基于非线性渐变式颜色映射的LIC改进算法  

Improved LIC algorithm based on nonlinear gradual-changing color mapping

作　　者：高茂庭[1] 董红周 周凡[1] Gao Maoting;Dong Hongzhou;Zhou Fan(College of Information Engineering,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]上海海事大学信息工程学院

出　　处：《计算机应用研究》2019年第9期2834-2839,共6页Application Research of Computers

基　　金：国家自然科学基金资助项目(41701523)

摘　　要：线积分卷积(LIC)算法展现的纹理反映了整个矢量场的方向结构,却不能展现矢量场的强度大小。针对此问题提出基于非线性渐变式颜色映射的LIC改进算法,将矢量场强度与白噪声结合作为LIC的输入纹理,运用Fast LIC思想并划分纹理区域同步执行LIC运算来提高算法效率;再将矢量场强度作非线性变换,根据渐变式颜色映射方案使用Open CV处理引擎并行实现矢量场强度的颜色映射;最后由LIC得到的灰度纹理和颜色映射结果确定合成系数并构造累计函数增强两者结果,再进行线性合成运算得到最终可视化效果。在对全球海洋流场和风场两种典型的矢量场进行可视化以及与其他算法对比实验表明,改进算法得到的可视化效果纹理清晰,较好地展示出矢量场的方向和强度,能够更准确地反映矢量场的全方位信息和局部变化情况。The texture revealed by LIC reflects the directional structure of the whole vector field,but cannot show the field intensity.In order to solve this problem,this paper proposed an improved LIC algorithm based on nonlinear gradual-changing co- lor mapping.Firstly,the intensity of vector field combined with white noise to form the input texture of improved LIC,which used the idea of FastLIC and divided the texture into several regions for synchronous execution of LIC,to improve the efficiency of LIC.Secondly,the improved LIC did a non-linear transformation on the intensity of vector field,and used the processing engine,OpenCV,to implement the color mapping of the vector field intensity according to the gradual-changing color-mapping scheme.Finally,the results of gray texture obtained by LIC and color mapping determined the synthetic coefficient,constructing a cumulative function enhanced the two results,and adopting the way of linear synthesis obtained the final visualization.Simulation results show that when applied to the global ocean flow field and wind field,the proposed algorithm generates a clear visualization displays the direction and intensity of vector field better,and reflects the global information and local changes of the vector field better,when compared with other algorithms.

关 键 词：线积分卷积 矢量场 场强 可视化 累计函数 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]