Mat filtroLaplaciano(Mat img){

    float **Masc = (float **) malloc (3 *sizeof (float*));
    for(int i=0; i<3; i++){
        Masc[i] = (float *) malloc (3 *sizeof (float));
    }

    Masc[0][0] = 0;     Masc[0][1] = -1;    Masc[0][2] = 0;
    Masc[1][0] = -1;    Masc[1][1] = 4;     Masc[1][2] = -1;
    Masc[2][0] = 0;     Masc[2][1] = -1;    Masc[2][2] = 0;

    return convoluirGenerica(img, Masc, 3, 3);
}