Image stitching method and image scanning system

Abstract

Provided in the present application are an image stitching method and an image scanning system. The image stitching method comprises the following steps: placing a calibration sample picture; according to a static scanning result of the calibration sample picture, focusing imaging modules; according to a stitching result of each scanned image of the calibration sample picture, determining supplementation and correction parameters for each scanned image, each scanned image of the calibration sample picture being obtained by dynamically scanning the calibration sample picture; using the supplementation and correction parameters to supplement and correct each scanned image of a target image, each scanned image of the target image being obtained by dynamically scanning the target image; and stitching the supplemented and corrected scanned images of the target image. The technical solution of the present application effectively simplifies and integrates each processing step of image stitching processes, thereby greatly improving image stitching efficiency and effects.

Description

Image stitching method and image scanning system Technical Field

[0001] The present application relates to the technical field of image scanning and digital image processing, and specifically provides an image stitching method and an image scanning system. Background Art

[0002] Through optical magnification imaging, magnification scanning is performed using array-type alternately arranged magnification imaging modules, which can achieve high-resolution imaging of the target image on the object surface without changing the existing CIS (Contact Image Sensor) structure. For example, the invention patent application with application number 202211180946.1 submitted by the same applicant provides a device for full-coverage magnification imaging and acquisition of the image to be detected on the object surface through the above-mentioned design.

[0003] Since the scanning areas of the various imaging modules of the above-mentioned device overlap, it is necessary to first obtain the overlap and offset of each image before stitching the scanned images. For this purpose, the same applicant proposed a method for correcting the scanned images of each imaging module in the invention patent with application number 202310265652.7. During the implementation of this method, it is necessary to first measure the calibration points on the first target, and then perform multiple steps of calculation processing in the subsequent processing process. The amount of data calculation is large, which is not conducive to the rapid calibration and stitching of image scans.

[0004] To this end, it is necessary to improve the existing calibration and stitching methods, find a method with simple implementation steps and good calibration effect, and use this method to create a highly integrated image scanning system to achieve simple and rapid magnification scanning and correct stitching of images on the object surface.

[0005] Summary of the Invention

[0006] To solve the problems existing in the above-mentioned prior art, the present application provides an image stitching method for stitching scanned images obtained by dynamic scanning of an imaging module. The method comprises the following steps:

[0007] Place the calibration sample;

[0008] Focusing the imaging module according to the static scanning results of the calibration sample;

[0009] determining correction parameters of each scanned image according to a splicing result of each scanned image of the calibration sample, wherein each scanned image of the calibration sample is obtained by dynamically scanning the calibration sample;

[0010] Correcting each scanned image of the target image using the correction parameters, wherein each scanned image of the target image is obtained by dynamically scanning the target image;

[0011] The scanned images of the corrected target image are stitched together.

[0012] Furthermore, the correction parameters of each scanned image include an overlap amount of each scanned image in a scanning direction and an offset amount in a sub-scanning direction, wherein the sub-scanning direction is perpendicular to the scanning direction.

[0013] Furthermore, the calibration sample is a two-dimensional sample, and a first mark and a second mark are set on its surface facing the imaging module; the first mark is a plurality of straight lines evenly distributed along the scanning direction and extending along the sub-scanning direction; the second mark is a straight line extending along the scanning direction.

[0014] Preferably, the line width of the straight line is 3.9 to 5 times the minimum imaging size of the imaging module.

[0015] Preferably, among the multiple straight lines of the first mark, the distance between any two adjacent straight lines is the difference between the theoretical scanning length of each scanned image along the scanning direction and the theoretical scanning overlap length of any two adjacent scanned images along the scanning direction.

[0016] Preferably, the calibration sample also includes a third mark and a fourth mark; the third mark is a straight line with an angle of 45° with the scanning direction and the sub-scanning direction; the fourth mark is a cross line, and the intersecting lines of the cross line are parallel to the scanning direction and the sub-scanning direction respectively.

[0017] Furthermore, focusing the imaging module according to the static scanning result of the calibration sample includes the following steps:

[0018] Slightly adjust the position of the calibration sample so that the first mark in the calibration sample can be fully displayed;

[0019] The distance between the imaging module and the calibration sample is adjusted until all straight lines of the first mark are clearly displayed in the scanned image obtained by the imaging module.

