Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in text...Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in texture image,a new color texture enhancement algorithm based on the Line Integral Convolution(LIC)for the vector field data is proposed,which combines the HSV color mapping and cumulative distribution function calculation of vector field data.This algorithm can be summarized as follows:firstly,the vector field data is convoluted twice by line integration to get the gray texture image.Secondly,the method of mapping vector data to each component of the HSV color space is established.And then,the vector field data is mapped into HSV color space and converted from HSV to RGB values to get the color image.Thirdly,the cumulative distribution function of the RGB color components of the gray texture image and the color image is constructed to enhance the gray texture and RGB color values.Finally,both the gray texture image and the color image are fused to get the color texture.The experimental results show that the proposed LIC color texture enhancement algorithm is capable of generating a better display of vector field data.Furthermore,the ambiguity of vector direction in the texture images is solved and the direction information of the vector field is expressed more accurately.展开更多
An effective approach, mapping the texture for building model based on the digital photogrammetric theory, is proposed. The easily-acquired image sequences from digital video camera on helicopter are used as texture r...An effective approach, mapping the texture for building model based on the digital photogrammetric theory, is proposed. The easily-acquired image sequences from digital video camera on helicopter are used as texture resource, and the correspondence between the space edge in building geometry model and its line feature in image sequences is determined semi-automatically. The experimental results in production of three-dimensional data for car navigation show us an attractive future both in efficiency and effect.展开更多
After a review of the planar garment effect production of pattern fabric and a brief introduction of the concept of texture mapping, the theory of 2D texture mapping onto 3D surface is stated. And the calculation proc...After a review of the planar garment effect production of pattern fabric and a brief introduction of the concept of texture mapping, the theory of 2D texture mapping onto 3D surface is stated. And the calculation procedures of texture mapping, such as texture image preprocess,mannequin and garment surface modeling, mapping relationship definition, shading/texturing model creation, and graphic transformation,are exploited to produce a real 3D garment rendring effect.Finally, the conclusion is given about the realization envlronment and affecting factors of the final images.展开更多
manufacturing(AM)technologies have been recognized for their capability to build complex components and hence have ofered more freedom to designers for a long time.The ability to directly use a computer-aided design(C...manufacturing(AM)technologies have been recognized for their capability to build complex components and hence have ofered more freedom to designers for a long time.The ability to directly use a computer-aided design(CAD)model has allowed for fabricating and realizing complicated components,monolithic design,reducing the number of components in an assembly,decreasing time to market,and adding performance or comfort-enhancing functionalities.One of the features that can be introduced for boosting a component functionality using AM is the inclusion of surface texture on a given component.This inclusion is usually a difcult task as creating a CAD model resolving fne details of a given texture is difcult even using commercial software packages.This paper develops a methodology to include texture directly on the CAD model of a target surface using a patch-based sampling texture synthesis algorithm,which can be manufactured using AM.Input for the texture generation algorithm can be either a physical sample or an image with heightmap information.The heightmap information from a physical sample can be obtained by 3D scanning the sample and using the information from the acquired point cloud.After obtaining the required inputs,the patches are sampled for texture generation according to non-parametric estimation of the local conditional Markov random feld(MRF)density function,which helps avoid mismatched features across the patch boundaries.While generating the texture,a design constraint to ensure AM producibility is considered,which is essential when manufacturing a component using,e.g.,Fused Deposition Melting(FDM)or Laser Powder Bed Fusion(LPBF).The generated texture is then mapped onto the surface using the developed distance and angle preserving mapping algorithms.The implemented algorithms can be used to map the generated texture onto a mathematically defned surface.This paper maps the textures onto fat,curved,and sinusoidal surfaces for illustration.After the texture mapping,a stereolithography(STL)model is generated with the desired texture on the target surface.The generated STL model is printed using FDM technology as a fnal step.展开更多
