A projection imaging method, apparatus, device, and storage medium

Abstract

The application discloses a projection imaging method, device, equipment and storage medium, and the method comprises the following steps: acquiring a first projection image formed by a light source irradiating a square cross-section of a sample to be projected; performing horizontal translation, vertical translation, horizontal translation and vertical translation on the first projection image respectively according to a preset displacement to obtain a second projection image, a third projection image and a fourth projection image; then constructing corresponding image data matrices; subtracting a first sum matrix of the first image data matrix and the fourth image data matrix from a second sum matrix of the second image data matrix and the third image data matrix to obtain a fifth image data matrix; and inversely calculating the fifth image data matrix to obtain a fifth projection image, which is taken as a projection image of the sample to be projected. Through the application, the resolution of the projection image can be improved without changing the size of the light source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection imaging, in particular to a projection imaging method, device, equipment and storage medium. BACKGROUND

[0002] In the use of X-ray projection imaging technology, the resolution of the projection image is roughly equal to the size of the X-ray light source. However, if the size of the X-ray light source is too small, the intensity of the X-ray light source will be weak, and the projection imaging cannot be performed within a limited time. Therefore, the resolution of the projection image is usually only in the sub-millimeter range, which cannot meet the requirement of the micron-level resolution of biological cells. Therefore, a new projection imaging method is needed to improve the resolution of the projection image without changing the size of the X-ray light source. SUMMARY

[0003] The present application provides a projection imaging method, device, equipment and storage medium to solve the technical problem of low resolution of the projection image in the existing projection imaging method.

[0004] In order to solve the above technical problem, the present application provides a projection imaging method, comprising:

[0005] Obtaining a first projection image formed by a square cross-section light source irradiation of a sample to be projected; wherein the resolution of the first projection image is similar to the size of the square cross-section light source;

[0006] Translating the first projection image horizontally by a preset displacement to obtain a second projection image;

[0007] Translating the first projection image vertically by a preset displacement to obtain a third projection image;

[0008] Translating the first projection image horizontally and vertically by a preset displacement to obtain a fourth projection image; wherein the preset displacement is smaller than the size of the square cross-section light source;

[0009] According to the first projection image, the second projection image, the third projection image and the fourth projection image, a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix are constructed respectively;

[0010] Adding the first image data matrix and the fourth image data matrix to obtain a first sum matrix; adding the second image data matrix and the third image data matrix to obtain a second sum matrix; subtracting the second sum matrix from the first sum matrix to obtain a fifth image data matrix;

[0011] According to the fifth image data matrix, a fifth projection image is obtained by inversion, and the fifth projection image is taken as the projection image of the sample to be projected.

[0012] As a preferred solution, the first image data matrix, the second image data matrix, the third image data matrix and the fourth image data matrix are respectively constructed according to the first projection image, the second projection image, the third projection image and the fourth projection image, and the method comprises the following steps:

[0013] A coordinate system is established with a vertex of the upper left corner of the first projection image as a coordinate origin, a horizontal direction as an x-axis and a vertical direction as a y-axis, and the first image data matrix is constructed according to the coordinates of each pixel point of the first projection image in the coordinate system.

[0014] The second image data matrix is constructed according to the coordinates of each pixel point of the second projection image in the coordinate system.

[0015] The third image data matrix is constructed according to the coordinates of each pixel point of the third projection image in the coordinate system.

[0016] As a preferred solution, the fifth projection image is obtained by inversion according to the fifth image data matrix, and the method comprises the following steps:

[0017] According to the fifth image data matrix, the positive value contribution of the fifth image data matrix is extracted, and then the fifth projection image is obtained by inversion according to the positive value contribution.

[0018] As a preferred solution, the fifth projection image contains two projections of the sample to be projected, and the two projections respectively fall on two ends of a same diagonal line of the fifth projection image.

[0019] On the basis of the above-mentioned embodiments, another embodiment of the present application provides a projection imaging device, which comprises a first projection image acquisition module, a second projection image acquisition module, a third projection image acquisition module, a fourth projection image acquisition module, an image data matrix construction module, a fifth image data matrix calculation module and a fifth projection image inversion module.

[0020] The first projection image acquisition module is used for acquiring a first projection image formed by a light source after irradiation of a square cross section of a sample to be projected, wherein the resolution of the first projection image is similar to the size of the light source of the square cross section.