[0020] Furthermore, the step of determining the correction parameters of each scanned image according to the stitching result of each scanned image of the calibration sample comprises the following steps:

[0021] Fix the position of the calibration sample and use the imaging module to dynamically scan the calibration sample, wherein the dynamic scanning is to scan the calibration sample in multiple lines along the secondary scanning direction;

[0022] Stitching the scanned images of the calibration sample obtained by scanning the imaging module;

[0023] Calculating the repeated imaging spacing of each straight line in the first mark along the scanning direction from the stitching result, and determining the overlap amount of each scanned image in the scanning direction based on the repeated imaging spacing;

[0024] The segmented offsets of the straight lines in the second mark are calculated from the splicing result, and the offsets of the respective scanned images in the sub-scanning direction are determined based on the segmented offsets.

[0025] The present application also provides an image scanning system for scanning a target image and performing image stitching using the aforementioned image stitching method. The image scanning system includes:

[0026] Motion module, light source module, imaging module, display module, focusing module and data processing module;

[0027] The motion module is used to carry and enable the calibration sample and the target image to move along the secondary scanning direction;

[0028] The light source module provides linear high-brightness lighting for the imaging module;

[0029] The imaging module scans and forms images of the calibration sample and the target image;

[0030] The display module displays the scanning imaging result of the imaging module in real time;

[0031] The focusing module is used to adjust the focus position of the imaging module;

[0032] The data processing module is used to determine the correction parameters and to splice the calibration sample and each scanned image of the target image.

[0033] The image stitching method provided in the embodiments of the present application can quickly and accurately obtain the focal length of the imaging module and the correction parameters of each scanned image along the scanning direction and the sub-scanning direction by integrating calibration samples of multiple detection information, effectively simplifying and integrating the various processing steps in the image stitching process into the image scanning system, greatly improving the efficiency and effect of image stitching. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic diagram of an image scanning system according to an embodiment of the present application;

[0035] FIG2 is a schematic diagram of the appearance of an image scanning system according to an embodiment of the present application;

[0036] FIG3 is a side view of the internal structure of an imaging module in an image scanning system according to an embodiment of the present application;

[0037] FIG4 is a schematic diagram of an operation mode of a display module in an image scanning system according to an embodiment of the present application;

[0038] FIG5 is a schematic diagram showing the scanning principle of an imaging module in an image scanning system according to an embodiment of the present application;

[0039] FIG6 is a flow chart of an image stitching method according to an embodiment of the present application;

[0040] FIG7 is a top view of a calibration sample according to an embodiment of the present application;

[0041] FIG8 is a schematic diagram of imaging results of a static scan of a calibration sample according to an embodiment of the present application;

[0042] FIG9 is a stitching result of scanned images obtained by dynamically scanning a calibration sample according to an embodiment of the present application;

[0043] FIG10 is a partial enlarged schematic diagram of a portion of the first mark in FIG9 ;

[0044] FIG11 is a partial enlarged schematic diagram of a portion of the second mark in FIG9 ;

[0045] FIG12 is a result of stitching the scanned images of the calibration sample after correction according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0047] For ease of understanding, various components in the drawings are enlarged or reduced, but this practice is not intended to limit the scope of protection of this application. In addition, in the description of the embodiments of this application, if the terms "upper", "lower", "inner", "outer", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the products of the embodiments of this application are usually placed when in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting this application.

[0048] The vocabulary in this specification is used to illustrate the embodiments of the present application, but is not intended to limit the present application. It should also be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a communication between the two components. For those skilled in the art, the specific meanings of the above terms in this application can be specifically understood.

[0049] The present application is described in detail below with reference to the accompanying drawings.

[0050] FIG1 is a schematic diagram of the architecture of an image scanning system according to some embodiments, and FIG2 is a schematic three-dimensional diagram of the image scanning system in a specific embodiment.

[0051] As shown in FIG. 1 and FIG. 2 , the image scanning system includes a motion module 5 , a light source module 3 , an imaging module 2 , a display module 7 , a focusing module 1 and a data processing module 6 .

