// nearest neighbor search, using a given coherence set
void nn_search(Img *destim, int di, int dj, const Kcoherence<K> &kset,
int offx, int offy,
unsigned &bestdiff,unsigned &bestidx)
{
for(int k=0;k<kset.n;k++) {
int i,j;
srcim->idx_to_ij(kset[k],i,j);
i = srcim->wrapw(i+offx);
j = srcim->wraph(j+offy);
if(!srcwrap && (i<Nsize || i>=srcim->w-Nsize))
continue;
if(!srcwrap && (j<Nsize || j>=srcim->h-Nsize))
continue;
unsigned diff = neighbor_diff(destim, srcim, di,dj, i,j, Nsize);
if(diff < bestdiff) {
bestdiff = diff;
bestidx = srcim->ij_to_idx(i,j);
}
}
}
