Texture synthesis has been developed for several years.The traditional technique can generate a larger image from a small image while avoid feeling of repetition or uncontinuity.Some constrained synthesis methods whic...Texture synthesis has been developed for several years.The traditional technique can generate a larger image from a small image while avoid feeling of repetition or uncontinuity.Some constrained synthesis methods which can synthesize image according to special location demand or other demands have been also proposed in recent years.However,in general,these constrained texture synthesis methods are simple and have few controllable factors to meet user＇s diverse needs.To control multiple-sample texture synthesis more flexibly in various aspects such as synthesis location,proportion and semantic objects,we present an interactive texture synthesis approach based on circular patches and constrained by objects according to a certain ratio.With this approach,source exemplars and the target image are firstly divided into several regions with different characters.Users can click the blocks in the source exemplars and the want-to-be-synthesized region in the target image,and then texture in the target image is synthesized with the corresponding regions in the source exemplars.In the process of texture synthesis,circular patch instead of square patch is used to eliminate the aliasing phenomena.Images are synthesized from multiple sample images with ratio constraint and experiments on images show that our approach can get effective results of ratio-constrained multi-sample synthesis.展开更多
A new algorithm is proposed for completing the missing parts caused by the removal of foreground or background elements from an image of natural scenery in a visually plausible way. The major contributions of the prop...A new algorithm is proposed for completing the missing parts caused by the removal of foreground or background elements from an image of natural scenery in a visually plausible way. The major contributions of the proposed algorithm are： （1） for most natural images, there is a strong orientation of texture or color distribution. So a method is introduced to compute the main direction of the texture and complete the image by limiting the search to one direction to carry out image completion quite fast; （2） there exists a synthesis ordering for image completion. The searching order of the patches is defined to ensure the regions with more known information and the structures should be completed before filling in other regions; （3） to improve the visual effect of texture synthesis, an adaptive scheme is presented to determine the size of the template window for capturing the features of various scales. A number of examples are given to demonstrate the effectiveness of the proposed algorithm.展开更多
Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images...Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images,and is hard to guarantee security.To solve these problems,steganography using reversible texture synthesis based on seeded region growing and LSB is proposed.Secret information is embedded in the process of synthesizing texture image from the existing natural texture.Firstly,we refine the visual effect.Abnormality of synthetic texture cannot be fully prevented if no approach of controlling visual effect is applied in the process of generating synthetic texture.We use seeded region growing algorithm to ensure texture’s similar local appearance.Secondly,the size and capacity of image can be decreased by introducing the information segmentation,because the capacity of the secret information is proportional to the size of the synthetic texture.Thirdly,enhanced security is also a contribution in this research,because our method does not need to transmit parameters for secret information extraction.LSB is used to embed these parameters in the synthetic texture.展开更多
In this paper,a novel concept of multilayer synthesis and a general framework for texture synthesis method are presented.Within this framework,we first decompose the texture into the supposed pattern layer and materia...In this paper,a novel concept of multilayer synthesis and a general framework for texture synthesis method are presented.Within this framework,we first decompose the texture into the supposed pattern layer and material layer in the frequency domain by an E-texton extracting algorithm,then manipulate and extend them respectively according to their own personalities,and finally merge the newly synthesized pattern layer and material layer again to generate the final output.Experiment results show that our method not only greatly improves the synthesis quality for those cases that single-layer synthesis cannot handle well but also provides an ability of achieving various special synthesis effects.展开更多
Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometr...Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometry and image texture synthesis to solve these problems. We have improved Wei and Levoy (2000)’s texture synthesis algorithm by first using two-dimensional autocorrelation function to analyze the structure and distribution of textures, and then determining the size of L neighborhood. Several special fractal sets were adopted and HSL (Hue, Saturation, and Light) color space was chosen. The fractal structure was used to manipulate the texture synthesis in HSL color space where the pattern’s color can be adjusted conveniently. Experiments showed that patterns with different styles and different color characteristics can be more efficiently generated using the new technique.展开更多
