We present a method to represent multi-resolution vector graphics such as road networks or railway networks in virtual environment. These vector data can be interactively edited and the landscape and be explored in re...We present a method to represent multi-resolution vector graphics such as road networks or railway networks in virtual environment. These vector data can be interactively edited and the landscape and be explored in real time at any altitude from flight view to car view. We design a context-focused vector description of linear can areal features, with associated customized definition painter to specify their appearance （color and material） and their display mode （detailed mode or simplified mode）. There are some special problems in drawing vector graphics in virtual environment. Floating-point round-off error appear when we use a low view point to observe the scene, and it leads to scene jittering. Drawing 3D wide lines turns into a problem on 3D terrain. We design a view-based self-adaptive interpolation algorithm and an offset line generating algorithm to solve it. Our results show high performance with good visual quality.展开更多
Because the existing vector data watermarking algorithm is insufficiently robust for compression and cropping,and has no sufficient control on map deformation,a new watermarking algorithm was proposed in this paper.It...Because the existing vector data watermarking algorithm is insufficiently robust for compression and cropping,and has no sufficient control on map deformation,a new watermarking algorithm was proposed in this paper.Its main features are：① it selected feature points and non-feature points from the sequence of Douglas,and then embedded watermarking points by wavelet transform,which is based on layer segmentation;② it enhanced the map deformation control design.Furthermore,it increased the map graphic deformation control design.The algorithm was applied to experimental data,and the test results showed that the algorithm had good robustness on graphics geometric transformation,the addition,deletion and cropping of points in graph layers.Also,the graph distortion had been well controlled.展开更多
Recent development and recognition methods of raster to vector conversion for engineering drawings are presented. The advantages and disadvantages of all existing models are analyzed. Some research challenges and futu...Recent development and recognition methods of raster to vector conversion for engineering drawings are presented. The advantages and disadvantages of all existing models are analyzed. Some research challenges and future directions are discussed.展开更多
传统的三维图形处理器通过裁剪操作获取三角形的可见区域。然而,裁剪操作的延迟长且硬件开销高,大量的裁剪操作会降低图形处理器的性能。本文设计了一款基于OpenGL ES 2.0标准的三维图形处理器芯片,采用了统一渲染架构。该图形处理器采...传统的三维图形处理器通过裁剪操作获取三角形的可见区域。然而,裁剪操作的延迟长且硬件开销高,大量的裁剪操作会降低图形处理器的性能。本文设计了一款基于OpenGL ES 2.0标准的三维图形处理器芯片,采用了统一渲染架构。该图形处理器采用高效的无裁剪图形流水线结构,消除了裁剪所带来的硬件开销和性能损耗。此外,本文为该图形处理器设计了一个符合IEEE-754标准的三维向量内积(DP3)计算单元,用于固定功能流水线,以提高图形处理器的性能,并消除图形渲染过程中浮点乘加操作的误差,增强了图形处理器的图形渲染鲁棒性。该三维图形处理器每秒能够处理500 M个顶点和8 G个纹素,功耗为1000 mW,采用了28 nm工艺,面积为7.92 mm^(2)。实现结果表明,与之前的工作相比,本文设计的图形处理器的性能-功耗比提高了27.8%。展开更多
The web of meso-scale meteorological observational station based on WebGIS realized by SVG technology was briefly introduced.Through grasping and applying SVG technology,the high-density automatic observational statio...The web of meso-scale meteorological observational station based on WebGIS realized by SVG technology was briefly introduced.Through grasping and applying SVG technology,the high-density automatic observational station in Anhui Province was developed.The web of meso-scale meteorological observational stations constructed by SVG technique can display the network graphics of weather data and intuitionistic vector graphics interface.展开更多
基金Supported by National Basic Research Program of China (973 Program,No.2010CB328002)National Natural Science Foundation of China (Nos.61232014,61121002,61173080)National Key Technology Research and Development Program of China (No.2013BAK03B07)
文摘We present a method to represent multi-resolution vector graphics such as road networks or railway networks in virtual environment. These vector data can be interactively edited and the landscape and be explored in real time at any altitude from flight view to car view. We design a context-focused vector description of linear can areal features, with associated customized definition painter to specify their appearance （color and material） and their display mode （detailed mode or simplified mode）. There are some special problems in drawing vector graphics in virtual environment. Floating-point round-off error appear when we use a low view point to observe the scene, and it leads to scene jittering. Drawing 3D wide lines turns into a problem on 3D terrain. We design a view-based self-adaptive interpolation algorithm and an offset line generating algorithm to solve it. Our results show high performance with good visual quality.
基金Supported by the National Natural Science Foundation of China (40401038)
文摘Because the existing vector data watermarking algorithm is insufficiently robust for compression and cropping,and has no sufficient control on map deformation,a new watermarking algorithm was proposed in this paper.Its main features are：① it selected feature points and non-feature points from the sequence of Douglas,and then embedded watermarking points by wavelet transform,which is based on layer segmentation;② it enhanced the map deformation control design.Furthermore,it increased the map graphic deformation control design.The algorithm was applied to experimental data,and the test results showed that the algorithm had good robustness on graphics geometric transformation,the addition,deletion and cropping of points in graph layers.Also,the graph distortion had been well controlled.
文摘Recent development and recognition methods of raster to vector conversion for engineering drawings are presented. The advantages and disadvantages of all existing models are analyzed. Some research challenges and future directions are discussed.
基金Supported by Anhui Meteorological Observatory Projects " Integration Design of Station Meteorological Observation Operation"
文摘The web of meso-scale meteorological observational station based on WebGIS realized by SVG technology was briefly introduced.Through grasping and applying SVG technology,the high-density automatic observational station in Anhui Province was developed.The web of meso-scale meteorological observational stations constructed by SVG technique can display the network graphics of weather data and intuitionistic vector graphics interface.
