Medical Ultrasound Data Photorealistic Visualization Method and System Based on Half-width Segmentation

Abstract

The present invention discloses a method and system for realistic visualization of medical ultrasound data based on half-angle segmentation, belonging to the field of computer image technology. It includes: obtaining medical ultrasound volume data, processing the medical ultrasound volume data through a half-angle segmentation algorithm to obtain a set of two-dimensional slices; introducing a light source into the visualization scene, calculating the indirect illumination, direct illumination, specular highlights and ambient light of each two-dimensional slice in the set of two-dimensional slices and synthesizing a global illumination term to render the two-dimensional slices; synthesizing the rendered two-dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image. It can make the rendering result have a realistic skin texture and shadow, which is convenient for doctors to diagnose; and solves the problem that the existing visualization images cannot give doctors a good sense of depth and space perception.

Description

Technical Field

[0001] The present invention relates to the field of computer image technology, and particularly to a method and system for realistic visualization of medical ultrasound data based on half-angle segmentation. Background Art

[0002] The statements in this section merely mention the background art related to the present invention and do not necessarily constitute prior art.

[0003] The ultrasound data collected in medical applications often has the characteristic of low signal-to-noise ratio. Understanding such data is a core difficulty in ultrasound technology. Doctors often need to undergo a large amount of training to make accurate medical diagnoses from 2D ultrasound images, which incurs a relatively high learning cost and increases the difficulty of doctor-patient communication.

[0004] With the rapid development of hardware devices, existing advanced ultrasound devices can already support real-time acquisition and reconstruction of 3D / 4D data, bringing more possibilities for ultrasound data analysis. Since the spatio-temporal resolution of ultrasound acquisition has approached the physical limit, the focus of ultrasound technology development has gradually shifted towards data visualization technology. Advanced visualization technology can convert complex ultrasound data into images in real time, which can not only reduce the learning cost of diagnosis but also enhance users' spatial perception and understanding of the overall structure of ultrasound data by combining realistic lighting information.

[0005] Currently, the visualization results presented by traditional 3D ultrasound modes do not consider the light and shadow of the scene and the subsurface scattering effect of the interaction between the skin and light, resulting in a lack of realistic texture and lighting shadow details of the skin in the results, unable to give doctors a good sense of depth and space, and also difficult to facilitate doctor-patient communication. Summary of the Invention

[0006] To solve the deficiencies of the prior art, the present invention provides a method, system, electronic device, computer-readable storage medium, and computer program product for realistic visualization of medical ultrasound data based on half-angle segmentation. A light source is introduced into the visualization scene of medical ultrasound data for lighting calculation, and the calculated lighting information is used through the half-angle segmentation algorithm to synthesize the final rendering result, so that the rendering result has a realistic skin texture and shadow.

[0007] In the first aspect, the present invention provides a method for realistic visualization of medical ultrasound data based on half-angle segmentation;

[0008] A method for realistic visualization of medical ultrasound data based on half-angle segmentation includes:

[0009] Obtain medical ultrasound volume data, and process the medical ultrasound volume data through a half-angle segmentation algorithm to obtain a set of two-dimensional slices;

[0010] Introduce a light source into the visualization scene, calculate the indirect illumination, direct illumination, specular highlight, and ambient light of each two-dimensional slice in the set of two-dimensional slices, and synthesize a global illumination term to render the two-dimensional slice;

[0011] Synthesize the rendered two-dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image.

[0012] In some embodiments, it further includes:

[0013] Obtain the isosurface value to be displayed and the thickness of the contour gradient region, and determine the opacity corresponding to each voxel in the synthesized image according to the isosurface value and the thickness of the contour gradient region to perform contour rendering on the synthesized image.

[0014] In some embodiments, the process of obtaining the set of two-dimensional slices by processing the medical ultrasound volume data through the half-angle slicing algorithm specifically includes:

[0015] Calculate the half-way vector between the light source direction and the viewing direction;

[0016] Determine the edge stepping order and spacing of the slice according to the half-way vector and the volume data bounding box; determine the stepping length of the slice according to the edge stepping order and spacing of the slice to perform stepped slicing and store the set of two-dimensional slice vertices.