Background Three-dimensional terrain models are essential in domains such as video game development and film production.Because surface color is often correlated with terrain geometry,capturing this relationship is cr...Background Three-dimensional terrain models are essential in domains such as video game development and film production.Because surface color is often correlated with terrain geometry,capturing this relationship is critical for generating realistic results.However,most existing methods synthesize either a heightmap or a texture without adequately modeling their inherent correlation.Methods We propose a method that jointly generates terrain heightmaps and textures using a latent diffusion model.First,we train the model in an unsupervised manner to randomly generate paired heightmaps and textures.Then,we perform supervised learning on an external adapter to enable user control via hand-drawn sketches.Results Experiments demonstrate that our approach supports intuitive terrain generation while preserving the correlation between heightmaps and textures.Conclusion Our method outperforms the two-stage and GAN-based baselines by ensuring structural coherence,in which textures naturally align with geometry,successfully accommodating both realistic landscapes and extreme user-defined shapes.展开更多
Organometallic perovskite single crystals have been considered one of the most promising candidates for photodetection applications,owing to their grain-boundary-free structure and improved optoelectronic properties.H...Organometallic perovskite single crystals have been considered one of the most promising candidates for photodetection applications,owing to their grain-boundary-free structure and improved optoelectronic properties.However,several challenges still remain for the application of perovskite single crystals in photodetectors,in particular the thickness and area controls and poor compatibility with substrates.Herein,we report a straightforward fabrication process for realizing large-area(up to 100 cm^(2))and highly textured single-crystal-like MAPbBr3 films by combining inverse-temperature crystallization with a hot-pressing process.Thanks to the following hot-pressing treatment,the obtained perovskites can be effectively integrated onto the FTO substrates without falling,facilitating electrical connections and device integration.The obtained MAPbBr_(3) exhibits a low trap density of 1.4×10^(11) cm^(-3) and a high mobility of 217 cm^(2)·V^(-1)·s^(-1)(with a high mobility-lifetime product of up to 5.4×10^(-4)cm^(2)·V^(-1)).The resulting photodiodes exhibit the self-powered capability and show a maximum responsivity approaching 944 mA·W^(-1),a champion detectivity exceeding 1011 Jones,and a fast photoresponse of 45 ms,together with excellent stability.This study constitutes a demonstration of highly textured,largearea perovskite photodiodes integrated sturdily onto FTO substrates and paves the way for various practical applications,such as optical imaging technology.展开更多
Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexu...Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexural strength of 735 MPa(//c-axis)and high hardness of 7.9 GPa(//c-axis).The strengthening mechanisms were discussed.The sintering and densification process was investigated and crystal orientation and microstructure were studied by electron backscattered diffraction techniques.The synthesis temperature is reduced to 1200?C by using high surface-to-volume ratio Ti2AlC nano flakes.The Lotgering orientation factor of Ti2 AlC and Ti3 AlC2{00 l}planes in the textured top surface reaches 0.74 and 0.49,respectively.This new route may shed light on resolving the difficulties encountered in large scale fabrication of textured MAX phases.展开更多
A simple and effective image inpainting method is proposed in this paper, which is proved to be suitable for different kinds of target regions with shapes from little scraps to large unseemly objects in a wide range o...A simple and effective image inpainting method is proposed in this paper, which is proved to be suitable for different kinds of target regions with shapes from little scraps to large unseemly objects in a wide range of images. It is an important improvement upon the traditional image inpainting techniques. By introducing a new bijeetive-mapping term into the matching cost function, the artificial repetition problem in the final inpainting image is practically solved. In addition, by adopting an inpainting error map, not only the target pixels are refined gradually during the inpainting process but also the overlapped target patches are combined more seamlessly than previous method. Finally, the inpainting time is dramatically decreased by using a new acceleration method in the matching process.展开更多
A series of liquid crystalline multi-block copolymers poly[1.6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segment lengths were synthesized in tetrachloroethane ...A series of liquid crystalline multi-block copolymers poly[1.6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segment lengths were synthesized in tetrachloroethane by solution polycondensation in which hydroxyl terminated PC and acyl chloride terminated PHTH-6 were used. It is found that block copolymers with high molecular weight and well-defined structures were obtained. All the block copolymers exhibit a nematic liquid crystalline texture.展开更多
Described in the paper is the method to fit autoregressive(AR)random field models and Gausslan Markov ran-dom field(GMRF)models for textile textures.Maxi-mum likelihood(ML)estimation schemes and texturesynthesis for t...Described in the paper is the method to fit autoregressive(AR)random field models and Gausslan Markov ran-dom field(GMRF)models for textile textures.Maxi-mum likelihood(ML)estimation schemes and texturesynthesis for these models are presented.Three types oftypical textile textures are tested using the method andsatisfactory results are achieved.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
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
