+/* From phm2image.cpp */
+void phm_to_imagefile (const PHANTOM *phm, ImageFile& im, const int col_start, const int col_count, const int nsample, const int trace);
+int pelm_is_point_inside(PELM *obj, const double x, const double y, const CoordType coord_type);
+
+/* image.cpp */
+void image_filter_response(ImageFile& im, const DomainType domain, double bw, const FilterType filt_type, double filt_param, const int opt_trace);
+int image_display (const ImageFile& im);
+int image_display_scale (const ImageFile& im, const int scale, const double pmin, const double pmax);
+
+/* From reconstr.cpp */
+ImageFile& proj_reconst (ImageFile& im, RAYSUM *rs, const FilterType filt_type, double filt_param, InterpolationType interp_type, int interp_param, const BackprojType backproj_type, int const ir_trace);
+
+/* From bproj.cpp */
+void backproj_init (const RAYSUM *rs, ImageFile& im, const BackprojType bproj_method);
+int backproj_calc (const RAYSUM *rs, ImageFile& im, const double *t, const double view_angle, const int interp_type, const int bproj_method);
+void backproj_term (const RAYSUM *rs, ImageFile& im, const int bproj_method);
+
+void backproj_init_trig (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_trig (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_trig (const RAYSUM *rs, ImageFile& im);
+void backproj_init_table (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_table (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_table (const RAYSUM *rs, ImageFile& im);
+void backproj_init_d (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_d (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_d (const RAYSUM *rs, ImageFile& im);
+void backproj_init_d2 (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_d2 (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_d2 (const RAYSUM *rs, ImageFile& im);
+void backproj_init_id (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_id (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_id (const RAYSUM *rs, ImageFile& im);
+void backproj_init_id2 (const RAYSUM *rs, ImageFile& im);
+int backproj_calc_id2 (const RAYSUM *rs, ImageFile& im, const double *t,
+ const double view_angle, const int interp_type);
+void backproj_term_id2 (const RAYSUM *rs, ImageFile& im);