Imregion *roi_alloc(int lx, int ly, int ux, int uy) Imregion *roi_copy(Imregion * roi) void roi_update(Imregion * roi, Imregion * copy) int roi_inregion(Imregion * region, int x, int y) Imregion *roi_inter(Imregion * r1, Imregion * r2) void roi_fill(Imregion * roi, int lx, int ly, int ux, int uy)
With obvious meanings apart from roi_inter which performs region intersection.