图像处理的常见滤波方法，matlab代码

% Author: Bodong Li, College of Information Engineering, Xiangtan University, Xiangtan 411105, China % Time: Created August 28, 2013 % Revised September 11, 2014 clear all; close all; clc; set(0, 'DefaultAxesFontSize', 12); set(0, 'DefaultAxesFontName', 'Arial'); set(0, 'DefaultTextFontSize', 12); set(0, 'DefaultTextFontName', 'Arial'); set(0, 'DefaultFigurePaperPositionMode', 'auto'); % Input the image fname = '04.png'; X = double(imread(fname)); sigmaS = 3; sigmaR = 35.5; w = 20; PSNRs = []; % Add noise randn('seed',1); Y = X + w*randn(size(X)); Y = round(max(0,min(Y,255))); fname = [fname(1:end-4),'_G',int2str(w),'.png']; imwrite(Y/255,fname); %% a = (X-Y).^2; MSE = mean(a(:)); PSNR = 10*log10(255*255/MSE); fprintf('Noisy psnr = %0.2f\n', PSNR); PSNRs = [PSNRs,PSNR]; % Denoise the noisy image using mean-filtering MN = fn_mean(Y,sigmaS); imwrite(MN/255,[fname(1:end-4),'_mean_',int2str(4*sigmaS+1),'.png']); %% a = (X-MN).^2; MSE = mean(a(:)); PSNR = 10*log10(255*255/MSE); fprintf('Mean psnr = %0.2f\n', PSNR); PSNRs = [PSNRs,PSNR]; % Denoise the noisy image using median-filtering ME = fn_median(Y,sigmaS); imwrite(ME/255,[fname(1:end-4),'_median_',int2str(4*sigmaS+1),'.png']); %% a = (X-ME).^2; MSE = mean(a(:)); PSNR = 10*log10(255*255/MSE); fprintf('Median psnr = %0.2f\n', PSNR); PSNRs = [PSNRs,PSNR]; % Denoise the noisy image using gaussian-filtering GS = fn_gaussian(Y,sigmaS); imwrite(GS/255,[fname(1:end-4),'_gaussian_',int2str(4*sigmaS+1),'.png']); %% a = (X-GS).^2; MSE = mean(a(:)); PSNR = 10*log10(255*255/MSE); fprintf('Gauss psnr = %0.2f\n', PSNR); PSNRs = [PSNRs,PSNR]; % Denoise the noisy image using bilateral-filtering BL = fn_bilateral(Y,sigmaS,sigmaR); imwrite(BL/255,[fname(1:end-4),'_bilateral_',int2str(4*sigmaS+1),'_',sprintf('%0.1f',sigmaR),'.png']); %% a = (X-BL).^2; MSE = mean(a(:)); PSNR = 10*log10(255*255/MSE); fprintf('Bilate psnr = %0.2f\n', PSNR); PSNRs = [PSNRs,PSNR]; figure; imshow(X,[]); title('original'); figure; imshow(Y,[]); title(['noisy psnr = ',num2str(PSNRs(1))]); figure; imshow(MN,[]); title(['mean psnr = ',num2str(PSNRs(2))]); figure; imshow(ME,[]); title(['median psnr = ',num2str(PSNRs(3))]); figure; imshow(GS,[]); title(['gaussian psnr = ',num2str(PSNRs(4))]); figure; imshow(BL,[]); title(['bilateral psnr = ',num2str(PSNRs(5))]);