[0021] The second projection image acquisition module is used for horizontally translating the first projection image by a preset displacement to obtain a second projection image.

[0022] The third projection image acquisition module is configured to vertically translate the first projection image by a preset displacement to obtain a third projection image.

[0023] The fourth projection image acquisition module is configured to horizontally and vertically translate the first projection image by a preset displacement to obtain a fourth projection image, wherein the preset displacement is smaller than the size of the light source with the square cross section.

[0024] The image data matrix construction module is configured to construct a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix according to the first projection image, the second projection image, the third projection image and the fourth projection image, respectively.

[0025] The fifth image data matrix calculation module is configured to add the first image data matrix and the fourth image data matrix to obtain a first sum matrix, add the second image data matrix and the third image data matrix to obtain a second sum matrix, and subtract the second sum matrix from the first sum matrix to obtain a fifth image data matrix.

[0026] The fifth projection image inversion module is configured to perform inversion according to the fifth image data matrix to obtain a fifth projection image, and use the fifth projection image as the projection image of the sample to be projected.

[0027] As a preferred solution, the fifth projection image inversion module further includes a positive value contribution extraction unit.

[0028] The positive value contribution extraction unit is configured to extract the positive value contribution of the fifth image data matrix according to the fifth image data matrix.

[0029] On the basis of the above-mentioned embodiments, a further embodiment of the application provides a projection imaging device, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the projection imaging method of the above-mentioned embodiments of the application when executing the computer program.

[0030] On the basis of the above-mentioned embodiments, a further embodiment of the application provides a storage medium, which comprises a stored computer program, wherein the computer program controls a device in which the computer readable storage medium is located to execute the projection imaging method of the above-mentioned embodiments of the application when the computer program is running.

[0031] Compared with the prior art, the embodiments of the application have the following beneficial effects:

[0032] In the prior art, the resolution of the projection image obtained after the sample to be projected is projected and imaged by a circular light source is similar to the size of the circular light source. Due to the limitation of the size of the light source, the resolution of the projection image is low. In the embodiment of the present application, a light source with a square cross section is adopted. First, a first projection image with a low resolution is obtained by projection and imaging, wherein the resolution of the first projection image, i.e. the minimum spot size, is similar to the size of the light source with the square cross section. Then, a "square shift difference" of the first projection image, i.e. a fifth image data matrix, is constructed. The fifth projection image can be obtained by inversion according to the fifth image data matrix, wherein the minimum spot size of the fifth projection image is in the same order of magnitude as the preset displacement amount. Since the displacement amount is smaller than the size of the light source with the square cross section, the minimum spot size of the fifth projection image is also smaller than the minimum spot of the first projection image, i.e. the resolution of the fifth projection image is higher than the resolution of the first projection image.

[0033] By setting the displacement amount < light source size, the minimum spot size of the fifth projection image < the minimum spot size of the first projection image, i.e. the resolution of the fifth projection image > the resolution of the first projection image, can be realized, so as to obtain a projection image with higher resolution. Through the embodiment of the present application, a light source with a square cross section can be adopted to obtain a projection image with higher resolution by inversion of the projection image without changing the size of the light source, so as to improve the resolution of the projection image. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a flowchart of a projection imaging method provided by an embodiment of the present application;

[0035] Figure 2 is a projection imaging demonstration diagram of an x-ray with a square cross section;

[0036] Figure 3 is a projection imaging geometric diagram of an x-ray with a square cross section;

[0037] Figure 4 is an image superposition diagram of a square projection image;

[0038] Figure 5 is a construction principle diagram of a square shift difference of a projection image;

[0039] Figure 6 is a schematic diagram of a projection sample, a first projection image and a fifth projection image;

[0040] Figure 7 is a Matlab instruction for constructing a square shift difference; TM

[0041] Figure 8 is a schematic diagram of a projection image of a circular light source; ​

[0042] Figure 9 is a structural schematic diagram of an experimental device of a projection demonstration;

[0043] Figure 10 is a microscope image of a projection sample made of a metal foil;

[0044] Figure 11 is a schematic diagram of a projection image generated by a projection demonstration;

[0045] Figure 12 is a projection sample image taken by a CMOS sensor of a digital camera;

[0046] Figure 13 is a schematic diagram of a fifth projection image obtained by inversion in a projection demonstration;