Texture mapping is an important technique for high -quality image generation in computer graphics. In this paper, the shortcoming of the traditional texture mapping approaches is analysed and a general bidirectional t...Texture mapping is an important technique for high -quality image generation in computer graphics. In this paper, the shortcoming of the traditional texture mapping approaches is analysed and a general bidirectional texture mapping method is proposed. Based on the bidirectional mapping, an algorithm for mapping an image to an arbitrary polygon in 3D space is given.展开更多
This paper proposes a new constructive texture synthesis steganographic scheme by compressing original secret messages.First,we divide the original message into multiple bit blocks,which are transferred to decimal val...This paper proposes a new constructive texture synthesis steganographic scheme by compressing original secret messages.First,we divide the original message into multiple bit blocks,which are transferred to decimal values and compressed into small decimal values by recording their interval sign characters.Then,a candidate pattern is generated by combining the given source pattern and boundary extension algorithm.Furthermore,we segment the candidate pattern into multiple candidate patches and use affine transformation algorithm to locate secret positions on a blank canvas,which are used to hide the sign characters by mapping the candidate patches.Finally,we select the candidate patches with minimal mean square error to represent secret bits to generate stego image by image quilting.Extensive experiments demonstrate that compared with existing texture steganographic methods,our method has a better visual quality,higher embedding capacity and security performance,while maintaining strong anti-steganalysis capability.展开更多
This paper presents an inexpensive method for self-similarity based editing of real-world 3D surface textures by using height and albedo maps. Unlike self-similarity based 2D texture editing approaches which only make...This paper presents an inexpensive method for self-similarity based editing of real-world 3D surface textures by using height and albedo maps. Unlike self-similarity based 2D texture editing approaches which only make changes to pixel color or inten- sity values, this technique also allows surface geometry and reflectance of the captured 3D surface textures to be edited and relit us- ing illumination conditions and viewing angles that differ from those of the original. A single editing operation at a given location affects all similar areas and produces changes on all images of the sample rendered under different conditions. Since surface height and albedo maps can be used to describe seabed topography and geologic features, which play important roles in many oceanic proc- esses, the proposed method can be effectively employed in applications regarding visualization and simulation of oceanic phenom- ena.展开更多
目的探究基于3.0 T MRI T2 mapping的纹理特征在膝关节骨性关节炎(keen osteoarthritis,KOA)患者不同程度软骨损伤分级中的诊断性能。材料与方法回顾性分析实验组骨性关节炎患者72个膝关节及对照组健康志愿者22个膝关节。通过矢状位T2 m...目的探究基于3.0 T MRI T2 mapping的纹理特征在膝关节骨性关节炎(keen osteoarthritis,KOA)患者不同程度软骨损伤分级中的诊断性能。材料与方法回顾性分析实验组骨性关节炎患者72个膝关节及对照组健康志愿者22个膝关节。通过矢状位T2 mapping生成T2伪彩图,在T2伪彩图中画取ROI并标记国际软骨修复学会(International Cartilage Repair Society,ICRS)分级,选取ICRS MRI分级与关节镜分级一致的201个关节面图像,采用OK软件提取、分析纹理参数。按7∶3的比例随机选取143个关节面图像作为训练集,剩余58个关节面图像作为验证集。对训练集的参数用Spearman及sbf(select by filter)进行特征过滤,用随机森林函数进行特征选择,用ctree建立模型,给出特征在鉴别正常软骨及不同软骨损伤分级中的权重。用曲线下面积(area under the curve,AUC),敏感度、特异度,准确度来评价模型预测正常软骨及不同软骨损伤分级的性能。结果MinLocation、MaxSize及Maximun3DDiameter权重均一致较大,其中MinLocation在各损伤分级中权重均最大,超过0.75。集训集中正常软骨的AUC值为0.91,Ⅰ级损伤的AUC值为0.82,Ⅱ级损伤的AUC值为0.84,Ⅲ级损伤的AUC值为0.88;验证集中正常软骨的AUC值为0.87,Ⅰ级损伤的AUC值为0.74,Ⅱ级损伤的AUC值为0.84,Ⅲ级损伤的AUC值为0.96。AUC最高的是验证集中Ⅲ级损伤软骨,为0.96;其次是训练集中正常软骨,为0.91。无论在训练集还是验证集中都表现出了良好的预测价值。敏感度最高的是训练集中Ⅰ级损伤软骨,为0.83;特异度最高的是训练集中Ⅲ级损伤软骨,为0.98。结论通过T2 mapping提取的纹理参数在不同软骨损伤程度中有较好的鉴别能力。展开更多
Textures of high-strength and low-expansion Fe-Ni alloy wires during cold-drawing processes were investigated using X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) techniques. The experimental...Textures of high-strength and low-expansion Fe-Ni alloy wires during cold-drawing processes were investigated using X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) techniques. The experimental results show that the 〈111〉 and 〈100〉 fibre textures are the main texture components, and crystalline grains in the surface are more fine and uniform than those in the center of Fe-Ni alloy wires during cold-drawing processes. It is found that the volume fraction of the 〈111〉 fibre texture component determined by quantitative regression calculation of the Gaussian distribution function reaches more than 60% and the strong 〈111〉 fibre texture component favors the torsional property of Fe-Ni alloy wires.展开更多