[0017] In some embodiments, when calculating the indirect illumination of each two-dimensional slice, filtering processing is performed through a random sampling method based on perturbed textures and the scaling of the filter kernel.

[0018] In some embodiments, when synthesizing the rendered two-dimensional slices, each voxel on the two-dimensional slice is sampled point-offset along the viewing direction according to the noise texture pixel value.

[0019] In some embodiments, when synthesizing the rendered two-dimensional slices, adjacent two-dimensional slices are fused through a temporal supersampling method.

[0020] In a second aspect, the present invention provides a medical ultrasound data realistic visualization system based on half-angle slicing;

[0021] A medical ultrasound data realistic visualization system based on half-angle slicing, comprising:

[0022] A half-angle slicing module, configured to: obtain medical ultrasound volume data, and process the medical ultrasound volume data through a half-angle slicing algorithm to obtain a set of two-dimensional slices;

[0023] A lighting calculation module, configured to: introduce a light source into a visualization scene, calculate the indirect lighting, direct lighting, specular highlights, and ambient light of each two-dimensional slice in the set of two-dimensional slices, and synthesize a global lighting term to render the two-dimensional slice;

[0024] A rendering synthesis module, configured to: synthesize the rendered two-dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image.

[0025] In a third aspect, the present invention provides an electronic device;

[0026] An electronic device includes a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the above-mentioned method for realistic visualization of medical ultrasound data based on half-angle segmentation.

[0027] In a fourth aspect, the present invention provides a computer-readable storage medium;

[0028] A computer-readable storage medium, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, the steps of the above-mentioned method for realistic visualization of medical ultrasound data based on half-angle segmentation are implemented.

[0029] In a fifth aspect, the present invention provides a computer program product;

[0030] A computer program product includes a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the above-mentioned method for realistic visualization of medical ultrasound data based on half-angle segmentation are implemented.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The technical solution provided by the present invention introduces a light source into the visualization scene of medical ultrasound data, realizes effects such as soft shadows, color diffusion, and subsurface scattering by simulating multiple scattering of light, and synthesizes the final rendering result using the calculated lighting information through the half-angle segmentation algorithm, so that the rendering result has a realistic skin texture and shadow.

[0033] 2. The technical solution provided by the present invention proposes a special contour rendering mode, which only renders the internal and external tissue contours of the data, so as to highlight the abnormalities in the development of tissue structures and facilitate the diagnosis of doctors.

[0034] 3. The technical solution provided by the present invention can maintain high performance in controlling the softness and hardness of shadows through the random sampling technology based on perturbed textures, and reduce the moiré defects in static and dynamic images through the temporal supersampling technology and the random jitter technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0036] Figure 1 The flowchart of the method for visualizing medical ultrasound data with a sense of reality based on half - angle segmentation provided by the embodiments of the present invention, where represents addition, represents multiplication;

[0037] Figure 2 The flowchart of the update process of indirect lighting provided by the embodiments of the present invention. Detailed implementation manners

[0038] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0039] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "comprising" and "having" and any variations thereof are intended to cover non - exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0040] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0041] Embodiment 1

[0042] The visualization images of existing medical ultrasound data lack a sense of reality and are not conducive to doctors' diagnosis. Therefore, the present invention provides a method for visualizing medical ultrasound data with a sense of reality based on half - angle segmentation, which realizes the rendering and synthesis of medical ultrasound data through the combination of a lighting calculation model and a half - angle segmentation algorithm.

[0043] Next, in combination with Figure 1 - Figure 2 , a method for visualizing medical ultrasound data with a sense of reality based on half - angle segmentation disclosed in this embodiment will be described in detail. The method for visualizing medical ultrasound data with a sense of reality based on half - angle segmentation includes the following steps:

[0044] S1. Obtain medical ultrasound volume data, and process the medical ultrasound volume data through a half-angle slicing algorithm to obtain a set of two-dimensional slices.

