#include "sift.h"

/**
    SIFTLOCALMAX  Find local maximizers
   Returns the indexes of the local maximizers of
   the 3-dimensional array F.

    Say, we have a Q-dimensional array F.
   A local maximizer is an element whose value is greater than the
   value of all its neighbors.  The neighbors of an element i1...iQ
   are the subscripts j1...jQ such that iq-1 <= jq <= iq (excluding
   i1...iQ itself).  For example, if Q=1 the neighbors of an element
   are its predecessor and successor in the linear order; if Q=2, its
   neighbors are the elements immediately to its north, south, west,
   est, north-west, north-est, south-west and south-est
   (8-neighborhood).

   Points on the boundary of F are ignored (and never selected as
   local maximizers).

   SEL=SIFTLOCALMAX(F,THRESH) accepts an element as a mazimizer only
   if it is at least THRES greater than all its neighbors.

   SEL=SIFTLOCALMAX(F,THRESH,P) look for neighbors only in the first
   P dimensions of the Q-dimensional array F. This is useful to
   process F in ``slices''.

   REMARK.  Matrices (2-array) with a singleton dimension are
   interpreted as vectors (1-array). So for example SIFTLOCALMAX([0 1
   0]) and SIFTLOCALMAX([0 1 0]') both return 2 as an aswer. However,
   if [0 1 0] is to be interpreted as a 1x2 matrix, then the correct
   answer is the empty set, as all elements are on the boundary.
   Unfortunately MATLAB does not distinguish between vectors and
   2-matrices with a singleton dimension.  To forece the
   interpretation of all matrices as 2-arrays, use
   SIFTLOCALMAX(F,TRESH,2) (but note that in this case the result is
   always empty!).
**/

#define NDIMS 3

F2D* siftlocalmax(F2D* in, float thresh, int intervals, int M, int N)
{  
  int ndims, ptoffset=0, maxIter = 0; 
  int offsets[NDIMS];
  int midx[NDIMS];
  int dims[NDIMS];
  I2D* neighbors ;
  int nneighbors ;
  F2D* out;
    
 /**  
    We pass dogss[o], which has >1 intervals