Generic Manipulation of mixed image types

This routine is used to apply a function to images of type ptr_v and float_v.

Imrect *im_pf_apply(Imrect * im1, double (*func) (), void *data)

Imrect *im_pp_apply(Imrect * im1, void *(*func) (), void *data)

Imrect *im_ppf_combine(Imrect * im1, Imrect * im2, double (*func) (),
                       void *data)

Imrect *im_ppp_combine(Imrect * im1, Imrect * im2, void *(*func) (), void *data)

void    im_ptr_apply(Imrect * im, void (*func) (), void *data)