The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids （SO42？/meso‐La0.1Zr0.9Oδ） were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9O...The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids （SO42？/meso‐La0.1Zr0.9Oδ） were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9Oδcomposites, such as the molar ratio of the template to La and Zr metal ions （Nt/m）, molar ratio of ammonia to La and Zr metal ions （Na/m）, hydrothermal temperature （Thydro）, and hy‐drothermal time （thydro）. The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p‐xylene with phenylacetylene was investi‐gated. Various characterization techniques such as N2 physisorption, X‐ray diffraction, NH3 temper‐ature‐programmed desorption, and thermogravimetric analysis were employed to reveal the rela‐tionship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso‐La0.1Zr0.9Oδcomposite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t‐ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42？/meso‐La0.1Zr0.9Oδcatalyst exhibited much superior catalytic activity and coke‐resistant stabil‐ity. Moreover, the developed SO42？/meso‐La0.1Zr0.9Oδcatalyst demonstrated excellent catalytic per‐formance for alkenylation of diverse aromatics with phenylacetylene to their correspondingα‐arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42？/meso‐La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production ofα‐arylstyrenes through clean and atom efficient solid‐acid‐mediated Friedel‐Crafts alkenylation of diverse aromatics with phenylacetylene.展开更多
This paper surveys the state-of-the-art of research in patch-based synthesis. Patch-based methods synthesize output images by copying small regions from exemplar imagery. This line of research originated from an area ...This paper surveys the state-of-the-art of research in patch-based synthesis. Patch-based methods synthesize output images by copying small regions from exemplar imagery. This line of research originated from an area called "texture synthesis", which focused on creating regular or semi-regular textures from small exemplars. However, more recently, much research has focused on synthesis of larger and more diverse imagery, such as photos, photo collections, videos, and light fields. Additionally, recent research has focused on customizing the synthesis process for particular problem domains, such as synthesizing artistic or decorative brushes, synthesis of rich materials, and synthesis for 3D fabrication. This report investigates recent papers that follow these themes, with a particular emphasis on papers published since 2009,when the last survey in this area was published. This survey can serve as a tutorial for readers who are not yet familiar with these topics, as well as provide comparisons between these papers, and highlight some open problems in this area.展开更多
A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simpl...A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simplified and a tangential vector field is created overthe simplified mesh. Then, mapping process searches for the most optimal texture coordinates intexture sample for each triangle, and the textures of neighboring triangles are blended on the mesh.All synthesized texture triangles are compressed to an atlas. Finally, the simplified mesh issubdivided to approach the initial surface. The algorithm has several advantages over formermethods: it synthesizes texture on surface without local parameterization; it does not needpartitioning surface to patches; and it does not need a particular texture sample. The resultsdemonstrate that the new algorithm is applicable to a wide variety of texture samples and anytriangulated surfaces.展开更多
This paper presents a novel method of generating a set of texture tiles from samples, which can be seamlessly tiled into arbitrary size textures in real-time. Compared to existing methods, our approach is simpler and ...This paper presents a novel method of generating a set of texture tiles from samples, which can be seamlessly tiled into arbitrary size textures in real-time. Compared to existing methods, our approach is simpler and more advantageous in eliminating visual seams that may exist in each tile of the existing methods, especially when the samples have elaborate features or distinct colors. Texture tiles generated by our approach can be regarded as single-colored tiles on each orthogonal direction border, which are easier for tiling and more suitable for sentence tiling. Experimental results demonstrate the feasibility and effectiveness of our approach.展开更多
We present a framework for example-based texture synthesis with feature directions aligned to vector fields with 2-way rotational symmetry, also known as orientation fields. Through a simple variational formulation, t...We present a framework for example-based texture synthesis with feature directions aligned to vector fields with 2-way rotational symmetry, also known as orientation fields. Through a simple variational formulation, the framework allows the user to design the orientation field with intuitive controls, by interactively manipulating singularities and field directions. The resulting field is then used to guide a parallel synthesis. Our contribution is twofold： a design tool for orientation fields with a natural boundary condition, and a parallel texture synthesis adapted specifically for using such fields in feature alignment. We demonstrate the advantages of the procedure through examples on planar and curved patches with trivial topology.展开更多
基金Supported by the National Natural Science Foundation of China(60533080)
文摘Texture synthesis has been developed for several years.The traditional technique can generate a larger image from a small image while avoid feeling of repetition or uncontinuity.Some constrained synthesis methods which can synthesize image according to special location demand or other demands have been also proposed in recent years.However,in general,these constrained texture synthesis methods are simple and have few controllable factors to meet user＇s diverse needs.To control multiple-sample texture synthesis more flexibly in various aspects such as synthesis location,proportion and semantic objects,we present an interactive texture synthesis approach based on circular patches and constrained by objects according to a certain ratio.With this approach,source exemplars and the target image are firstly divided into several regions with different characters.Users can click the blocks in the source exemplars and the want-to-be-synthesized region in the target image,and then texture in the target image is synthesized with the corresponding regions in the source exemplars.In the process of texture synthesis,circular patch instead of square patch is used to eliminate the aliasing phenomena.Images are synthesized from multiple sample images with ratio constraint and experiments on images show that our approach can get effective results of ratio-constrained multi-sample synthesis.