[0047] Figure 14 is a structural schematic diagram of a projection imaging device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0049] Embodiment one

[0050] Please refer to Figure 1 is a flow schematic diagram of a projection imaging method provided by an embodiment of the present application, including the following specific steps:

[0051] S1, obtaining a first projection image formed by a light source of a square cross section irradiating a sample to be projected; wherein the resolution of the first projection image is similar to the size of the light source of the square cross section;

[0052] Please refer to Figure 2 is a projection imaging demonstration diagram of an x-ray of a square cross section. A short-wavelength x-ray light source of a square cross section is used to irradiate and project a sample to be projected. Due to the ballistic nature and sub-micron coherence length of the short-wavelength x-ray, the light source will generate many projection beams passing through the object, and then all these beams are superimposed on each other to form a blurred projection image on the projection detector. The projection image is the first projection image, and the minimum spot size, i.e. the resolution of the first projection image, is similar to the size of the x-ray of the square cross section. Due to the limitation of the size of the light source, the minimum spot size of the first projection image is large, and the resolution is low.

[0053] Please refer toFigure 3 For the projection imaging geometry of the x-ray with square cross section, the following takes a pinhole sample as the sample to be projected, and the pinhole sample is irradiated by the x-ray with square cross section.

[0054] If a matrix g corresponding to the light source with square cross section and a matrix f corresponding to the pinhole sample are constructed respectively, a matrix p corresponding to the first projection image is obtained by matrix convolution of g and f, and here the (x, y) ratio of f and p can be adjusted to simplify the derivation. For g, the pinhole sample is considered, where f is a delta function, so p is the same as g, which is square rather than pinhole, which shows that the first projection image formed by the pinhole sample irradiated by the light source with square cross section is a square consistent with the cross section of the light source rather than a pinhole.

[0055] S2, the first projection image is horizontally translated by a preset displacement amount to obtain a second projection image, the first projection image is vertically translated by a preset displacement amount to obtain a third projection image, and the first projection image is horizontally translated and vertically translated by a preset displacement amount to obtain a fourth projection image, wherein the preset displacement amount is smaller than the size of the light source with square cross section;

[0056] After the sample to be projected is irradiated by the light source with square cross section, the first projection image formed has low resolution, and at this time, the multiple pixel points contained in the smallest light spot in the first projection image can be analyzed by constructing a "square shift difference" to greatly reduce the size of the smallest light spot of the projection image and improve the resolution of the projection image. Before constructing the "square shift difference", the first projection image is horizontally translated by a preset displacement amount d to obtain a horizontal translation image, i.e., a second projection image, the first projection image is vertically translated to obtain a vertical translation image, i.e., a third projection image, and the first projection image is horizontally translated and vertically translated to obtain two directionally translated images, i.e., a fourth projection image.

[0057] S3, a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix corresponding to the first projection image, the second projection image, the third projection image and the fourth projection image are constructed respectively.

[0058] Preferably, the constructing the first image data matrix, the second image data matrix, the third image data matrix and the fourth image data matrix respectively according to the first projection image, the second projection image, the third projection image and the fourth projection image comprises: establishing a coordinate system with the top left corner of the first projection image as the coordinate origin, the horizontal direction as the x-axis and the vertical direction as the y-axis, and constructing the first image data matrix according to the coordinates of each pixel point of the first projection image in the coordinate system; constructing the second image data matrix according to the coordinates of each pixel point of the second projection image in the coordinate system; and constructing the third image data matrix according to the coordinates of each pixel point of the third projection image in the coordinate system.

[0059] In order to keep the consistency of the constructed data matrices, a coordinate system is established with the top left corner of the first projection image as the coordinate origin, the horizontal direction as the x-axis and the vertical direction as the y-axis, and the first image data matrix p(x, y), the second image data matrix p(x+d, y), the third image data matrix p(x, y+d) and the fourth image data matrix p(x+d, y+d) are constructed according to the positions of each pixel point of the projection images in the coordinate system, wherein d is the displacement along the x and y axes.