[0052] Specifically, the focusing module 1 is primarily used to adjust the focal position of the imaging module 2 so that the imaging module 2 can clearly magnify and image the image on the object plane 4. Preferably, the focusing module 1 includes a micrometer fine adjustment structure 11 with a digital display function, which is used to adjust the position of the imaging module 2 along the vertical direction in Figure 2 with an accuracy of microns. Furthermore, as shown in Figure 2, the focusing module 2 preferably also includes a guide structure 12, which can be a linear slide or other structure to limit the movement direction of the imaging module 2.

[0053] Figure 3 shows a side view of the internal structure of imaging module 2, with the direction perpendicular to the paper as the scanning direction. As shown in Figure 3, imaging module 2 comprises a frame 21, imaging lenses 23, a photoelectric conversion chip 25, and a chip substrate 26. Frame 21 is used to house the internal components. Multiple imaging lenses 23 are arranged linearly along the scanning direction and spaced apart in two rows along the sub-scanning direction (generally, the sub-scanning direction and the scanning direction are both parallel to object plane 4, with the sub-scanning direction perpendicular to the scanning direction). To achieve full-coverage scanning, the two rows of imaging lenses 23 are staggered. Furthermore, in some preferred embodiments, the magnification of imaging lenses 23 is 1.67x. Photoelectric conversion chips 25 are mounted on chip substrate 26, corresponding one-to-one with imaging lenses 23. They convert optical signals transmitted from object plane 4 through imaging lenses 23 into analog signals for output. The output signals are ultimately connected via a large socket 201 to socket 204 on substrate 29 of data processing unit 6, enabling signal conversion and transmission.

[0054] For example, if the resolution of the photoelectric conversion chip 25 is 1200 DPI, the minimum pixel at 1200 DPI is 25.4 / 1200 ≈ 21 μm. This means the minimum resolution of the image plane is 21 μm, while the magnification of the imaging lens 23 is 1.67x. By calculating the magnification, we can see that the minimum resolution of the object plane 4 is 21 / 1.67 ≈ 12.5 μm, meaning the imaging resolution of the image on object plane 4 is 2000 DPI. This allows a low-resolution chip to scan a high-resolution object surface.

[0055] Accordingly, the imaging module 2 is used to perform a full-coverage scan of the image on the object surface along the scanning direction, and each scan produces a single line of scan results. By varying the position of the imaging module 2 relative to the object surface 4 along the secondary scanning direction and continuously performing multiple line scans, a two-dimensional scanned image can be obtained. The specific structure and operating principle of the imaging module 2 have been described in detail in multiple patents previously filed by the applicant, such as Chinese invention patent application number 202211180946.1, and will not be further elaborated here.

[0056] In order to change the relative position of the imaging module 2 and the object plane 4 along the sub-scanning direction, the image scanning system is also provided with a motion module 5. The upper surface of the motion module 5 is a platform structure. Obviously, when the imaging module 2 can be clearly focused on the upper surface of the platform structure, the upper surface of the platform structure is the object plane 4 of the imaging module.

[0057] Furthermore, the upper surface of the motion module 5 can carry the calibration sample and target image described later, and a groove structure can be set thereon for positioning the calibration sample to ensure the consistency of the placement of the calibration sample and the target image; the interior of the motion module 5 is equipped with a motor, a slide rail and other structures, and the upper computer software sends a pulse drive signal to the motor, and the motor will drive the platform and the calibration sample or target image placed thereon to move along the sub-scanning direction.

[0058] Furthermore, the light source module 3 provides a linear lighting source for the object surface 4. The distance between the light source module 3 and the object surface 4 can be achieved through a height adjustment structure 31. The height adjustment structure 31 has corresponding positioning holes, and the spacing between the positioning holes can be moved according to a preset distance spacing (for example, 5 mm); the adjustment of the light source angle can be achieved through an angle adjustment structure 32. The angle adjustment structure 32 has a corresponding gear structure, which can achieve angle adjustment according to a preset angle spacing (for example, 2°).