文摘A new algorithm is proposed for completing the missing parts caused by the removal of foreground or background elements from an image of natural scenery in a visually plausible way. The major contributions of the proposed algorithm are： （1） for most natural images, there is a strong orientation of texture or color distribution. So a method is introduced to compute the main direction of the texture and complete the image by limiting the search to one direction to carry out image completion quite fast; （2） there exists a synthesis ordering for image completion. The searching order of the patches is defined to ensure the regions with more known information and the structures should be completed before filling in other regions; （3） to improve the visual effect of texture synthesis, an adaptive scheme is presented to determine the size of the template window for capturing the features of various scales. A number of examples are given to demonstrate the effectiveness of the proposed algorithm.
基金This work was mainly supported by National Natural Science Foundation of China(No.61370218)Public Welfare Technology and Industry Project of Zhejiang Provincial Science Technology Department(No.2016C31081,No.LGG18F020013)。
文摘Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images,and is hard to guarantee security.To solve these problems,steganography using reversible texture synthesis based on seeded region growing and LSB is proposed.Secret information is embedded in the process of synthesizing texture image from the existing natural texture.Firstly,we refine the visual effect.Abnormality of synthetic texture cannot be fully prevented if no approach of controlling visual effect is applied in the process of generating synthetic texture.We use seeded region growing algorithm to ensure texture’s similar local appearance.Secondly,the size and capacity of image can be decreased by introducing the information segmentation,because the capacity of the secret information is proportional to the size of the synthetic texture.Thirdly,enhanced security is also a contribution in this research,because our method does not need to transmit parameters for secret information extraction.LSB is used to embed these parameters in the synthetic texture.
基金Supported by the National Natural Science Foundation of China(61103219,60970114)the Program of State Key Lab of Software Engineering(SKLSE 2010-08-24)+3 种基金Fund of Key Laboratory of Information Security Technology(KJ-11-06-2)the Project of Software Science of Hubei Public Security Department,Fundamental Research Funds for the Central Universities(3101045)the National Undergraduate Innovation and Entrepreneurship training program(111048651)the Fund of Huawei Technologies Co.,Ltd(YBCB2011127)
文摘In this paper,a novel concept of multilayer synthesis and a general framework for texture synthesis method are presented.Within this framework,we first decompose the texture into the supposed pattern layer and material layer in the frequency domain by an E-texton extracting algorithm,then manipulate and extend them respectively according to their own personalities,and finally merge the newly synthesized pattern layer and material layer again to generate the final output.Experiment results show that our method not only greatly improves the synthesis quality for those cases that single-layer synthesis cannot handle well but also provides an ability of achieving various special synthesis effects.
基金Project supported by the Natural Science Foundation of Zhejiang Province (No. M603228), Zhejiang Science and Technology Plan Project, and Ningbo Science Foundation for Doctor, China
文摘Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometry and image texture synthesis to solve these problems. We have improved Wei and Levoy (2000)’s texture synthesis algorithm by first using two-dimensional autocorrelation function to analyze the structure and distribution of textures, and then determining the size of L neighborhood. Several special fractal sets were adopted and HSL (Hue, Saturation, and Light) color space was chosen. The fractal structure was used to manipulate the texture synthesis in HSL color space where the pattern’s color can be adjusted conveniently. Experiments showed that patterns with different styles and different color characteristics can be more efficiently generated using the new technique.