[0060] S4, adding the first image data matrix and the fourth image data matrix to obtain a first sum matrix; adding the second image data matrix and the third image data matrix to obtain a second sum matrix; subtracting the second sum matrix from the first sum matrix to obtain a fifth image data matrix;

[0061] According to the image data matrices, a "square difference differential" is constructed: p(x, y)-p(x, y+d)+p(x+d, y+d)-p(x+d, y), that is, the original square image is subtracted by the images moved in the horizontal direction and the vertical direction respectively, and then the images moved in the two directions are added. Please refer to Figure 4 , which is a schematic diagram of image superposition of square projection images. All places except the corners of the four square images cancel each other out, and they will be discarded when rewriting the image. After cancellation, the four corners are left, the top left corner and the bottom right corner are positive points, and the top right corner and the bottom left corner are negative points, which are marked by positive red points and negative blue points respectively, and the displacement can be adjusted by d.

[0062] S5, inverting the fifth image data matrix to obtain a fifth projection image, and taking the fifth projection image as the projection image of the sample to be projected.

[0063] Preferably, the inverting the fifth image data matrix to obtain the fifth projection image comprises: extracting positive value contribution of the fifth image data matrix according to the fifth image data matrix, and then inverting the positive value contribution to obtain the fifth projection image.

[0064] Preferably, the fifth projection image contains two projections of the sample to be projected, and the two projections respectively fall on two ends of a same diagonal line of the fifth projection image.

[0065] Please refer to Figure 5 For the construction principle of the "square shift difference", for a pinhole sample f and a square light source g with size D, the generated square image p, i.e. the first projection image, is in the same order of magnitude as D. Since this square image p is the smallest light spot that the detector can obtain, the resolution of this image is roughly equal to the size of the light source. Therefore, the minimum detector pixel size is in the same order of magnitude as D. If the detector pixel size is << D, it will be wasted. However, after using the "square shift difference" described above, the resolution of the image will be greatly improved to the shift amount d, and d << D = the size of the light source. At this time, if a more delicate detector is used, hundreds of new pixels can be resolved from an initially blurred pixel.

[0066] After constructing the "square shift difference" of the first projection image, i.e. the fifth image data matrix, we have deciphered the point image of the pinhole sample from the blurred square image, since the digital image only takes positive value contribution. Inverting according to the fifth image data matrix can obtain the fifth projection image, wherein the minimum light spot size of the fifth projection image is in the same order of magnitude as the shift amount d. Because the shift amount is smaller than the size of the square cross-section light source, the minimum light spot size of the fifth projection image is greatly reduced compared to the minimum light spot size of the first projection image, i.e. the resolution of the fifth projection image is improved. By adjusting the shift amount << the size of the light source, the minimum light spot size of the fifth projection image << the minimum light spot size of the first projection image can be realized, i.e. the resolution of the fifth projection image >> the resolution of the first projection image, to obtain a higher resolution projection image.

[0067] In general, any sample can be considered as the superposition of many pinholes. Therefore, the same strategy can be used to decipher a general image to obtain a finer resolution determined by the shift d than the original D size of the light source.

[0068] For the expansion from the pinhole f to the general image, please refer to Figure 6(a), is a schematic diagram of the projection sample, "K" and inverted "F" are used as the projection sample, with 0, 0.5 and 1.0 intensity, which is convolved by a 200x200 square to simulate square light source projection imaging. Please refer to 6(b), which is a schematic diagram of the first projection image, the first projection image generated is blurred, and the smallest feature is similar to a square block caused by the square light source. After constructing the first image data matrix according to the first projection image, the "square shift difference" of the first projection image p is constructed to obtain the recovered letter twin image, as shown in Figure 6 (c), which is a schematic diagram of the fifth projection image. Please refer to Figure 7 , which is a Matlab TM command for constructing the square shift difference, which is achieved by calculating the difference between the sum of two diagonals of a square element, in Matlab TM , a single line command is used, and after moving horizontally or vertically on d, the same image data matrix is added and subtracted. The generated twin image is divided by the diagonal of the original square, which is sufficient to distinguish the original blurred image. If you look closely, you can find that the resolution d of the obtained image is related to (source size D) / (signal-to-noise ratio, SNR), because the signal decreases from the center of D.

[0069] However, this scheme is not suitable for the common circular light source, from Figure 8 (a), the first projection image obtained by illuminating the projection sample shown in (a) by a circular light source, and Figure 8 (b), the fifth projection image obtained after constructing the "square shift difference" shown in (b) can be seen, the final inversion result is only a group of curves, not the image of the projection sample. As shown in Figure 8 (c), this can be understood by imagining a "pinhole sample", in which the circular light source forms a ring-shaped bright edge after subtraction, resulting in a non-zero contribution along the circle, while the square light source makes zero contribution from the edge except the corner part.