[0045] In this embodiment, the medical ultrasound volume data is represented by a set of proxy polygons through the half-angle slicing algorithm, and each polygon represents a half-angle slice. As an implementation manner, S1 specifically includes:

[0046] S101. Obtain the light source direction and the viewing direction , and calculate the half-way vector between the light source direction and the viewing direction .

[0047] Here, the light source direction and the viewing direction are input by the user; specifically, calculate the unit vectors of the light source direction and the viewing direction respectively, then add the two unit vectors and perform normalization processing to obtain the half-way vector between the light source direction and the viewing direction .

[0048] S102. Use the half-angle slicing algorithm to process the half-way vector and the ultrasound volume data to calculate a set of vertex sets of two-dimensional slices.

[0049] Specifically, the half-angle slicing process can be summarized as finding the intersection points of the slice and the bounding box of the volume data . The bounding box is centered at the origin. First, take the dot product of the eight vertex coordinates of the bounding box with the half-way vector respectively to obtain the projection distance of each vertex relative to the origin in the direction, record the nearest and the farthest distances. Since it is the distance relative to the origin, the nearest distance obtained is negative. Subtract the nearest distance from the farthest distance and divide by the number of slices to obtain the slice spacing ; Next, find the projection of each edge on the bounding box of the volume data in the direction of the half-way vector to obtain the possible intersection range of each edge with the slice. Find the projection of the slice spacing on each edge to obtain the step length of the slice on each edge; Finally, start stepping the slice according to the step length , and sequentially determine which edges each slice intersects with, and store all the intersection points generated by the slice with .

[0050] S2. Introduce the light source into the visualization scene, calculate the indirect illumination, direct illumination, specular highlight, and ambient light of each two-dimensional slice in the two-dimensional slice set and synthesize the global illumination term to render the two-dimensional slice.

[0051] Among them, the indirect illumination and direct illumination are stored through two different shadow maps, and the specular highlight and ambient light are calculated in real time during the stage of synthesizing the global illumination term.

[0052] In order to restore the true texture and illumination shadow details of the skin, calculate the illumination information. As an implementation manner, S2 specifically includes:

[0053] S201. Obtain the softness / hardness of the shadow, the voxel opacity, and the attenuation coefficient of the colored light, and calculate the indirect illumination.

[0054] Since the tissue structure in the human body is very complex, after the light enters the skin, it will change the propagation path multiple times and finally leave the skin and reach the viewing point, that is, subsurface scattering; therefore, in this embodiment, color the volume data through indirect illumination and implement the multiple scattering and soft shadow effects.

[0055] Specifically, use a set of constant attenuation coefficients of the colored light , during the propagation of the light, attenuate the RGB color components of the light to different degrees to simulate this phenomenon, and enhance the diffusion effect of the color by filtering the voxel opacity to obtain the color information and attenuation information of the light during the propagation process.

[0056] Use a shadow map to store the color information and attenuation information of the light during the propagation process. For the colored light, each color component will have different degrees of attenuation during the forward process. The first three channels of the shadow map are used to store the attenuated color information of the light during the forward process; filter the voxel opacity to enhance the diffusion effect of the color, and the fourth channel of the shadow map is used to store the filtered voxel opacity; approximate the subsurface scattering effect by blurring the light color to simulate the forward scattering process of the light, and enhance the diffusion of the shadow color by blurring the attenuation coefficient of the light.

[0057] Among them, the color information of the light during the propagation process is expressed as:

[0058] ;

[0059] The attenuation information of the light during the propagation process is expressed as:

[0060] ;

[0061] Among them, represents the viewing direction, represents the light source direction, represents the spacing between slices, represents the RGB channels of the indirect illumination shadow map, represents the Alpha channel of the indirect illumination, represents the color / attenuation information of the indirect illumination shadow map at the point after the represents the convolution operation, represents the filter kernel, represents the previously mentioned constant attenuation coefficient of the colored light, represents the opacity of the volume data at the point , represents the th, that is, the color / attenuation information of the indirect illumination shadow map at the point after the previous update, and this information will be used in the next update, that is, when calculating .

