基于自适应阈值的拓扑图像密度单元优化  

Topology image density unit optimization based on adaptive threshold

作　　者：王冲 茅健 郑武 WANG Chong;MAO Jian;ZHENG Wu(School of Mechanical and Automotive Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Huarong Printing Technology Co.,Ltd,Beijing 100089,China)

机构地区：[1]上海工程技术大学机械与汽车工程学院,上海201620 [2]华融普瑞北京科技有限公司,北京100089

出　　处：《智能计算机与应用》2023年第10期73-76,82,共5页Intelligent Computer and Applications

基　　金：北京市科技计划(Z191100008019006)。

摘　　要：拓扑优化变密度法运用固体各项同性材料惩罚模型(SIMP)得到优化的图像中存在大量灰度单元,本文提出基于数字图像处理的自适应阈值空域灰度变换算法,通过数值化提取拓扑结构灰度单元,依据最大类间方差法(OTSU)确定初始阈值,通过histogram函数确定均匀宽度值,依据整体结构灰度值约束条件建立自适应阈值计算公式,得到修正后自适应阈值算子,在满足拓扑约束条件下将图像增强算法应用于拓扑图像。通过典型算例验证了算法可行性,并与最大类间方差法OTSU、动态范围压缩、阶梯量化等算法对比,自适应阈值方法在拓扑约束偏离值仅为0.01%情况下实现灰度单元有效过滤,收敛快速且优化结构清晰。In the density-based method of topology optimization,the solid isotropic material with penalization model(SIMP) is used to obtain a large number of gray units in the optimized structure.In this paper,an adaptive threshold spatial gray scale transformation algorithm based on digital image processing is proposed.In the proposed method,the topological structure gray scale unit is extracted numerically,the initial threshold is determined according to the OTSU maximum inter class variance method,the uniform width bin value is determined through the histogram function,the adaptive threshold calculation formula is established according to the constraint conditions of the overall structure gray scale value,and the modified adaptive threshold operator is obtained.Then image enhancement algorithm is also applied to topological image under the topological constraints.The effectiveness of the method is verified by a typical example.Compared with OTSU Otsu method,dynamic range compression,step quantization and other algorithms,the adaptive threshold method can effectively filter gray units when the deviation value of topology constraint is only 0.01% with fast convergence and clear optimization structure.

关 键 词：拓扑优化 自适应阈值 图像增强 灰度变换 

分 类 号：TH391.41[机械工程—机械制造及自动化]