[0070] The technical scheme of the present application will be further described below with a specific embodiment:

[0071] Since commercial X-ray tubes are not easy to operate, and micron pixel detectors are not yet available for X-rays, visible light from a common LED lamp and a CMOS of a digital camera are used for experimental demonstration; please refer to Figure 9 , which is a structural schematic diagram of the experimental device for projection demonstration, including:

[0072] (1) The visible light of the common LED lamp can form a square cross-section light source by passing through the square aperture formed by arranging two vertical thin metal strip slits;

[0073] (2) The CMOS image sensor of the digital camera without lens is used as a projection detector;

[0074] (3) Projection sample: pinhole punctured metal. The experimental setup uses a non-point source centered at 550 nm wavelength, a square aperture consisting of two perpendicular slits spaced 1 mm apart by a thin metal strip, sampling by a pinhole punched metal foil, and a 3x5 mm2image sensor from a digital camera. The distance from the square aperture to the detector is about 50 mm, and the projection sample is placed in between.

[0075] Reference is made to Figure 10 (a) a microscope image of a projection sample made of a metal foil, Figure 10 (a) has one pinhole; Figure 10 (b) has three pinholes, Figure 10 (c) is the letter "C" with a scale bar of 300 microns. Since the intensity of a common non-point source can not be uniform over a square aperture, to confirm that the "square shift difference" inversion is valid, the fifth image matrix is recalculated by adding a Gaussian attenuation factor exp(-R2 / R02) on top of the square, where R is the radius from the center and Ro is set to be about 70% of the half-width of the source. As Figure 11 (a) shows a schematic of the first projection image, and its inversion is shown in Figure 11 (b), which is very similar to the inversion result of the letter projection sample above, since it varies more slowly compared to the letter.

[0076] A single photo from the digital camera generates a JPG image, as Figure 12 shows a projection sample image taken by the CMOS sensor of the digital camera, Figure 12 (a) the light source produces a square spot through a single pinhole, where the minimum spot size (resolution) in the picture is determined by the shape and size of the light source, i.e., about 1x1 mm2square, defined mainly by the double slit of the light source, and can be adjusted by the projection sample-detector distance. After inversion, we get the original image, the horizontal shift image, the vertical shift image, and the "square shift difference" in both directions, as Figure 13 (a) shows, where the minimum spot size is greatly reduced, or in other words, the resolution is greatly improved. For example Figure 12 (a) the "square" of 1 mm in size produces a pair of diagonal bright spots after the "square aperture difference", corresponding to Figure 4 the two red dots in , which are about an order of magnitude smaller in size compared to the original square. Therefore, nearly a hundred pixels hidden in the original square spot are resolved. If a smaller offset d is used, the number of pixels can be increased, in which case more pixels can be resolved from an original square spot of size D.

[0077] When there are more pinholes in the sample, as Figure 10 (b) shows, the same analysis can be applied, where the three pinholes inFigure 12 Three overlapping square spots are produced in (b). Again, the resolution is limited by the millimeter-sized light source, however, the spot size is greatly reduced after the "square shift difference" inversion. As mentioned above, in Figure 12 (b), the resolution is determined by the square of the LED lamp size, at this time 3 pinholes are blurred into three overlapping squares, if we use a circular cross-section light source, then three circular points. At this time, it is a waste to use a fine pixel detector. However, when we invert the square from the fine pixel detector by "square aperture difference", three well-separated pinholes are resolved, so that in Figure 13 (b), a more fine resolution image is produced.

[0078] The same method can be extended to more complex samples, such as Figure 10 the letter "C" in (c), but the offset d (that is, the resolution of the inverted image) depends on the source size (D) / (signal-to-noise ratio). Although the accuracy of the square hole is limited by the cutting tool, which may cause the recovered pinhole to be deformed, the main features and sample letter "C" are still clearly visible, as shown in Figure 13 (c).