[0062] In the calculation of indirect illumination, in order to simulate the effect of forward scattering, in this embodiment, the result of subsurface scattering is approximated by averaging the light intensity, that is, the illumination information is blurred during the propagation of the light; in order to freely control the softness / hardness of the generated shadow and the degree of color diffusion, in this embodiment, the size of the filter kernel for blurring the illumination information is adjusted.

[0063] Furthermore, in order to ensure the same performance when the softness / hardness of the shadow is different, in the implementation of filtering, a random sampling method based on perturbed texture is selected.

[0064] Specifically, a two-channel 512x512 noise texture, that is, a perturbed texture, is generated. Each pixel in the perturbed texture is a two-dimensional offset, and the range of each component of the two-dimensional offset is . When blurring the indirect illumination shadow map, first randomly sample the perturbed texture (the coordinates for randomly sampling the perturbed texture are , is the current sample subscript, is the texture coordinate of this voxel), offset the coordinates of the current shadow map according to the result of randomly sampling the perturbed texture, sample indirect illumination samples (the current value is 8), and at the same time scale the offset using the previously mentioned filter kernel size . The weights of the samples are selected as follows: the initial sample weight is 1.0, and the weights of all subsequent samples are 0.8.

[0065] The calculation formula for the filter kernel size is as follows:

[0066] ;

[0067] Among them, represents the spacing of the slices, represents the softness / hardness of the shadow, which is determined by the user.

[0068] Here, the resolution of the shadow map is 1024×512.

[0069] S202. Calculate the direct illumination and store it in the shadow map.

[0070] The light starts from the light source and reaches the viewpoint after one scattering, that is, single scattering. The direct illumination is responsible for implementing hard shadows and providing the light intensity information for the calculation of the specular term. It is necessary to maintain a shadow map to record the attenuation of the light intensity, but it is not necessary to record the color information of the light.

[0071] Specifically, the shadow map of the direct illumination can be understood as a series of parallel light rays passing through the volume data and being absorbed by the volume data. Assuming that the light ray propagates from point to point in the direction , then its attenuated intensity can be expressed as:

[0072] ;

[0073] In the formula, represents the light intensity of the light ray propagating to point in the direction , is called the optical depth. When the spacing of the volume data is small enough, this exponential term can be approximated as , that is, the transparency of the volume data. Among them, is the opacity of the voxel at point ; represents the extinction term, which is the probability of the light ray being scattered or absorbed; represents the integration variable.

[0074] Each time the shadow map of the direct illumination is updated, it only needs to multiply the original light intensity by the transparency of the volume data for attenuation calculation.

[0075] Here, the resolution of the shadow map is 1024×512.

[0076] S203. Calculate the specular highlights.

[0077] A portion of the light hitting the skin surface is directly reflected back to the viewing point, i.e., specular reflection. The specular highlight can add a smooth and moist feeling to the skin and enhance the perception of the edges of the structure. The specular highlight also belongs to the category of single scattering, so it is linked to the illumination intensity of the direct light. In this embodiment, the calculation of the specular highlight uses the Blinn - phong model approximation, which is expressed as:

[0078] ;

[0079] where, represents the light intensity stored in the direct light shadow map corresponding to point , represents the half - vector between the viewing direction and the light source direction, represents the normal vector at point , approximated using the gradient vector, represents the specular coefficient. The larger the specular coefficient, the narrower the specular highlight range, and the smaller the specular coefficient, the wider the specular highlight range.

[0080] S204. Calculate the ambient light. The specific process is as follows:

[0081] In the two - dimensional slice space, each sample projects light in several surrounding directions, and the light has an artificially defined initial intensity. First, take several sample steps and calculate the attenuation of the light intensity according to the following formula:

[0082] ;

[0083] where, represents the sample position, represents the final intensity of a single ray after attenuation, represents the sample distance from the artificially defined constant light intensity in the direction, represents the step length of the light, here take , represents the constant exponent for adjusting the voxel opacity, i.e., a hyper - parameter. Selecting an appropriate to adjust the voxel sample intensity can better control the display effect of the ambient light, refers to the opacity of the voxel at point .

