Tesseract  3.02
tesseract-ocr/classify/kdtree.h File Reference
#include "host.h"
#include "cutil.h"
#include "ocrfeatures.h"

Go to the source code of this file.


struct  KDNODE
struct  KDTREE


#define RootOf(T)   ((T)->Root.Left->Data)


KDTREEMakeKDTree (inT16 KeySize, const PARAM_DESC KeyDesc[])
void KDStore (KDTREE *Tree, FLOAT32 *Key, void *Data)
void KDDelete (KDTREE *Tree, FLOAT32 Key[], void *Data)
void KDNearestNeighborSearch (KDTREE *Tree, FLOAT32 Query[], int QuerySize, FLOAT32 MaxDistance, int *NumberOfResults, void **NBuffer, FLOAT32 DBuffer[])
void KDWalk (KDTREE *Tree, void_proc Action, void *context)
void FreeKDTree (KDTREE *Tree)
KDNODEMakeKDNode (KDTREE *tree, FLOAT32 Key[], void *Data, int Index)
void FreeKDNode (KDNODE *Node)
FLOAT32 DistanceSquared (int k, PARAM_DESC *dim, FLOAT32 p1[], FLOAT32 p2[])
FLOAT32 ComputeDistance (int k, PARAM_DESC *dim, FLOAT32 p1[], FLOAT32 p2[])
int QueryInSearch (KDTREE *tree)
void Walk (KDTREE *tree, void_proc action, void *context, KDNODE *SubTree, inT32 Level)
void InsertNodes (KDTREE *tree, KDNODE *nodes)
void FreeSubTree (KDNODE *SubTree)

Define Documentation

#define RootOf (   T)    ((T)->Root.Left->Data)

Definition at line 58 of file kdtree.h.

Function Documentation

FLOAT32 ComputeDistance ( int  k,
FLOAT32  p1[],
FLOAT32  p2[] 

Definition at line 486 of file kdtree.cpp.

  return sqrt(DistanceSquared(k, dim, p1, p2));
FLOAT32 DistanceSquared ( int  k,
FLOAT32  p1[],
FLOAT32  p2[] 

Definition at line 465 of file kdtree.cpp.

  FLOAT32 total_distance = 0;

  for (; k > 0; k--, p1++, p2++, dim++) {
    if (dim->NonEssential)

    FLOAT32 dimension_distance = *p1 - *p2;

    /* if this dimension is circular - check wraparound distance */
    if (dim->Circular) {
      dimension_distance = Magnitude(dimension_distance);
      FLOAT32 wrap_distance = dim->Max - dim->Min - dimension_distance;
      dimension_distance = MIN(dimension_distance, wrap_distance);

    total_distance += dimension_distance * dimension_distance;
  return total_distance;
void FreeKDNode ( KDNODE Node)

Definition at line 407 of file kdtree.cpp.

  memfree ((char *)Node);
void FreeKDTree ( KDTREE Tree)

Definition at line 346 of file kdtree.cpp.

 **  Parameters:
 **    Tree  tree data structure to be released
 **  Operation:
 **    This routine frees all memory which is allocated to the
 **    specified KD-tree.  This includes the data structure for
 **    the kd-tree itself plus the data structures for each node
 **    in the tree.  It does not include the Key and Data items
 **    which are pointed to by the nodes.  This memory is left
 **    untouched.
 **  Return: none
 **  Exceptions: none
 **  History:
 **    5/26/89, DSJ, Created.
}                                /* FreeKDTree */
void FreeSubTree ( KDNODE SubTree)

Definition at line 568 of file kdtree.cpp.

  if (sub_tree != NULL) {
}                                /* FreeSubTree */
void InsertNodes ( KDTREE tree,
KDNODE nodes 

Definition at line 558 of file kdtree.cpp.

  if (nodes == NULL)

  KDStore(tree, nodes->Key, nodes->Data);
  InsertNodes(tree, nodes->Left);
  InsertNodes(tree, nodes->Right);
void KDDelete ( KDTREE Tree,
FLOAT32  Key[],
void *  Data 

This routine deletes a node from Tree. The node to be deleted is specified by the Key for the node and the Data contents of the node. These two pointers must be identical to the pointers that were used for the node when it was originally stored in the tree. A node will be deleted from the tree only if its key and data pointers are identical to Key and Data respectively. The tree is re-formed by removing the affected subtree and inserting all elements but the root.

TreeK-D tree to delete node from
Keykey of node to be deleted
Datadata contents of node to be deleted
Exceptions: none
History: 3/13/89, DSJ, Created. 7/13/89, DSJ, Specify node indirectly by key and data.

Definition at line 269 of file kdtree.cpp.

  int Level;
  KDNODE *Current;
  KDNODE *Father;

  /* initialize search at root of tree */
  Father = &(Tree->Root);
  Current = Father->Left;
  Level = NextLevel(Tree, -1);

  /* search tree for node to be deleted */
  while ((Current != NULL) && (!NodeFound (Current, Key, Data))) {
    Father = Current;
    if (Key[Level] < Current->BranchPoint)
      Current = Current->Left;
      Current = Current->Right;

    Level = NextLevel(Tree, Level);

  if (Current != NULL) {         /* if node to be deleted was found */
    if (Current == Father->Left) {
      Father->Left = NULL;
      Father->LeftBranch = Tree->KeyDesc[Level].Min;
    } else {
      Father->Right = NULL;
      Father->RightBranch = Tree->KeyDesc[Level].Max;

    InsertNodes(Tree, Current->Left);
    InsertNodes(Tree, Current->Right);
}                                /* KDDelete */
void KDNearestNeighborSearch ( KDTREE Tree,
FLOAT32  Query[],
int  QuerySize,
FLOAT32  MaxDistance,
int *  NumberOfResults,
void **  NBuffer,
FLOAT32  DBuffer[] 

Definition at line 307 of file kdtree.cpp.