[0079] Compared with point source projection imaging, the power of square cross-section can become too weak and be overwhelmed by noise, while here the signal has been greatly enhanced, so the square shift difference of the limited size source can easily survive; on the other hand, although this can be classified as a kind of coded aperture, there is a fundamental difference here: the coded aperture mainly discusses the patterned grid covering the entire aperture, such as the Fresnel zone plate, while the method here is about changing the boundary / shape. Through the above method, we have found a solution to the resolution limitation problem caused by the size of the light source, which can reveal hundreds of pixels hidden in the blurred spot due to the limited size of the light source. Unlike the traditional circular beam, the square cross-section beam proves to be a simple and effective solution, and this strategy can be extended to micron-scale light sources to achieve nanoscale resolution of biological samples, as long as a shorter wavelength is used to maintain the ballistic geometry to ignore diffraction. Since the hard X-ray wavelength is about 1 / 5000 of the visible light wavelength, a 0.1 millimeter pinhole sample is equivalent to a 20 nanometer size in the case of X-ray. Therefore, if the corresponding X-ray source and detector can be realized, the experimental demonstration here shows the potential of nanoscale resolution, and simple implementation is expected to bring comprehensive progress.

[0080] As can be seen from the above, the present application provides a projection imaging method, which can use a square cross-section light source without changing the size of the light source, and the projection image is inverted to obtain a higher resolution projection image, thereby improving the resolution of the projection image.

[0081] Example two

[0082] Please refer to Figure 14 A structure schematic diagram of a projection imaging device provided by the embodiment of the present application, the device comprising: a first projection image acquisition module, a second projection image acquisition module, a third projection image acquisition module, a fourth projection image acquisition module, an image data matrix construction module, a fifth image data matrix calculation module and a fifth projection image inversion module;

[0083] The first projection image acquisition module is configured to acquire a first projection image formed by a light source irradiating a square cross-section of a sample to be projected; wherein the resolution of the first projection image is similar to the size of the light source of the square cross-section.

[0084] The second projection image acquisition module is configured to horizontally translate the first projection image by a preset displacement to obtain a second projection image.

[0085] The third projection image acquisition module is configured to vertically translate the first projection image by a preset displacement to obtain a third projection image.

[0086] The fourth projection image acquisition module is configured to horizontally and vertically translate the first projection image by a preset displacement to obtain a fourth projection image; wherein the preset displacement is smaller than the size of the light source of the square cross-section.

[0087] The image data matrix construction module is configured to construct a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix respectively according to the first projection image, the second projection image, the third projection image and the fourth projection image.

[0088] The fifth image data matrix calculation module is configured to add the first image data matrix and the fourth image data matrix to obtain a first sum matrix; add the second image data matrix and the third image data matrix to obtain a second sum matrix; subtract the second sum matrix from the first sum matrix to obtain a fifth image data matrix.

[0089] The fifth projection image inversion module is configured to obtain a fifth projection image by inversion according to the fifth image data matrix, and take the fifth projection image as the projection image of the sample to be projected.

[0090] Preferably, the fifth projection image inversion module further comprises a positive value contribution extraction unit, which is configured to extract the positive value contribution of the fifth image data matrix according to the fifth image data matrix.

[0091] Embodiment three

[0092] Accordingly, the embodiment of the present application provides a projection imaging device, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the projection imaging method according to the above-mentioned embodiment of the present application when executing the computer program.

[0093] Embodiment four

[0094] Accordingly, the embodiment of the present application provides a storage medium, which comprises a stored computer program, wherein the computer readable storage medium is controlled to execute the projection imaging method according to the above-mentioned embodiment of the present application when the computer program is running.

[0095] In conclusion, the present application provides a projection imaging device, equipment and storage medium, which can obtain a higher resolution projection image by using a square cross-section light source and inverting the projection image without changing the size of the light source, thereby improving the resolution of the projection image.

[0096] It should be noted that the above-described device embodiments are only schematic, and the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., they can be located in one place or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. In addition, the connection relationship between the modules in the device embodiment provided by the present application indicates that there is a communication connection between them, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0097] Those skilled in the art can clearly understand that, for the convenience and brevity, the specific working process of the above-described device can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0098] The device can be a desktop computer, a notebook, a palm computer, a cloud server and other computing devices. The device can include, but is not limited to, a processor, a memory.

[0099] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like, and is a control center of the terminal device, which connects all parts of the terminal device through various interfaces and lines.

[0100] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application program required by a function, etc.; and the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a nonvolatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory device.

[0101] The storage medium is a computer readable storage medium, and the computer program is stored in the computer readable storage medium. The computer program, when executed by a processor, can implement the steps of each method embodiment described above. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals. The above is the preferred embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the scope of protection of the present application.

