enum {O_INTERP, O_FILTER, O_FILTER_METHOD, O_ZEROPAD, O_FILTER_PARAM, O_FILTER_GENERATION, O_BACKPROJ, O_PREINTERPOLATION_FACTOR, O_VERBOSE, O_TRACE, O_HELP, O_DEBUG, O_VERSION};
enum {O_INTERP, O_FILTER, O_FILTER_METHOD, O_ZEROPAD, O_FILTER_PARAM, O_FILTER_GENERATION, O_BACKPROJ, O_PREINTERPOLATION_FACTOR, O_VERBOSE, O_TRACE, O_HELP, O_DEBUG, O_VERSION};