[0084] In this embodiment, = 0.75.

[0085] Finally, take the mean of the light intensity, and in order to highlight the edge features of the volume data, take the power of the average intensity as the ambient light term, i.e.:

[0086] ;

[0087] Take , , , , and take the samples to decay in four directions of x, -x, y, -y in the slice space.

[0088] S205. Linearly combine the indirect illumination, direct illumination, specular highlight, and ambient light to synthesize the global illumination term, and render the two-dimensional slice.

[0089] Among them, the global illumination term is expressed as:

[0090] ;

[0091] Among them, is the albedo at point , that is, the ratio of direct illumination to indirect illumination, is the indirect illumination term, is the direct illumination term, is the specular highlight term, is the weight controlling the specular highlight brightness, is the ambient light term.

[0092] Then, multiply the base reflection color of the two-dimensional slice voxels by the global illumination term to obtain the final coloring of the slice, which is expressed as:

[0093] .

[0094] S3. Synthesize the rendered two-dimensional slices according to the light source direction and the viewing direction to obtain the synthesized image.

[0095] When a slice is rendered, it needs to be synthesized with the previously rendered slices. According to the light source direction and the viewing direction, there are mainly two synthesis methods.

[0096] Specifically, when the included angle between the light source direction and the viewing direction is an acute angle, the backward synthesis method is adopted, which is expressed as:

[0097] ;

[0098] ;

[0099] In the formula, represents the color updated at the th time, represents the opacity updated at the th time, represents the base reflection color of the two-dimensional slice voxels, represents the point Opacity at indicates the th time, i.e., the color of the previous update, indicates the th time, i.e., the opacity of the previous update.

[0100] When the included angle between the light source direction and the viewing direction is an obtuse angle, i.e., when the light source is behind the volume data, the forward synthesis method is adopted, which is expressed as:

[0101] ;

[0102] ;

[0103] Here, and are obtained by calculating the transfer function. The transfer function used is a simple linear function of the first order, which is expressed as:

[0104] ;

[0105] ;

[0106] Among them, is the voxel intensity of the original two-dimensional slice, is the skin reflection color, , respectively represent constants.

[0107] In the slice-based rendering method, the number of slices is equal to the sampling rate. A lower number of slices, i.e., a lower sampling rate, will cause severe aliasing in volume rendering in the form of ripples, also known as wood grain artifacts. To eliminate wood grain artifacts, when rendering each frame of two-dimensional slices, whether it is a dynamic scene or a static scene, random jitter technology is used in the global illumination synthesis stage to reduce wood grain artifacts; if it is a static scene, the time super-sampling technology is combined to fuse the two nearest frames of images to further eliminate wood grain artifacts.

[0108] To effectively increase the sampling rate to eliminate wood grain without increasing performance overhead, as an implementation, the time super-sampling technology and random jitter technology are combined to eliminate wood grain artifacts in static images.

[0109] Specifically, when the image is static, i.e., no parameters change, two frames are accumulated and fused. The first frame is rendered with normal parameters, and the second frame offsets the slice positions to the midpoint between two slices in the first frame, so as to sample the volume data positions that were not sampled in the first frame. The two rendering results are fused proportionally, and most visible wood grains can be eliminated to obtain high-quality results.

[0110] The temporal supersampling technique can eliminate most of the moiré artifacts in static images. However, during user interaction, the scene is dynamic, and the temporal supersampling technique is not applicable to moiré elimination in dynamic scenes. As an implementation, only the random dithering technique is used to eliminate moiré artifacts in dynamic images.

[0111] Specifically, a noise texture is used and tiled on each half-angle slice. Each voxel on the half-angle slice samples the offset of the sampling point along the viewing direction according to the value of the corresponding noise texture pixel (it is necessary to ensure that the same pixels on the slice have the same dithering amount during one rendering process). By offsetting the sampling point, the regular moiré can be scattered and turned into noise with a better visual effect. In this way, a large performance overhead is avoided, and noise is introduced to improve the quality of the rendering result.

