% Calcul d'une mosaique d'image à partir de 2 images : I1 et I2
% connaissant l'homographie H entre les 2.
% L'image resultat est stockee dans Res.
% On choisit de projeter I2 dans I1 pour construire la mosaique.
% Attention !!!
% On suppose un axe de rotation parallèle aux colonnes.
% C'est la raison pour laquelle on inverse les lignes et les colonnes
% dans la reconstruction de la mosaique.

function [Imos] = mosaiqueNbis(TailleFenetre, NbPoints, k, seuil, imref, varargin)
    homos = cell(1, length(varargin));
    homos(1) = {eye(3)};
    for i = 1:length(varargin) - 1
        Im1 = im2double(varargin{i});
        Im2 = im2double(varargin{i+1});

        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        % Detection des points d'interet avec Harris %
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        Im1_gray = rgb2gray(Im1);
        Im2_gray = rgb2gray(Im2);
        XY_1 = harris(Im1_gray, TailleFenetre, NbPoints, k);
        XY_2 = harris(Im2_gray, TailleFenetre, NbPoints, k);

        % affichage temporaire
        figure;
        affichage_POI(Im1,XY_1,'POI Image 1',1,2,1);
        affichage_POI(Im2,XY_2,'POI Image 2',1,2,2);

        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        % Appariement des points d'interet %
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        [XY_C1, XY_C2] = apparier_POI(Im1_gray, XY_1, Im2_gray, XY_2, TailleFenetre, seuil);

        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        % Estimation (et verification) de l'homographie %
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        % https://github.com/hero9968/Multiple-View-Geometry-in-Computer-Vision/blob/master/vgg_examples/ransacfithomography_vgg.m
        s = 4;
        t = 0.999;
        fitFuncHomo = @(XY) homographie(XY(:, 1:2), XY(:, 3:4));
        disFuncHomo = @(H, XY) distance_homographie(XY(:, 1:2), XY(:, 3:4), H);
        [H, idx] = ransac([XY_C1, XY_C2], fitFuncHomo, disFuncHomo, s, t);
        % XY = [XY_C1, XY_C2];
        % H = homographie(XY(:, 1:2), XY(:, 3:4));
        homos(i + 1) = {H};

        figure('Name', 'Appariement des points d''interet RANSAC');
        affichage_appariement(Im1, XY_C1(idx, 1), XY_C1(idx, 2), 'Points d''interet Image 1', 1, 2, 1);
        affichage_appariement(Im2, XY_C2(idx, 1), XY_C2(idx, 2), 'Points d''interet correspondants Image 2', 1, 2, 2);
        
    end

    homos_to_ref = cell(1, length(varargin));
    homos_to_ref(imref) = {eye(3)};
    homos_tmp = eye(3);
    for i = imref-1:-1:1
        homos_tmp = homos_tmp / homos{i + 1};
        homos_to_ref(i) = {homos_tmp};
    end
    homos_tmp = eye(3);
    for i = imref+1:length(varargin)
        homos_tmp = homos_tmp * homos{i};
        homos_to_ref(i) = {homos_tmp};
    end
    
    %%%%%%%%%%%%%%%%%%%%%%
    % Collage des images %
    %%%%%%%%%%%%%%%%%%%%%%
    Imos = mosaiqueter2(homos_to_ref, varargin);
    imwrite(Imos, "test.png");