std::cout << " --exp Natural exponential of image" << std::endl;
std::cout << " --sqr Square of image" << std::endl;
std::cout << " --sqrt Square root of image" << std::endl;
std::cout << " --exp Natural exponential of image" << std::endl;
std::cout << " --sqr Square of image" << std::endl;
std::cout << " --sqrt Square root of image" << std::endl;