[0112] Currently, a 32×32 noise texture is tiled on the screen space to perform dithering on each pixel, and the random number range of the noise texture is , i.e., the random dithering coefficient.

[0113] To perform contour rendering on different structures contained in the ultrasound volume data, in some embodiments, it further includes: obtaining the isosurface value to be displayed and the thickness of the contour gradient region, and determining the opacity corresponding to each voxel in the composite image according to the isosurface value and the thickness of the contour gradient region, so as to perform contour rendering on the composite image.

[0114] Specifically, an isodensity surface or an isosurface can be used to represent the surface information of the volume data. By adjusting the opacity of each voxel of the volume data, the opacity of the voxels far from the isosurface value is lowered, and the opacity of the voxels close to the isosurface value is raised, so that the contour of the isosurface corresponding to a specific value in the volume data can be fully displayed. At the same time, it is also necessary to add a gradient of opacity within a certain neighborhood range of the isosurface value to avoid the problems of isosurface confusion and jaggedness caused by data precision. The opacity is expressed as: Within the formula,

[0115] represents the opacity of the contour,

[0116] ;

[0117] In the formula, represents the opacity of the contour, represents the isosurface value to be displayed, represents the required thickness of the contour gradient region, and all three can be freely set according to requirements; represents the magnitude of the gradient vector at point , represents the voxel opacity at point , Representative point The original density of the volume data at the location.

[0118] Embodiment 2

[0119] This embodiment discloses a medical ultrasound data realistic visualization system based on half - angle segmentation, including:

[0120] A half - angle segmentation module, configured to: obtain medical ultrasound volume data, process the medical ultrasound volume data through a half - angle segmentation algorithm, and obtain a set of two - dimensional slices;

[0121] A lighting calculation module, configured to: introduce a light source into the visualization scene, calculate the indirect lighting, direct lighting, specular highlights, and ambient light of each two - dimensional slice in the set of two - dimensional slices and synthesize a global lighting term to render the two - dimensional slices;

[0122] A rendering synthesis module, configured to: synthesize the rendered two - dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image.

[0123] It should be noted here that the above - mentioned half - angle segmentation module, lighting calculation module, and rendering synthesis module correspond to the steps in Embodiment 1. The examples and application scenarios implemented by the above - mentioned modules and the corresponding steps are the same, but are not limited to the content disclosed in Embodiment 1. It should be noted that the above - mentioned modules, as part of the system, can be executed in a computer system such as a set of computer - executable instructions.

[0124] Embodiment 3

[0125] Embodiment 3 of the present invention provides an electronic device, including a memory and a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of the above - mentioned medical ultrasound data realistic visualization method based on half - angle segmentation are completed.

[0126] Embodiment 4

[0127] Embodiment 4 of the present invention provides a computer - readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the steps of the above - mentioned medical ultrasound data realistic visualization method based on half - angle segmentation are completed.

[0128] Embodiment 5

[0129] Embodiment 5 of the present invention provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the above - mentioned medical ultrasound data realistic visualization method based on half - angle segmentation are implemented.

