@ -151,6 +151,7 @@ namespace cv
}
/****************************************************************************************\
* Common declarations *
\ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@ -187,6 +188,8 @@ static inline cv::Size cvGetMatSize( const CvMat* mat )
return cv : : Size ( mat - > cols , mat - > rows ) ;
}
/****************************************************************************************\
* Structures and macros for integration with IPP *
\ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@ -245,4 +248,111 @@ typedef enum CvStatus
}
CvStatus ;
/****************************************************************************************\
* Auxiliary algorithms *
\ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
namespace cv
{
// This function splits the input sequence or set into one or more equivalence classes and
// returns the vector of labels - 0-based class indexes for each element.
// predicate(a,b) returns true if the two sequence elements certainly belong to the same class.
//
// The algorithm is described in "Introduction to Algorithms"
// by Cormen, Leiserson and Rivest, the chapter "Data structures for disjoint sets"
template < typename _Tp , class _EqPredicate > int
partition ( const std : : vector < _Tp > & _vec , std : : vector < int > & labels ,
_EqPredicate predicate = _EqPredicate ( ) )
{
int i , j , N = ( int ) _vec . size ( ) ;
const _Tp * vec = & _vec [ 0 ] ;
const int PARENT = 0 ;
const int RANK = 1 ;
std : : vector < int > _nodes ( N * 2 ) ;
int ( * nodes ) [ 2 ] = ( int ( * ) [ 2 ] ) & _nodes [ 0 ] ;
// The first O(N) pass: create N single-vertex trees
for ( i = 0 ; i < N ; i + + )
{
nodes [ i ] [ PARENT ] = - 1 ;
nodes [ i ] [ RANK ] = 0 ;
}
// The main O(N^2) pass: merge connected components
for ( i = 0 ; i < N ; i + + )
{
int root = i ;
// find root
while ( nodes [ root ] [ PARENT ] > = 0 )
root = nodes [ root ] [ PARENT ] ;
for ( j = 0 ; j < N ; j + + )
{
if ( i = = j | | ! predicate ( vec [ i ] , vec [ j ] ) )
continue ;
int root2 = j ;
while ( nodes [ root2 ] [ PARENT ] > = 0 )
root2 = nodes [ root2 ] [ PARENT ] ;
if ( root2 ! = root )
{
// unite both trees
int rank = nodes [ root ] [ RANK ] , rank2 = nodes [ root2 ] [ RANK ] ;
if ( rank > rank2 )
nodes [ root2 ] [ PARENT ] = root ;
else
{
nodes [ root ] [ PARENT ] = root2 ;
nodes [ root2 ] [ RANK ] + = rank = = rank2 ;
root = root2 ;
}
CV_Assert ( nodes [ root ] [ PARENT ] < 0 ) ;
int k = j , parent ;
// compress the path from node2 to root
while ( ( parent = nodes [ k ] [ PARENT ] ) > = 0 )
{
nodes [ k ] [ PARENT ] = root ;
k = parent ;
}
// compress the path from node to root
k = i ;
while ( ( parent = nodes [ k ] [ PARENT ] ) > = 0 )
{
nodes [ k ] [ PARENT ] = root ;
k = parent ;
}
}
}
}
// Final O(N) pass: enumerate classes
labels . resize ( N ) ;
int nclasses = 0 ;
for ( i = 0 ; i < N ; i + + )
{
int root = i ;
while ( nodes [ root ] [ PARENT ] > = 0 )
root = nodes [ root ] [ PARENT ] ;
// re-use the rank as the class label
if ( nodes [ root ] [ RANK ] > = 0 )
nodes [ root ] [ RANK ] = ~ nclasses + + ;
labels [ i ] = ~ nodes [ root ] [ RANK ] ;
}
return nclasses ;
}
} // namespace cv
# endif // __OPENCV_CORE_PRIVATE_HPP__
Andrey Kamaev
12 years ago