Stretch the value of an image.
This function stretches values between min_in and max_in of an image in, to a range that goes from min_out to max_out.
- in Input image, must be have scalar values
- min_in Lower bound of the range in the input. All values smaller than min_in are converted to min_out.
- max_in Upper bound of the range in the input. All values greater than max_in are converted to max_out.
- min_out Low bound of the range in the output.
- max_out Upper bound of the range in the output.
#include <oln/basics1d.hh> #include <oln/convert/stretch.hh> #include <ntg/all.hh> #include <iostream> int main() { oln::image1d<ntg::int_u<17> > im(4); im(0) = 0; im(1) = 2; im(2) = 5000; im(3) = 4000; // print "0 170 511 340" //(values of the *image* are dispatched on the range [0..2^9-1]) std::cout << oln::convert::stretch_balance<ntg::int_u<9> >(im) << std::endl; //print " 0 0 19 16" (19 is the result of 5000 * 2^9 / 2^17) //(values of *int_u<17>* are dispatched on the range [0..2^9-1]) std::cout << apply(oln::convert::stretch<ntg::int_u<9> >(), im) << std::endl; }
This function is useful to stretch images of label:
#include <oln/basics2d.hh> #include <oln/convert/stretch.hh> #include <oln/level/cc.hh> #include <ntg/all.hh> #include <iostream> int main() { oln::image2d<ntg::bin> light = oln::load(IMG_IN "face_se.pbm"); //Extraction of the connected components: unsigned card; oln::image2d<ntg::int_u8> cc = oln::level::frontp_connected_component<ntg::int_u8>(light, oln::neighb_c8(), card); oln::io::save(cc, IMG_OUT "oln_convert_stretch_dark.pgm"); oln::io::save(oln::convert::stretch_balance<ntg::int_u8>(cc), IMG_OUT "oln_convert_stretch_balance.pgm"); }
Definition at line 166 of file stretch.hh.
References oln::abstract::image< Exact >::size().
00173 {
00174 typedef typename
00175 ntg_is_a(DestValue, ntg::non_vectorial)::ensure_type ensure_type;
00176
00177 typename mute<I, DestValue>::ret out(in.size());
00178
00179 //FIXME: I would like to remove the static_cast.
00180 std::vector<ntg_cumul_type(DestValue)>
00181 tab(static_cast<int>(max_in - min_in + 1));
00182 typedef typename std::set<oln_value_type(I)> set_type;
00183 set_type s;
00184 oln_iter_type(I) it(in);
00185
00186 for_all(it)
00187 if (in[it] <= max_in && in[it] >= min_in)
00188 s.insert(in[it]);
00189 if (s.size() == 1)
00190 {
00191 for_all(it)
00192 out[it] = ntg_zero_val(DestValue);
00193 return out;
00194 }
00195 {
00196 unsigned cpt = 0;
00197 for (typename set_type::const_iterator it(s.begin());
00198 it != s.end(); ++it, ++cpt)
00199 tab[*it - min_in] = cpt * (max_out - min_out) / (s.size() - 1);
00200 }
00201 for_all(it)
00202 if (min_in <= in[it])
00203 {
00204 if (in[it] <= max_in)
00205 out[it] = tab[in[it] - min_in] + min_out;
00206 else
00207 out[it] = max_out;
00208 }
00209 else
00210 out[it] = min_out;
00211 return out;
00212 }