[0059] The data processing module 6 includes a substrate 29, which also houses circuits such as an FPGA chip 202 and a serial port 203. The FPGA chip reads image signals and, through internal register settings, controls the timing cycle to achieve synchronous control of the light source signal emitted by the light source module 3. The FPGA chip also performs image processing, including processing overlapping portions of images along the scanning direction and deviations along the sub-scanning direction, thereby enabling the splicing and synthesis of multiple images.

[0060] Figure 4 shows a schematic diagram of the operating modes of display module 7. After the data processing module processes the image, the data is sent to the display module 7 via the serial port of the baseboard for display. The display module can be installed on a PC, and the image is displayed using the PC's host computer software. In the embodiment shown in Figure 4, the display module 7 has operating modes such as Snap, Grab, and Demo. Snap is a single round-trip scan, Grab is a static photo, and Demo is a continuous round-trip motion.

[0061] FIG5 is a schematic diagram illustrating the principle of imaging module 2 scanning object plane 4 in a specific embodiment. In this embodiment, imaging module 2 includes a total of six imaging lenses and corresponding photoelectric conversion chips, which are arranged in two rows along the secondary scanning direction. Each row is evenly spaced along the scanning direction, and the two rows are offset from each other to achieve full coverage scanning of object plane 4. For ease of illustration, the horizontal direction in the figure is the scanning direction, and the vertical direction is the secondary scanning direction. It should be noted that in actual embodiments, the secondary scanning direction in the figure is perpendicular to the paper.

[0062] The effective scanning areas of each image in Figure 5 are 501 to 506 respectively. When the object distance is 25 mm, the theoretical scanning length of each effective scanning area is 11 mm. Adjacent effective scanning areas theoretically have an overlap of length △X = 0.5 mm along the scanning direction and are aligned with each other in the sub-scanning direction (△Y = 0).

[0063] That is, in theory, the difference between the theoretical scanning length of each scanned image along the scanning direction and the theoretical scanning overlapping length of any two adjacent scanned images along the scanning direction is 11mm-0.5mm=10.5mm, and there is no deviation in the sub-scanning direction of each scanned image. However, due to various reasons such as lens installation, processing accuracy, and tilt, the actual image will have deviations, that is, there is uncertainty in the number of overlapping points in the scanning direction and the number of offset points in the sub-scanning direction.

[0064] To this end, in some embodiments of the present application, an image stitching method for the image scanning system is also provided to ensure that the image scanning system can quickly, conveniently and accurately stitch multiple scanned images.

[0065] FIG6 is a flow chart of the image stitching method, which is described in detail below. As shown in FIG6 , the image stitching method includes the following steps:

[0066] Step S100: placing a calibration sample.

[0067] FIG7 shows a schematic diagram of a calibration sample in a specific embodiment. As shown in FIG7 , the calibration sample is a two-dimensional sample, and a first mark and a second mark are provided on the surface of the calibration sample facing the imaging module.

[0068] Specifically, the first mark is a plurality of straight lines A1, A2, A3, A4, and A5 distributed at equal intervals along the scanning direction, and the straight lines A1 to A5 extend along the sub-scanning direction. The second mark is a straight line extending along the scanning direction.

[0069] Furthermore, the width of each straight line should meet the needs of focusing the imaging module. Taking the object plane imaging resolution of 2000DPI as an example, the pixel size of each clear image is 12.7um. Therefore, the minimum value of the line width of each straight line can be set to 50um, 50um / 12.7um≈3.94, that is, a straight line of this line width can form approximately 4 pixels on the scanned image on the basis of accurate focus (further, the line width can be appropriately increased so that it can form a clear display of about 5 pixels).

[0070] Furthermore, as analyzed above, the spacing between any two adjacent lines among lines A1 to A5, such as A1 and A2, and A2 and A3, is the difference between the theoretical scanning length of each scanned image along the scanning direction and the theoretical scanning overlap length of any two adjacent scanned images along the scanning direction. That is, if the theoretical effective scanning length of each photoelectric conversion chip in the imaging module is 11 mm, and the theoretical scanning overlap length of adjacent photoelectric conversion chips along the scanning direction is 0.5 mm, the spacing between A1 and A2, A2 and A3, and so on, is 10.5 mm. This arrangement ensures that the same first marker line is captured in the overlapping region of the image scanned by any two adjacent light conversion chips.

