/// read a directory and return a vector of vtkImageData
bool readDirectory( const std::string i_pathname, // in information names
std::vector<std::string> i_attr, // in information attributes names
std::vector<std::map <std::string , std::string> > &i_imgAttr, // out information attributes names-values
std::vector<vtkImageData *> &i_imgs); // out information vtkImageData
/// read a directory and return a vector of vtkImageData
bool readDirectory( const std::string i_pathname, // in information names
std::vector<std::string> i_attr, // in information attributes names
std::vector<std::map <std::string , std::string> > &i_imgAttr, // out information attributes names-values
std::vector<vtkImageData *> &i_imgs); // out information vtkImageData