[0130] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and combinations of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device generate a means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0131] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing device to perform a series of operational steps on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0133] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0134] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for realistic visualization of medical ultrasound data based on half-width segmentation, characterized in that Comprising: Obtain medical ultrasound volume data, process the medical ultrasound volume data through a half - angle slicing algorithm to obtain a set of two - dimensional slices; Introduce a light source into the visualization scene, calculate the indirect illumination, direct illumination, specular highlight, and ambient light of each two - dimensional slice in the set of two - dimensional slices and synthesize a global illumination term to render the two - dimensional slices; Among them, when calculating the indirect illumination of each two - dimensional slice, perform filtering processing through a random sampling method based on perturbed texture and the scaling of the filter kernel; the calculation formula for the filter kernel size is expressed as: ； In the formula, represents the spacing of the slices, represents the softness and hardness of the shadow, which is determined by the user; Synthesize the rendered two - dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image; When synthesizing the rendered two - dimensional slices, in a dynamic scene, use the random jitter technique to eliminate the wood grain artifacts in the dynamic picture, and combine the temporal supersampling technique and the random jitter technique to eliminate the wood grain artifacts in the static picture; the random jitter technique is specifically: sample point offset each voxel on the two - dimensional slice along the viewing direction according to the noise texture pixel value, and the temporal supersampling technique is to proportionally fuse two different rendering results; Obtain the isosurface value to be displayed and the thickness of the contour gradient region, and determine the opacity corresponding to each voxel in the synthesized image according to the isosurface value and the thickness of the contour gradient region to perform contour rendering on the synthesized image; The opacity is expressed as: ； In the formula, represents the opacity of the contour, represents the isosurface value to be displayed, represents the thickness of the contour gradient region required, and all three can be freely set according to requirements; represents the point at the magnitude of the gradient vector, represents the point at the voxel opacity, represents the point at the original density of the volume data.

2. The method for realistic visualization of medical ultrasound data based on half - angle segmentation according to claim 1, characterized in that, The process of processing the medical ultrasound volume data through the half - angle slicing algorithm to obtain a set of two - dimensional slices specifically includes: Calculate the half - vector between the light source direction and the viewing direction; Determine the edge stepping order and spacing of the slice according to the half - vector and the volume data bounding box; determine the stepping length of the slice according to the edge stepping order and spacing of the slice to perform stepped slicing and store the two - dimensional slice vertex set.

3. A medical ultrasound data photorealistic visualization system based on half-width segmentation, characterized in that Comprising: A half - angle slicing module, configured to: obtain medical ultrasound volume data, process the medical ultrasound volume data through a half - angle slicing algorithm to obtain a set of two - dimensional slices; A lighting calculation module, configured to: introduce a light source into the visualization scene, calculate the indirect illumination, direct illumination, specular highlight, and ambient light of each two - dimensional slice in the set of two - dimensional slices and synthesize a global illumination term to render the two - dimensional slices; Among them, when calculating the indirect illumination of each two - dimensional slice, perform filtering processing through a random sampling method based on perturbed texture and the scaling of the filter kernel; the calculation formula for the filter kernel size is expressed as: ； In the formula, represents the spacing of the slices, represents the softness and hardness of the shadow, which is determined by the user; A rendering synthesis module, configured to: synthesize the rendered two - dimensional slices according to the light source direction and the viewing direction to obtain a synthesized image; When synthesizing the rendered two - dimensional slices, in a dynamic scene, use the random jitter technique to eliminate the wood grain artifacts in the dynamic picture, and combine the temporal supersampling technique and the random jitter technique to eliminate the wood grain artifacts in the static picture; the random jitter technique is specifically: sample point offset each voxel on the two - dimensional slice along the viewing direction according to the noise texture pixel value, and the temporal supersampling technique is to proportionally fuse two different rendering results; Obtain the isovalue to be displayed and the thickness of the contour gradient region. According to the isovalue and the thickness of the contour gradient region, determine the opacity corresponding to each voxel in the composite image, so as to perform contour rendering on the composite image; The opacity is expressed as: ； In the formula, represents the opacity of the contour, represents the isosurface value to be displayed, represents the thickness of the contour gradient region required, and all three can be freely set according to requirements; represents the point at the magnitude of the gradient vector, represents the point at the voxel opacity, represents the point at the original density of the volume data.

4. An electronic device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, The processor executes the computer program to implement the steps of the method for realistic visualization of medical ultrasound data based on half-angle segmentation according to any one of claims 1-2.

5. A computer-readable storage medium having computer programs / instructions stored thereon, characterized in that, When the computer program / instructions are executed by a processor, the steps of the method for realistic visualization of medical ultrasound data based on half-angle segmentation according to any one of claims 1-2 are implemented.

6. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by a processor, the steps of the method for realistic visualization of medical ultrasound data based on half-angle segmentation according to any one of claims 1-2 are implemented.

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