文摘Background Three-dimensional terrain models are essential in domains such as video game development and film production.Because surface color is often correlated with terrain geometry,capturing this relationship is critical for generating realistic results.However,most existing methods synthesize either a heightmap or a texture without adequately modeling their inherent correlation.Methods We propose a method that jointly generates terrain heightmaps and textures using a latent diffusion model.First,we train the model in an unsupervised manner to randomly generate paired heightmaps and textures.Then,we perform supervised learning on an external adapter to enable user control via hand-drawn sketches.Results Experiments demonstrate that our approach supports intuitive terrain generation while preserving the correlation between heightmaps and textures.Conclusion Our method outperforms the two-stage and GAN-based baselines by ensuring structural coherence,in which textures naturally align with geometry,successfully accommodating both realistic landscapes and extreme user-defined shapes.
基金the financial support from the University of Sydney International Stipend Scholarship and the University of Sydney Tuition Fee Scholarshipthe support of The University of Sydney Physics Foundation as well as the facilities and technician assistance from the Sydney Microscopy&Microanalysis,Sydney Analytical,and Research Prototype&Foundry at The University of Sydney。
文摘Organometallic perovskite single crystals have been considered one of the most promising candidates for photodetection applications,owing to their grain-boundary-free structure and improved optoelectronic properties.However,several challenges still remain for the application of perovskite single crystals in photodetectors,in particular the thickness and area controls and poor compatibility with substrates.Herein,we report a straightforward fabrication process for realizing large-area(up to 100 cm^(2))and highly textured single-crystal-like MAPbBr3 films by combining inverse-temperature crystallization with a hot-pressing process.Thanks to the following hot-pressing treatment,the obtained perovskites can be effectively integrated onto the FTO substrates without falling,facilitating electrical connections and device integration.The obtained MAPbBr_(3) exhibits a low trap density of 1.4×10^(11) cm^(-3) and a high mobility of 217 cm^(2)·V^(-1)·s^(-1)(with a high mobility-lifetime product of up to 5.4×10^(-4)cm^(2)·V^(-1)).The resulting photodiodes exhibit the self-powered capability and show a maximum responsivity approaching 944 mA·W^(-1),a champion detectivity exceeding 1011 Jones,and a fast photoresponse of 45 ms,together with excellent stability.This study constitutes a demonstration of highly textured,largearea perovskite photodiodes integrated sturdily onto FTO substrates and paves the way for various practical applications,such as optical imaging technology.
基金financially supported by the National Key R&D Program of China(Nos.2017YFB0306201 and 2016YFB0701303).
文摘Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexural strength of 735 MPa(//c-axis)and high hardness of 7.9 GPa(//c-axis).The strengthening mechanisms were discussed.The sintering and densification process was investigated and crystal orientation and microstructure were studied by electron backscattered diffraction techniques.The synthesis temperature is reduced to 1200?C by using high surface-to-volume ratio Ti2AlC nano flakes.The Lotgering orientation factor of Ti2 AlC and Ti3 AlC2{00 l}planes in the textured top surface reaches 0.74 and 0.49,respectively.This new route may shed light on resolving the difficulties encountered in large scale fabrication of textured MAX phases.
基金Supported by the National Natural Science Foundation of China （No. 60403044, No. 60373070） and partly funded by Microsoft Research Asia： Project 2004-Image-01.
文摘A simple and effective image inpainting method is proposed in this paper, which is proved to be suitable for different kinds of target regions with shapes from little scraps to large unseemly objects in a wide range of images. It is an important improvement upon the traditional image inpainting techniques. By introducing a new bijeetive-mapping term into the matching cost function, the artificial repetition problem in the final inpainting image is practically solved. In addition, by adopting an inpainting error map, not only the target pixels are refined gradually during the inpainting process but also the overlapped target patches are combined more seamlessly than previous method. Finally, the inpainting time is dramatically decreased by using a new acceleration method in the matching process.
文摘A series of liquid crystalline multi-block copolymers poly[1.6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segment lengths were synthesized in tetrachloroethane by solution polycondensation in which hydroxyl terminated PC and acyl chloride terminated PHTH-6 were used. It is found that block copolymers with high molecular weight and well-defined structures were obtained. All the block copolymers exhibit a nematic liquid crystalline texture.
文摘Described in the paper is the method to fit autoregressive(AR)random field models and Gausslan Markov ran-dom field(GMRF)models for textile textures.Maxi-mum likelihood(ML)estimation schemes and texturesynthesis for these models are presented.Three types oftypical textile textures are tested using the method andsatisfactory results are achieved.
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.
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.
