in any one of claims 1-5.

9. A computer program product containing program code, characterized in that, When the computer program product is run on an electronic device, it causes the electronic device to perform the method as described in any one of claims 1 to 5.

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