for (j=0;j<col;j++) { 
    for(k=0;k<row;k++) { 
        for(i=0;i<3;i++) { 
            fprintf(fp2,"%d",(int)extract(fp1,offset++,1)); 
            fprintf(fp2," "); 
        } 
        fprintf(fp2," "); 
    } 
    fprintf(fp2,"n"); 
    offset+=2; 
}