基金financially supported by the National Natural Science Foundation of China (21276041)the Program for New Century Excellent Talents in University of Ministry of Education (NCET-12-0079)+1 种基金the Natural Science Foundation of Liaoning Province (2015020200)the Fundamental Research Funds for the Central Universities (DUT15LK41)~~
文摘The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids （SO42？/meso‐La0.1Zr0.9Oδ） were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9Oδcomposites, such as the molar ratio of the template to La and Zr metal ions （Nt/m）, molar ratio of ammonia to La and Zr metal ions （Na/m）, hydrothermal temperature （Thydro）, and hy‐drothermal time （thydro）. The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p‐xylene with phenylacetylene was investi‐gated. Various characterization techniques such as N2 physisorption, X‐ray diffraction, NH3 temper‐ature‐programmed desorption, and thermogravimetric analysis were employed to reveal the rela‐tionship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso‐La0.1Zr0.9Oδcomposite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t‐ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42？/meso‐La0.1Zr0.9Oδcatalyst exhibited much superior catalytic activity and coke‐resistant stabil‐ity. Moreover, the developed SO42？/meso‐La0.1Zr0.9Oδcatalyst demonstrated excellent catalytic per‐formance for alkenylation of diverse aromatics with phenylacetylene to their correspondingα‐arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42？/meso‐La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production ofα‐arylstyrenes through clean and atom efficient solid‐acid‐mediated Friedel‐Crafts alkenylation of diverse aromatics with phenylacetylene.
基金the National Science Foundation for support under Grants CCF 0811493 and CCF 0747220the General Financial Grant from the China Postdoctoral Science Foundation(No.2015M580100)
文摘This paper surveys the state-of-the-art of research in patch-based synthesis. Patch-based methods synthesize output images by copying small regions from exemplar imagery. This line of research originated from an area called "texture synthesis", which focused on creating regular or semi-regular textures from small exemplars. However, more recently, much research has focused on synthesis of larger and more diverse imagery, such as photos, photo collections, videos, and light fields. Additionally, recent research has focused on customizing the synthesis process for particular problem domains, such as synthesizing artistic or decorative brushes, synthesis of rich materials, and synthesis for 3D fabrication. This report investigates recent papers that follow these themes, with a particular emphasis on papers published since 2009,when the last survey in this area was published. This survey can serve as a tutorial for readers who are not yet familiar with these topics, as well as provide comparisons between these papers, and highlight some open problems in this area.
文摘A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simplified and a tangential vector field is created overthe simplified mesh. Then, mapping process searches for the most optimal texture coordinates intexture sample for each triangle, and the textures of neighboring triangles are blended on the mesh.All synthesized texture triangles are compressed to an atlas. Finally, the simplified mesh issubdivided to approach the initial surface. The algorithm has several advantages over formermethods: it synthesizes texture on surface without local parameterization; it does not needpartitioning surface to patches; and it does not need a particular texture sample. The resultsdemonstrate that the new algorithm is applicable to a wide variety of texture samples and anytriangulated surfaces.
基金Supported by the National Natural Science Foundation of China(Grant No.60575023)National Research Foundation for the Doctoral Program of Higher Education of China(Grant No.20050359012)+1 种基金the Major Research Project of Natural Science Foundation of Higher Education Institution of Anhui Province(KJ2007A122ZC)Science Research and Development Foundation of Hefei University of Technology of China(Grant No.060504F).
文摘This paper presents a novel method of generating a set of texture tiles from samples, which can be seamlessly tiled into arbitrary size textures in real-time. Compared to existing methods, our approach is simpler and more advantageous in eliminating visual seams that may exist in each tile of the existing methods, especially when the samples have elaborate features or distinct colors. Texture tiles generated by our approach can be regarded as single-colored tiles on each orthogonal direction border, which are easier for tiling and more suitable for sentence tiling. Experimental results demonstrate the feasibility and effectiveness of our approach.
基金Supported in part by the National Science Foundation of USA under Grant Nos. IIS-0953096 and CMMI-1250261the National Natural Science Foundation of China under Grant Nos. 61003145 and 61210007the National High Technology Research and Development 863 Program of China under Grant No. 2012AA011503
文摘We present a framework for example-based texture synthesis with feature directions aligned to vector fields with 2-way rotational symmetry, also known as orientation fields. Through a simple variational formulation, the framework allows the user to design the orientation field with intuitive controls, by interactively manipulating singularities and field directions. The resulting field is then used to guide a parallel synthesis. Our contribution is twofold： a design tool for orientation fields with a natural boundary condition, and a parallel texture synthesis adapted specifically for using such fields in feature alignment. We demonstrate the advantages of the procedure through examples on planar and curved patches with trivial topology.
