去噪和非线性效应中滤波方法的选择研究

针对去噪和非线性效应中滤波的特点,分析了去噪和非线性效应的基本原理,给出了矩形滤波、汉宁滤波和门限滤波的方法及其优缺点,比较了这三种滤波方法对傅里叶变换轮廓术(FTP)测量准确度的影响.计算机仿真表明:对于线性系统中的去噪处理,选用门限滤波效果最佳;对于非线性效应中滤波,选用矩形滤波与汉宁滤波效果较佳.实验中主要表现为非线性效应.结果表明:用矩形滤波,物体面形恢复的最好,用门限滤波,物体面形恢复的最差.计算机仿真和实验结果都表明:矩形滤波与汉宁滤波相比较,用矩形滤波效果更佳.

Study on Choice of Method of Filter in De-noising and Effect of Nonlinear

For the characteristics in de-noising and the effect of nonlinear, basic theorems in de-noising and the effect of nonlinear are analyzed, Three methods (the filter of rectangle window, hanning window and threshold restriction) of their advantages and disadvantages are given. The effect of measuring precision for fourier transform profilometry (FTP) among three different methods of filter are compared. Computer simulations indicate that threshold restriction is the best method for de-noising in linear, but the methods of rectangle window and hanning window are better than that of threshold restriction in nonlinear. The effect of nonlinear is for the most part in experiments, the result shows that the methods of rectangle window is the best while that of threshold restriction is the worst to regain the shape of object. Compared the rectangle window with the hanning window in filter of Computer simulations and experiments, the effect of rectangle window is better than the latter.