[0071] Furthermore, as shown in Figure 7, in some preferred embodiments, the calibration sample also includes a third mark and a fourth mark. The third mark is a straight line with a 45° angle with both the scanning direction and the sub-scanning direction; the fourth mark is a crosshair, the intersection of which is parallel to the scanning direction and the sub-scanning direction, respectively. The third and fourth marks can be used to further confirm the correction results of the stitched image in the scanning and sub-scanning directions.

[0072] Step S200 , focusing the imaging module according to the static scanning result of the calibration sample.

[0073] In some preferred embodiments, step S200 further includes the following steps:

[0074] Slightly adjust the position of the calibration sample so that the first mark in the calibration sample can be fully displayed;

[0075] The distance between the imaging module and the calibration sample is adjusted until all straight lines of the first mark are clearly displayed in the scanned image obtained by the imaging module.

[0076] Specifically, you can click Grab in the display module 7 as shown in Figure 4 to perform a static scan. At this time, the motion module 5 enables multiple straight lines of the first mark in the calibration sample to be fully displayed, where each straight line A1-A5 is exactly in the overlapping area of ​​the two images, so in the spliced ​​image, each of the above straight lines is displayed as two vertical lines.

[0077] At this time, the fine-tuning structure 11 is rotated to confirm the focus position. Since the line width of each straight line A1-A5 along the scanning direction is 50um, 50um / 12.7um ≈ 4 points, the image shows 4-5 points clearly, which means that the focus position adjustment is completed. At this time, the image shown in Figure 8 will be displayed on the display module 7.

[0078] Step S300 : determining correction parameters of each scanned image according to a splicing result of each scanned image of the calibration sample, wherein each scanned image of the calibration sample is obtained by dynamically scanning the calibration sample.

[0079] In some preferred embodiments, step S300 further includes the following steps:

[0080] The first step is to fix the calibration sample's position and use the imaging module to dynamically scan it. Dynamic scanning involves scanning multiple lines of the calibration sample along the secondary scanning direction. Specifically, you can fix the sample's position and click Snap. The platform then moves the calibration sample, and the imaging module 2 scans it simultaneously, obtaining scanned images output by each photoelectric conversion chip.

[0081] The second step is to stitch together the scanned images of the calibration sample obtained by the imaging module. Figure 9 shows the result of directly stitching together the scanned images. Figures 10 and 11 respectively show partial enlarged schematic diagrams of a portion of the first mark and a portion of the second mark in Figure 9. As shown in Figures 9 and 11, the images directly stitched together from the scanned images of the calibration sample have overlap along the scanning direction and offset along the sub-scanning direction.

[0082] The third step is to calculate the repetitive imaging spacing along the scanning direction for each line in the first mark from the stitching result. Based on this repetitive imaging spacing, the overlap of each scanned image in the scanning direction is determined. Specifically, the number of points along the scanning direction that differ between the two vertical lines displayed at the intersection of two adjacent scanned images can be directly calculated. This number of points is the number of points of overlap of the adjacent scanned images in the scanning direction.

[0083] The fourth step is to calculate the segmented offsets of the lines in the second marker from the stitching result, and determine the offset of each scanned image in the sub-scanning direction based on these segmented offsets. Specifically, because the second marker is offset in the sub-scanning direction in each scanned image, the offset of each scanned image in the sub-scanning direction can also be determined by the number of offset points between adjacent scanned images.

[0084] Table 1 below shows the correction parameters determined through the above steps in a specific embodiment.

[0085] Table 1 Correction parameters (unit: pixel count)

[0086] The correction parameters can be stored in the storage space of the data processing module for subsequent correction of the scanning result of the target image.

[0087] Step S400, correcting each scanned image of the target image using the correction parameters, wherein each scanned image of the target image is obtained by dynamically scanning the target image;

[0088] Step S500 , stitching the scanned images of the corrected target image.