Texture analysis methods have been used in a variety of applications, for instance in remote sensing. Though widely used in electrical engineering, its application in atmospheric sciences is still limited. This paper ...Texture analysis methods have been used in a variety of applications, for instance in remote sensing. Though widely used in electrical engineering, its application in atmospheric sciences is still limited. This paper reviews some concepts of digital texture and statistical texture approach, applying them to a set of specific maps to analyze the correlation between texture measurements used in most papers. It is also proposed an improvement of the method by setting free a distance parameter and the use of a new texture measurement based on the Kullback-Leibler divergence. Eight statistical measurements were used: mean, contrast, standard deviation, cluster shade, cluster prominence, angular second moment, local homogeneity and Shannon entropy. The above statistical measurements were applied to simple maps and a set of rainfall fields measured with weather radar. The results indicate some high correlations, e.g. between the mean and the contrast or between the angular second moment, local homogeneity and the Shannon entropy, besides the potentiality of the method to discriminate maps.展开更多
Texture pattern mapping is one of the most important techniques for high quality image syn- thesis. It can largely enhance the visual richness of raster-scan images. In this paper is presented a new method of mapping ...Texture pattern mapping is one of the most important techniques for high quality image syn- thesis. It can largely enhance the visual richness of raster-scan images. In this paper is presented a new method of mapping planar texture pattern onto beta-spline curved surfaces——bilinear mapping method which can map planar texture pattern onto curved surfaces with less distortion, and also can fulfill the geometric transformation of the texture pattern on the curved surfaces by operating the pattern win- dow. It is valuable to both CAD/CAM in artistic field and computer graphics.展开更多
In this paper a new method of texture pattern mapping onto free-form surfaces with less distortion and higher suitability is presented.This named CF Mapping Method is based on the Ap- proximate Development Principle a...In this paper a new method of texture pattern mapping onto free-form surfaces with less distortion and higher suitability is presented.This named CF Mapping Method is based on the Ap- proximate Development Principle and Equidistance Correspondence Rule.It is adaptable to various kinds of free-form surfaces with slight warping.Especially,by operating the pattern window ,dif- ferent artistic treatments——translation,rotation,reflection,sealing,etc.can be fulfilled.Undoubt- edly,it is very practical in the CAD/CAm of artistic scope.展开更多
本文论证了超分辨率图像复原计算中的两个性质,并基于此在MAP(Maximum A Posteriori)框架下提出了一种新的纹理自适应算法.算法首先根据低分辨率图像和高分辨率图像近似计算的可类比性质计算初始图像,使初始图像的质量更高,并根据超分...本文论证了超分辨率图像复原计算中的两个性质,并基于此在MAP(Maximum A Posteriori)框架下提出了一种新的纹理自适应算法.算法首先根据低分辨率图像和高分辨率图像近似计算的可类比性质计算初始图像,使初始图像的质量更高,并根据超分辨率复原图像阶跃边缘的陡坡性质,将三边滤波正则化应用于迭代运算中,更好地保护了图像的陡坡和屋顶边缘.算法可根据图像的纹理自动计算初始图像融合参数以及正则化函数中的梯度阈值等参数,解决了以往超分辨率图像复原算法参数调整复杂的问题.实验结果表明,本文算法在没有人工参与的情况下,重建图像的客观评价和主观质量均有明显提高.展开更多
基金The National Natural Science Foundation of China under contract Nos 61702455,61672462 and 61902350the Natural Science Foundation of Zhejiang Province,China under contract No.LY20F020025。
文摘Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in texture image,a new color texture enhancement algorithm based on the Line Integral Convolution(LIC)for the vector field data is proposed,which combines the HSV color mapping and cumulative distribution function calculation of vector field data.This algorithm can be summarized as follows:firstly,the vector field data is convoluted twice by line integration to get the gray texture image.Secondly,the method of mapping vector data to each component of the HSV color space is established.And then,the vector field data is mapped into HSV color space and converted from HSV to RGB values to get the color image.Thirdly,the cumulative distribution function of the RGB color components of the gray texture image and the color image is constructed to enhance the gray texture and RGB color values.Finally,both the gray texture image and the color image are fused to get the color texture.The experimental results show that the proposed LIC color texture enhancement algorithm is capable of generating a better display of vector field data.Furthermore,the ambiguity of vector direction in the texture images is solved and the direction information of the vector field is expressed more accurately.
文摘An effective approach, mapping the texture for building model based on the digital photogrammetric theory, is proposed. The easily-acquired image sequences from digital video camera on helicopter are used as texture resource, and the correspondence between the space edge in building geometry model and its line feature in image sequences is determined semi-automatically. The experimental results in production of three-dimensional data for car navigation show us an attractive future both in efficiency and effect.
