https://svn.lrde.epita.fr/svn/oln/trunk/milena Index: ChangeLog from Thierry Geraud <thierry.geraud@lrde.epita.fr> Make room for some non-generic routines. * mln/world: New directory. * mln/world/binary_2d: New directory. * mln/world/binary_2d/subsample.hh: New. subsample.hh | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) Index: mln/world/binary_2d/subsample.hh --- mln/world/binary_2d/subsample.hh (revision 0) +++ mln/world/binary_2d/subsample.hh (revision 0) @@ -0,0 +1,28 @@ + +// FIXME: Complete this file. + + +template <typename I> +image2d<int_u8> subsample(const image2d<bool>& input, unsigned n) +{ + typedef bool* ptr; + ptr p = new ptr(n); + const unsigned nrows = input.nrows() / n; + + dpoint2d dp_row(1, 0); + const unsigned delta_row = input.delta_index(dp_row); + + for (unsigned row = 0; row < nrows; ++row) + { + unsigned count = 0; + ptr[0] = & input(point2d(n * row, 0)); + for (unsigned i = 1; i < n; ++i) + ptr[i] = ptr[i-1] + delta_row; + for (unsigned col = 0; col < ncols; ++col) + { + for (unsigned i = 0; i < n; ++i) + count += *(ptr[i]++); + output(point2d(row, col)) = count * 255 / n / n; + } + } +}