[0089] After obtaining the above correction parameters, the actual target image can be scanned, corrected and image stitched. The dynamic scanning steps for the target image are consistent with the dynamic scanning steps for the calibration sample. After obtaining each scanned image of the target image, the data processing module 6 changes the parameters in the register according to the correction parameters, so as to achieve the removal of overlapping points in the scanning direction and the correction of the offset in the sub-scanning direction. After processing the above data, a complete image is formed, and the processed image data is transmitted to the PC through the serial port for image qualification judgment. Figure 12 shows the image stitching result after correction using the calibration sample as the target image. As shown in Figure 12, the image stitching method provided by this application can conveniently and accurately stitch scanned images.

[0090] The above is a detailed introduction to the specific implementation methods of the present application. For those skilled in the art, several improvements and modifications can be made to the present application without departing from the principles of the present application. These improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. An image stitching method for stitching scanned images obtained by dynamic scanning of an imaging module, comprising the following steps: Place the calibration sample; Focusing the imaging module according to the static scanning result of the calibration sample; Determining correction parameters of each scanned image according to a splicing result of each scanned image of the calibration sample, wherein each scanned image of the calibration sample is obtained by dynamically scanning the calibration sample; Correcting each scanned image of the target image using the correction parameters, wherein each scanned image of the target image is obtained by dynamically scanning the target image; The scanned images of the corrected target image are stitched together.

2. The image stitching method according to claim 1, characterized in that: The correction parameters of each scanned image include an overlap amount of each scanned image in a scanning direction and an offset amount in a secondary scanning direction, wherein the secondary scanning direction is perpendicular to the scanning direction.

3. The image stitching method according to claim 2, characterized in that: The calibration sample is a two-dimensional sample, and a first mark and a second mark are arranged on its surface facing the imaging module; The first marks are a plurality of straight lines that are equally spaced along the scanning direction and extend along the sub-scanning direction; The second mark is a straight line extending along the scanning direction.

4. The image stitching method according to claim 3, characterized in that: The line width of the straight line is 3.9 to 5 times the minimum imaging size of the imaging module.

5. The image stitching method according to claim 3, characterized in that: Among the multiple straight lines of the first mark, the distance between any two adjacent straight lines is the difference between the theoretical scanning length of each scanned image along the scanning direction and the theoretical scanning overlap length of any two adjacent scanned images along the scanning direction.

6. The image stitching method according to claim 3, characterized in that: The calibration sample also includes a third mark and a fourth mark; The third mark is a straight line having an angle of 45° with the scanning direction and the sub-scanning direction; The fourth mark is a cross line, and the intersecting lines of the cross line are parallel to the scanning direction and the sub-scanning direction respectively.

7. The image stitching method according to claim 4, characterized in that: The step of focusing the imaging module according to the static scanning result of the calibration sample comprises the following steps: Slightly adjust the position of the calibration sample so that the first mark in the calibration sample can be fully displayed; The distance between the imaging module and the calibration sample is adjusted until all straight lines of the first mark can be clearly displayed in the scanned image obtained by the imaging module.

8. The image stitching method according to claim 5, characterized in that: Determining the correction parameters of each scanned image according to the splicing results of each scanned image of the calibration sample includes the following steps: The position of the calibration sample is fixed, and the calibration sample is dynamically scanned using an imaging module, wherein the dynamic scanning is to perform multiple-line scanning on the calibration sample along a secondary scanning direction; splicing scanned images of the calibration sample obtained by scanning the imaging module; Calculating the repeated imaging spacing of each straight line in the first mark along the scanning direction from the stitching result, and determining the overlap amount of each scanned image in the scanning direction based on the repeated imaging spacing; The segmented offset of the straight line in the second mark is calculated from the splicing result, and the offset of each scanned image in the sub-scanning direction is determined based on the segmented offset.

9. An image scanning system for scanning a target image and performing image stitching using the image stitching method according to claim 1, characterized in that: It includes a motion module, a light source module, an imaging module, a display module, a focusing module and a data processing module; The motion module is used to carry and enable the calibration sample and the target image to move along the secondary scanning direction; The light source module provides linear high-brightness illumination for the imaging module; The imaging module scans and images the calibration sample and the target image; The display module displays the scanning imaging result of the imaging module in real time; The focusing module is used to adjust the focal position of the imaging module; The data processing module is used to determine the correction parameters and to splice the calibration sample and each scanned image of the target image.

Images