文摘After a review of the planar garment effect production of pattern fabric and a brief introduction of the concept of texture mapping, the theory of 2D texture mapping onto 3D surface is stated. And the calculation procedures of texture mapping, such as texture image preprocess,mannequin and garment surface modeling, mapping relationship definition, shading/texturing model creation, and graphic transformation,are exploited to produce a real 3D garment rendring effect.Finally, the conclusion is given about the realization envlronment and affecting factors of the final images.
基金Supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-EXC 2023 Internet of Production/390621612。
文摘manufacturing(AM)technologies have been recognized for their capability to build complex components and hence have ofered more freedom to designers for a long time.The ability to directly use a computer-aided design(CAD)model has allowed for fabricating and realizing complicated components,monolithic design,reducing the number of components in an assembly,decreasing time to market,and adding performance or comfort-enhancing functionalities.One of the features that can be introduced for boosting a component functionality using AM is the inclusion of surface texture on a given component.This inclusion is usually a difcult task as creating a CAD model resolving fne details of a given texture is difcult even using commercial software packages.This paper develops a methodology to include texture directly on the CAD model of a target surface using a patch-based sampling texture synthesis algorithm,which can be manufactured using AM.Input for the texture generation algorithm can be either a physical sample or an image with heightmap information.The heightmap information from a physical sample can be obtained by 3D scanning the sample and using the information from the acquired point cloud.After obtaining the required inputs,the patches are sampled for texture generation according to non-parametric estimation of the local conditional Markov random feld(MRF)density function,which helps avoid mismatched features across the patch boundaries.While generating the texture,a design constraint to ensure AM producibility is considered,which is essential when manufacturing a component using,e.g.,Fused Deposition Melting(FDM)or Laser Powder Bed Fusion(LPBF).The generated texture is then mapped onto the surface using the developed distance and angle preserving mapping algorithms.The implemented algorithms can be used to map the generated texture onto a mathematically defned surface.This paper maps the textures onto fat,curved,and sinusoidal surfaces for illustration.After the texture mapping,a stereolithography(STL)model is generated with the desired texture on the target surface.The generated STL model is printed using FDM technology as a fnal step.
文摘Texture mapping is an important technique for high -quality image generation in computer graphics. In this paper, the shortcoming of the traditional texture mapping approaches is analysed and a general bidirectional texture mapping method is proposed. Based on the bidirectional mapping, an algorithm for mapping an image to an arbitrary polygon in 3D space is given.
基金supported by Natural Science Foundation of China under Grants(U1736120,61602295).
文摘This paper proposes a new constructive texture synthesis steganographic scheme by compressing original secret messages.First,we divide the original message into multiple bit blocks,which are transferred to decimal values and compressed into small decimal values by recording their interval sign characters.Then,a candidate pattern is generated by combining the given source pattern and boundary extension algorithm.Furthermore,we segment the candidate pattern into multiple candidate patches and use affine transformation algorithm to locate secret positions on a blank canvas,which are used to hide the sign characters by mapping the candidate patches.Finally,we select the candidate patches with minimal mean square error to represent secret bits to generate stego image by image quilting.Extensive experiments demonstrate that compared with existing texture steganographic methods,our method has a better visual quality,higher embedding capacity and security performance,while maintaining strong anti-steganalysis capability.
文摘This paper presents an inexpensive method for self-similarity based editing of real-world 3D surface textures by using height and albedo maps. Unlike self-similarity based 2D texture editing approaches which only make changes to pixel color or inten- sity values, this technique also allows surface geometry and reflectance of the captured 3D surface textures to be edited and relit us- ing illumination conditions and viewing angles that differ from those of the original. A single editing operation at a given location affects all similar areas and produces changes on all images of the sample rendered under different conditions. Since surface height and albedo maps can be used to describe seabed topography and geologic features, which play important roles in many oceanic proc- esses, the proposed method can be effectively employed in applications regarding visualization and simulation of oceanic phenom- ena.
