TV去噪主页:http://visl.technion.ac.il/~gilboa/PDE-filt/tv_denoising.html
可以下载MATLAB代码。
function J=tv(I,iter,dt,ep,lam,I0,C) %% Private function: tv (by Guy Gilboa). %% Total Variation denoising. %% Example: J=tv(I,iter,dt,ep,lam,I0) %% Input: I - image (double array gray level 1-256), %% iter - num of iterations, %% dt - time step [0.2], %% ep - epsilon (of gradient regularization) [1], %% lam - fidelity term lambda [0], %% I0 - input (noisy) image [I0=I] %% (default values are in []) %% Output: evolved image if ~exist(‘ep‘) ep=1; end if ~exist(‘dt‘) dt=ep/5; % dt below the CFL bound end if ~exist(‘lam‘) lam=0; end if ~exist(‘I0‘) I0=I; end if ~exist(‘C‘) C=0; end [ny,nx]=size(I); ep2=ep^2; for i=1:iter, %% do iterations % estimate derivatives I_x = (I(:,[2:nx nx])-I(:,[1 1:nx-1]))/2; I_y = (I([2:ny ny],:)-I([1 1:ny-1],:))/2; I_xx = I(:,[2:nx nx])+I(:,[1 1:nx-1])-2*I; I_yy = I([2:ny ny],:)+I([1 1:ny-1],:)-2*I; Dp = I([2:ny ny],[2:nx nx])+I([1 1:ny-1],[1 1:nx-1]); Dm = I([1 1:ny-1],[2:nx nx])+I([2:ny ny],[1 1:nx-1]); I_xy = (Dp-Dm)/4; % compute flow Num = I_xx.*(ep2+I_y.^2)-2*I_x.*I_y.*I_xy+I_yy.*(ep2+I_x.^2); Den = (ep2+I_x.^2+I_y.^2).^(3/2); I_t = Num./Den + lam.*(I0-I+C); I=I+dt*I_t; %% evolve image by dt end % for i %% return image %J=I*Imean/mean(mean(I)); % normalize to original mean J=I;
另外有博主谢了C++的代码:经典的变分法图像去噪的C++实现 ,不过个人感觉写的不太简洁。稍稍修改了一下,新版代码出炉:
//TV去噪函数 Mat TVDenoising(Mat img, int iter) { int ep = 1; int nx=img.cols; int ny = img.rows; double dt = 0.25f; double lam = 0.0; int ep2 = ep*ep; double** image = newDoubleMatrix(nx, ny); double** image0 = newDoubleMatrix(nx, ny); for(int i=0;i<ny;i++){ uchar* p=img.ptr<uchar>(i); for(int j=0;j<nx;j++){ image0[i][j]=image[i][j]=(double)p[j]; } } //double** image_x = newDoubleMatrix(nx, ny); //I_x = ( I(:,[2:nx nx]) - I(:,[1 1:nx-1]))/2; //double** image_xx = newDoubleMatrix(nx, ny); //I_xx = I(:,[2:nx nx])+I(:,[1 1:nx-1])-2*I; //double** image_y = newDoubleMatrix(nx, ny); //I_y = (I([2:ny ny],:)-I([1 1:ny-1],:))/2; //double** image_yy = newDoubleMatrix(nx, ny); //I_yy = I([2:ny ny],:)+I([1 1:ny-1],:)-2*I; //double** image_dp = newDoubleMatrix(nx, ny); //Dp = I([2:ny ny],[2:nx nx])+I([1 1:ny-1],[1 1:nx-1 //double** image_dm = newDoubleMatrix(nx, ny); //Dm = I([1 1:ny-1],[2:nx nx])+I([2:ny ny],[1 1:nx-1]); //double** image_xy = newDoubleMatrix(nx, ny); //I_xy = (Dp-Dm)/4; //double** image_num = newDoubleMatrix(nx, ny); //Num = I_xx.*(ep2+I_y.^2)-2*I_x.*I_y.*I_xy+I_yy.*(ep2+I_x.^2); //double** image_den = newDoubleMatrix(nx, ny); //Den = (ep2+I_x.^2+I_y.^2).^(3/2); ////////////////////////////////////////////////////////////////////////// //对image进行迭代iter次 //iter = 80; for (int t = 1; t <= iter; t++){ //for (int i = 0; i < ny; i++){ // for (int j = 0; j < nx; j++){ // //I_x = (I(:,[2:nx nx])-I(:,[1 1:nx-1]))/2; // //I_y = (I([2:ny ny],:)-I([1 1:ny-1],:))/2; // //I_xx = I(:,[2:nx nx])+I(:,[1 1:nx-1])-2*I; // //I_yy = I([2:ny ny],:)+I([1 1:ny-1],:)-2*I; // //Dp = I([2:ny ny],[2:nx nx])+I([1 1:ny-1],[1 1:nx-1]); // //Dm = I([1 1:ny-1],[2:nx nx])+I([2:ny ny],[1 1:nx-1]); // //I_xy = (Dp-Dm)/4; // int tmp_i1=(i+1)<ny ? (i+1) :(ny-1); // int tmp_j1=(j+1)<nx ? (j+1): (nx-1); // int tmp_i2=(i-1) > -1 ? (i-1) : 0; // int tmp_j2=(j-1) > -1 ? (j-1) : 0; // image_x[i][j] = (image[i][tmp_j1] - image[i][tmp_j2])/2; // image_y[i][j]= (image[tmp_i1][j]-image[tmp_i2][j])/2; // image_xx[i][j] = image[i][tmp_j1] + image[i][tmp_j2]- image[i][j]*2; // image_yy[i][j]= image[tmp_i1][j]+image[tmp_i2][j] - image[i][j]*2; // image_dp[i][j]=image[tmp_i1][tmp_j1]+image[tmp_i2][tmp_j2]; // image_dm[i][j]=image[tmp_i2][tmp_j1]+image[tmp_i1][tmp_j2]; // image_xy[i][j] = (image_dp[i][j] - image_dm[i][j])/4; // image_num[i][j] = image_xx[i][j]*(image_y[i][j]*image_y[i][j] + ep2) // - 2*image_x[i][j]*image_y[i][j]*image_xy[i][j] + image_yy[i][j]*(image_x[i][j]*image_x[i][j] + ep2); // image_den[i][j] = pow((image_x[i][j]*image_x[i][j] + image_y[i][j]*image_y[i][j] + ep2), 1.5); // image[i][j] += dt*(image_num[i][j]/image_den[i][j] + lam*(image0[i][j] - image[i][j])); // } //} for (int i = 0; i < ny; i++){ for (int j = 0; j < nx; j++){ int tmp_i1=(i+1)<ny ? (i+1) :(ny-1); int tmp_j1=(j+1)<nx ? (j+1): (nx-1); int tmp_i2=(i-1) > -1 ? (i-1) : 0; int tmp_j2=(j-1) > -1 ? (j-1) : 0; double tmp_x = (image[i][tmp_j1] - image[i][tmp_j2])/2; //I_x = (I(:,[2:nx nx])-I(:,[1 1:nx-1]))/2; double tmp_y= (image[tmp_i1][j]-image[tmp_i2][j])/2; //I_y = (I([2:ny ny],:)-I([1 1:ny-1],:))/2; double tmp_xx = image[i][tmp_j1] + image[i][tmp_j2]- image[i][j]*2; //I_xx = I(:,[2:nx nx])+I(:,[1 1:nx-1])-2*I; double tmp_yy= image[tmp_i1][j]+image[tmp_i2][j] - image[i][j]*2; //I_yy = I([2:ny ny],:)+I([1 1:ny-1],:)-2*I; double tmp_dp=image[tmp_i1][tmp_j1]+image[tmp_i2][tmp_j2]; //Dp = I([2:ny ny],[2:nx nx])+I([1 1:ny-1],[1 1:nx-1]); double tmp_dm=image[tmp_i2][tmp_j1]+image[tmp_i1][tmp_j2]; //Dm = I([1 1:ny-1],[2:nx nx])+I([2:ny ny],[1 1:nx-1]); double tmp_xy = (tmp_dp - tmp_dm)/4; //I_xy = (Dp-Dm)/4; double tmp_num = tmp_xx*(tmp_y*tmp_y + ep2) - 2*tmp_x*tmp_y*tmp_xy +tmp_yy*(tmp_x*tmp_x + ep2); //Num = I_xx.*(ep2+I_y.^2)-2*I_x.*I_y.*I_xy+I_yy.*(ep2+I_x.^2); double tmp_den= pow((tmp_x*tmp_x + tmp_y*tmp_y + ep2), 1.5); //Den = (ep2+I_x.^2+I_y.^2).^(3/2); image[i][j] += dt*(tmp_num/tmp_den+ lam*(image0[i][j] - image[i][j])); } } } Mat new_img; img.copyTo(new_img); for(int i=0;i<img.rows;i++){ uchar* p=img.ptr<uchar>(i); uchar* np=new_img.ptr<uchar>(i); for(int j=0;j<img.cols;j++){ int tmp=(int)image[i][j]; tmp=max(0,min(tmp,255)); np[j]=(uchar)(tmp); } } ////////////////////////////////////////////////////////////////////////// //删除内存 //deleteDoubleMatrix(image_x, nx, ny); //deleteDoubleMatrix(image_y, nx, ny); //deleteDoubleMatrix(image_xx, nx, ny); //deleteDoubleMatrix(image_yy, nx, ny); //deleteDoubleMatrix(image_dp, nx, ny); //deleteDoubleMatrix(image_dm, nx, ny); //deleteDoubleMatrix(image_xy, nx, ny); //deleteDoubleMatrix(image_num, nx, ny); //deleteDoubleMatrix(image_den, nx, ny); deleteDoubleMatrix(image0, nx, ny); deleteDoubleMatrix(image, nx, ny); //imshow("Image",img); //imshow("Denosing",new_img); return new_img; }
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