94 lines
2.5 KiB
Mathematica
94 lines
2.5 KiB
Mathematica
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%--------------------------------------------------------------------------
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% ENSEEIHT - 2SN MM - Traitement des donn<EFBFBD>es audio-visuelles
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% TP6 - Restauration d'images
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% exercice_1_bis : d<EFBFBD>bruitage avec variation totale (niveaux de gris)
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%--------------------------------------------------------------------------
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clear
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close all
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clc
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% Mise en place de la figure pour affichage :
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taille_ecran = get(0,'ScreenSize');
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L = taille_ecran(3);
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H = taille_ecran(4);
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figure('Name','Debruitage par variation totale',...
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'Position',[0.06*L,0.1*H,0.9*L,0.7*H]);
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% Lecture de l'image :
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u0 = double(imread('Images/lena_avec_bruit.bmp'));
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[nb_lignes,nb_colonnes,nb_canaux] = size(u0);
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u_max = max(u0(:));
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% Affichage de l'image :
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subplot(1,2,1)
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imagesc(max(0,min(1,u0/u_max)),[0 1])
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colormap gray
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axis image off
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title('Image bruitee','FontSize',20)
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imwrite(max(0,min(1,u0/u_max)), sprintf('saves/exo1bis_bruit.png'))
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% Affichage de l'image restaur<EFBFBD>e <EFBFBD> l'it<EFBFBD>ration 0 :
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subplot(1,2,2)
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imagesc(max(0,min(1,u0/u_max)),[0 1])
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axis image off
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title('Image restauree (iteration 0)','FontSize',20)
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[fimage,map] = rgb2ind(max(0,min(1,u0/u_max)), 256);
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imwrite(fimage, map, "saves/exo1bis_clean.gif", 'gif', 'Loopcount', inf);
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drawnow nocallbacks
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% Vectorisation de u0 :
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nb_pixels = nb_lignes * nb_colonnes;
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u0 = reshape(u0,[], 1, 3);
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% Param<EFBFBD>tre pour garantir la diff<EFBFBD>rentiabilit<EFBFBD> de la variation totale :
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epsilon = 0.01;
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% Op<EFBFBD>rateur gradient :
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e = ones(nb_pixels,1);
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Dx = spdiags([-e e],[0 nb_lignes],nb_pixels,nb_pixels);
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Dx(end-nb_lignes+1:end,:) = 0;
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Dy = spdiags([-e e],[0 1],nb_pixels,nb_pixels);
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Dy(nb_lignes:nb_lignes:end,:) = 0;
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% Second membre b du syst<EFBFBD>me :
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b = u0;
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% Point fixe :
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lambda = 10; % Poids de la r<EFBFBD>gularisation
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u_k = u0;
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convergence = +Inf;
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iteration = 0;
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while convergence > 1e-3
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% Incr<EFBFBD>mentation du nombre d'it<EFBFBD>rations :
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iteration = iteration + 1;
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% It<EFBFBD>ration (6) :
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u_kp1 = debruitage_bis(b,u_k,lambda,Dx,Dy,epsilon);
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% Test de convergence :
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convergence = norm(u_kp1(:)-u_k(:))/norm(u_k(:));
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% Mise <EFBFBD> jour de l'image courante u_k :
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u_k = u_kp1;
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% Affichage de l'image restaur<EFBFBD>e <EFBFBD> chaque it<EFBFBD>ration :
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subplot(1,2,2)
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image = max(0,min(1,reshape(u_k,[nb_lignes nb_colonnes nb_canaux])/u_max));
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imagesc(image,[0 1])
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colormap gray
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axis image off
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title(['Image restauree (iteration ' num2str(iteration) ')'],'FontSize',20)
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% Write to the GIF File
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[fimage,map] = rgb2ind(image, 256);
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imwrite(fimage, map, "saves/exo1bis_clean.gif", 'gif', 'WriteMode', 'append');
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drawnow nocallbacks
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pause(0.2)
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end
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