文摘目的探究基于3.0 T MRI T2 mapping的纹理特征在膝关节骨性关节炎(keen osteoarthritis,KOA)患者不同程度软骨损伤分级中的诊断性能。材料与方法回顾性分析实验组骨性关节炎患者72个膝关节及对照组健康志愿者22个膝关节。通过矢状位T2 mapping生成T2伪彩图,在T2伪彩图中画取ROI并标记国际软骨修复学会(International Cartilage Repair Society,ICRS)分级,选取ICRS MRI分级与关节镜分级一致的201个关节面图像,采用OK软件提取、分析纹理参数。按7∶3的比例随机选取143个关节面图像作为训练集,剩余58个关节面图像作为验证集。对训练集的参数用Spearman及sbf(select by filter)进行特征过滤,用随机森林函数进行特征选择,用ctree建立模型,给出特征在鉴别正常软骨及不同软骨损伤分级中的权重。用曲线下面积(area under the curve,AUC),敏感度、特异度,准确度来评价模型预测正常软骨及不同软骨损伤分级的性能。结果MinLocation、MaxSize及Maximun3DDiameter权重均一致较大,其中MinLocation在各损伤分级中权重均最大,超过0.75。集训集中正常软骨的AUC值为0.91,Ⅰ级损伤的AUC值为0.82,Ⅱ级损伤的AUC值为0.84,Ⅲ级损伤的AUC值为0.88;验证集中正常软骨的AUC值为0.87,Ⅰ级损伤的AUC值为0.74,Ⅱ级损伤的AUC值为0.84,Ⅲ级损伤的AUC值为0.96。AUC最高的是验证集中Ⅲ级损伤软骨,为0.96;其次是训练集中正常软骨,为0.91。无论在训练集还是验证集中都表现出了良好的预测价值。敏感度最高的是训练集中Ⅰ级损伤软骨,为0.83;特异度最高的是训练集中Ⅲ级损伤软骨,为0.98。结论通过T2 mapping提取的纹理参数在不同软骨损伤程度中有较好的鉴别能力。
文摘Textures of high-strength and low-expansion Fe-Ni alloy wires during cold-drawing processes were investigated using X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) techniques. The experimental results show that the 〈111〉 and 〈100〉 fibre textures are the main texture components, and crystalline grains in the surface are more fine and uniform than those in the center of Fe-Ni alloy wires during cold-drawing processes. It is found that the volume fraction of the 〈111〉 fibre texture component determined by quantitative regression calculation of the Gaussian distribution function reaches more than 60% and the strong 〈111〉 fibre texture component favors the torsional property of Fe-Ni alloy wires.
文摘Texture analysis methods have been used in a variety of applications, for instance in remote sensing. Though widely used in electrical engineering, its application in atmospheric sciences is still limited. This paper reviews some concepts of digital texture and statistical texture approach, applying them to a set of specific maps to analyze the correlation between texture measurements used in most papers. It is also proposed an improvement of the method by setting free a distance parameter and the use of a new texture measurement based on the Kullback-Leibler divergence. Eight statistical measurements were used: mean, contrast, standard deviation, cluster shade, cluster prominence, angular second moment, local homogeneity and Shannon entropy. The above statistical measurements were applied to simple maps and a set of rainfall fields measured with weather radar. The results indicate some high correlations, e.g. between the mean and the contrast or between the angular second moment, local homogeneity and the Shannon entropy, besides the potentiality of the method to discriminate maps.
文摘Texture pattern mapping is one of the most important techniques for high quality image syn- thesis. It can largely enhance the visual richness of raster-scan images. In this paper is presented a new method of mapping planar texture pattern onto beta-spline curved surfaces——bilinear mapping method which can map planar texture pattern onto curved surfaces with less distortion, and also can fulfill the geometric transformation of the texture pattern on the curved surfaces by operating the pattern win- dow. It is valuable to both CAD/CAM in artistic field and computer graphics.
文摘In this paper a new method of texture pattern mapping onto free-form surfaces with less distortion and higher suitability is presented.This named CF Mapping Method is based on the Ap- proximate Development Principle and Equidistance Correspondence Rule.It is adaptable to various kinds of free-form surfaces with slight warping.Especially,by operating the pattern window ,dif- ferent artistic treatments——translation,rotation,reflection,sealing,etc.can be fulfilled.Undoubt- edly,it is very practical in the CAD/CAm of artistic scope.
文摘本文论证了超分辨率图像复原计算中的两个性质,并基于此在MAP(Maximum A Posteriori)框架下提出了一种新的纹理自适应算法.算法首先根据低分辨率图像和高分辨率图像近似计算的可类比性质计算初始图像,使初始图像的质量更高,并根据超分辨率复原图像阶跃边缘的陡坡性质,将三边滤波正则化应用于迭代运算中,更好地保护了图像的陡坡和屋顶边缘.算法可根据图像的纹理自动计算初始图像融合参数以及正则化函数中的梯度阈值等参数,解决了以往超分辨率图像复原算法参数调整复杂的问题.实验结果表明,本文算法在没有人工参与的情况下,重建图像的客观评价和主观质量均有明显提高.