Claims

1. A method of projection imaging, characterized by, The method comprises the following steps: obtaining a first projection image formed by a light source irradiating a square cross-section of a sample to be projected; wherein the resolution of the first projection image is similar to the size of the light source of the square cross-section; performing horizontal translation on the first projection image by a preset displacement to obtain a second projection image; performing vertical translation on the first projection image by a preset displacement to obtain a third projection image; performing horizontal and vertical translation on the first projection image by a preset displacement to obtain a fourth projection image; wherein the preset displacement is smaller than the size of the light source of the square cross-section; constructing a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix respectively according to the first projection image, the second projection image, the third projection image and the fourth projection image; adding the first image data matrix and the fourth image data matrix to obtain a first sum matrix; adding the second image data matrix and the third image data matrix to obtain a second sum matrix; subtracting the second sum matrix from the first sum matrix to obtain a fifth image data matrix; obtaining a fifth projection image by inversion according to the fifth image data matrix, and taking the fifth projection image as the projection image of the sample to be projected.

2. The projection imaging method of claim 1, wherein, The method of constructing a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix respectively according to the first projection image, the second projection image, the third projection image and the fourth projection image comprises the following steps: establishing a coordinate system with the top left corner of the first projection image as the coordinate origin, the horizontal direction as the x-axis and the vertical direction as the y-axis, and constructing a first image data matrix according to the coordinates of each pixel point of the first projection image in the coordinate system; constructing a second image data matrix according to the coordinates of each pixel point of the second projection image in the coordinate system; constructing a third image data matrix according to the coordinates of each pixel point of the third projection image in the coordinate system.

3. The projection imaging method of claim 1, wherein, The method of obtaining a fifth projection image by inversion according to the fifth image data matrix comprises the following steps: extracting the positive value contribution of the fifth image data matrix according to the fifth image data matrix, and then obtaining a fifth projection image by inversion according to the positive value contribution.

4. The projection imaging method of claim 3, wherein, The fifth projection image contains two projections of the sample to be projected, and the two projections fall at the two ends of the same diagonal of the fifth projection image.

5. A projection imaging apparatus characterized by comprising: The method comprises the following steps: a first projection image acquisition module, a second projection image acquisition module, a third projection image acquisition module, a fourth projection image acquisition module, an image data matrix construction module, a fifth image data matrix calculation module and a fifth projection image inversion module; the first projection image acquisition module is used for obtaining a first projection image formed by a light source irradiating a square cross-section of a sample to be projected; wherein the resolution of the first projection image is similar to the size of the light source of the square cross-section; the second projection image acquisition module is used for performing horizontal translation on the first projection image by a preset displacement to obtain a second projection image; The third projection image acquisition module is configured to vertically translate the first projection image by a preset displacement to obtain a third projection image. The fourth projection image acquisition module is configured to horizontally and vertically translate the first projection image by a preset displacement to obtain a fourth projection image, wherein the preset displacement is smaller than the size of the light source with the square cross section. The image data matrix construction module is configured to construct a first image data matrix, a second image data matrix, a third image data matrix and a fourth image data matrix according to the first projection image, the second projection image, the third projection image and the fourth projection image respectively. The fifth image data matrix calculation module is configured to add the first image data matrix and the fourth image data matrix to obtain a first sum matrix, add the second image data matrix and the third image data matrix to obtain a second sum matrix, and subtract the second sum matrix from the first sum matrix to obtain a fifth image data matrix. The fifth projection image inversion module is configured to perform inversion according to the fifth image data matrix to obtain a fifth projection image, and use the fifth projection image as the projection image of the sample to be projected.

6. The projection imaging apparatus of claim 5, wherein The fifth projection image inversion module further includes a positive value contribution extraction unit. The positive value contribution extraction unit is configured to extract positive value contribution of the fifth image data matrix according to the fifth image data matrix.

7. A projection imaging apparatus, characterized by comprising: The storage medium includes a stored computer program, wherein the computer program controls a device in which the computer readable storage medium is located to perform the projection imaging method according to any one of claims 1 to 4 when the computer program is running.

8. A storage medium, characterized by The storage medium includes a stored computer program, wherein the computer program controls a device in which the computer readable storage medium is located to perform the projection imaging method according to any one of claims 1 to 4 when the computer program is running.

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