Laborator 5 clase de echivalenta.

#include <iostream>
#include <opencv2/opencv.hpp>
#include <vector>
#include <random>

using namespace cv;
using namespace std;

int main() {
    Mat_<uchar> image;
    image = imread( "/home/visoft/temp/OpenCVApplication-VS2019_OCV451_basic/Images/letters.bmp", IMREAD_GRAYSCALE);
    imshow("Display Image", image);
    Mat_<int> labels(image.rows, image.cols);
    labels = 0;
    int crt_label = 0;
    int d_col[] = {0,  -1, -1, -1};
    int d_row[] = {-1, -1,  0,  1};

    vector<vector<int>> edges;
    edges.push_back({});

    for(int j=0; j < image.cols; j++){ // pe orizontala (coloane)
        for(int i=0; i < image.rows; i++){ // pe verticala (randul)
            if ((image(i, j) == 0) && (labels(i, j) == 0)){
                vector<int> L;
                for (int v=0;v<4;v++) {
                    int vec_i = i + d_row[v];
                    int vec_j = j + d_col[v];
                    if ((0 <= vec_i) && (vec_i < image.rows) && (0 <= vec_j) && (vec_j < image.cols)) {
                        if (labels(vec_i, vec_j) > 0) {
                            L.push_back(labels(vec_i, vec_j));
                        }
                    }// end if in imagine
                }// end for vecini
                if (L.size() == 0){
                    // NU am gasit vecini
                    crt_label++;
                    labels(i, j) = crt_label;
                    edges.push_back({});
                }else{
                    int x = L[0];
                    for (int v = 0; v < L.size(); v++){
                        x = min(x, L[v]);
                    }
                    labels(i, j) = x;
                    for (int v = 0 ; v < L.size(); v++){
                        int y = L[v];
                        if (y != x){
                            edges[x].push_back(y);
                            edges[y].push_back(x);
                        }
                    }
                };
            } //end if pixel obiect
        }
    }

    int newlabel = 0;
    vector<int> newlabels(crt_label + 1);
    for (int i = 1; i < crt_label; i++){
        if (newlabels[i] == 0){
            newlabel++;
            queue<int> Q;
            newlabels[i] = newlabel;
            Q.push(i);
            while(Q.size() > 0){
                int x;
                x = Q.front(); Q.pop();
                for (int v=0; v < edges[x].size();v++){
                    int y = edges[x][v];
                    if (newlabels[y] == 0){
                        newlabels[y] = newlabel;
                        Q.push(y);
                    }
                }
            }
        }
    }


    Mat_<Vec3b> lab_rgb(image.rows, image.cols);

    int NR_MAX_CULORI = 500;
    default_random_engine gen;
    uniform_int_distribution<int> d(0,255);

    vector<Vec3b> paleta(NR_MAX_CULORI);
    paleta[0] = Vec3b(255, 255, 255);
    for (int v = 1; v < NR_MAX_CULORI; v++){
        paleta[v][0] =d(gen);
        paleta[v][1] =d(gen);
        paleta[v][2] =d(gen);
    }


    for (int i=0;i<image.rows;i++)
        for (int j=0;j<image.cols;j++){
            int index_paleta = labels(i,j) % NR_MAX_CULORI;
            int clasa_echival = newlabels[index_paleta];
            lab_rgb(i,j) = paleta[clasa_echival];
        }
    imshow("etichete", lab_rgb);

    waitKey(0);
    return 0;
}