 **  Parameters:
 **    Tree    ptr to K-D tree to be searched
 **    Query    ptr to query key (point in D-space)
 **    QuerySize  number of nearest neighbors to be found
 **    MaxDistance  all neighbors must be within this distance
 **    NBuffer    ptr to QuerySize buffer to hold nearest neighbors
 **    DBuffer    ptr to QuerySize buffer to hold distances
 **          from nearest neighbor to query point
 **  Operation:
 **    This routine searches the K-D tree specified by Tree and
 **    finds the QuerySize nearest neighbors of Query.  All neighbors
 **    must be within MaxDistance of Query.  The data contents of
 **    the nearest neighbors
 **    are placed in NBuffer and their distances from Query are
 **    placed in DBuffer.
 **  Return: Number of nearest neighbors actually found
 **  Exceptions: none
 **  History:
 **    3/10/89, DSJ, Created.
 **    7/13/89, DSJ, Return contents of node instead of node itself.
  KDTreeSearch search(Tree, Query, QuerySize);
  search.Search(NumberOfResults, DBuffer, NBuffer);
void KDStore ( KDTREE Tree,
FLOAT32 Key,
void *  Data 

This routine stores Data in the K-D tree specified by Tree using Key as an access key.

TreeK-D tree in which data is to be stored
Keyptr to key by which data can be retrieved
Dataptr to data to be stored in the tree
Exceptions: none
History: 3/10/89, DSJ, Created. 7/13/89, DSJ, Changed return to void.

Definition at line 209 of file kdtree.cpp.

  int Level;
  KDNODE *Node;
  KDNODE **PtrToNode;

  PtrToNode = &(Tree->Root.Left);
  Node = *PtrToNode;
  Level = NextLevel(Tree, -1);
  while (Node != NULL) {
    if (Key[Level] < Node->BranchPoint) {
      PtrToNode = &(Node->Left);
      if (Key[Level] > Node->LeftBranch)
        Node->LeftBranch = Key[Level];
    else {
      PtrToNode = &(Node->Right);
      if (Key[Level] < Node->RightBranch)
        Node->RightBranch = Key[Level];
    Level = NextLevel(Tree, Level);
    Node = *PtrToNode;

  *PtrToNode = MakeKDNode(Tree, Key, (void *) Data, Level);
}                                /* KDStore */
void KDWalk ( KDTREE Tree,
void_proc  Action,
void *  context 

Definition at line 339 of file kdtree.cpp.

  if (Tree->Root.Left != NULL)
    Walk(Tree, action, context, Tree->Root.Left, NextLevel(Tree, -1));
KDNODE* MakeKDNode ( KDTREE tree,
FLOAT32  Key[],
void *  Data,
int  Index 

Definition at line 371 of file kdtree.cpp.

 **  Parameters:
 **      tree  The tree to create the node for
 **      Key  Access key for new node in KD tree
 **      Data  ptr to data to be stored in new node
 **      Index  index of Key to branch on
 **  Operation:
 **    This routine allocates memory for a new K-D tree node
 **    and places the specified Key and Data into it.  The
 **    left and right subtree pointers for the node are
 **    initialized to empty subtrees.
 **  Return:
 **    pointer to new K-D tree node
 **  Exceptions:
 **    None
 **  History:
 **    3/11/89, DSJ, Created.
  KDNODE *NewNode;

  NewNode = (KDNODE *) Emalloc (sizeof (KDNODE));

  NewNode->Key = Key;
  NewNode->Data = Data;
  NewNode->BranchPoint = Key[Index];
  NewNode->LeftBranch = tree->KeyDesc[Index].Min;
  NewNode->RightBranch = tree->KeyDesc[Index].Max;
  NewNode->Left = NULL;
  NewNode->Right = NULL;

  return NewNode;
}                                /* MakeKDNode */
KDTREE* MakeKDTree ( inT16  KeySize,
const PARAM_DESC  KeyDesc[] 

Return a new KDTREE based on the specified parameters. Parameters: KeySize # of dimensions in the K-D tree KeyDesc array of params to describe key dimensions

Definition at line 184 of file kdtree.cpp.

  KDTREE *KDTree = (KDTREE *) Emalloc(
      sizeof(KDTREE) + (KeySize - 1) * sizeof(PARAM_DESC));
  for (int i = 0; i < KeySize; i++) {
    KDTree->KeyDesc[i].NonEssential = KeyDesc[i].NonEssential;
    KDTree->KeyDesc[i].Circular = KeyDesc[i].Circular;
    if (KeyDesc[i].Circular) {
      KDTree->KeyDesc[i].Min = KeyDesc[i].Min;
      KDTree->KeyDesc[i].Max = KeyDesc[i].Max;
      KDTree->KeyDesc[i].Range = KeyDesc[i].Max - KeyDesc[i].Min;
      KDTree->KeyDesc[i].HalfRange = KDTree->KeyDesc[i].Range / 2;
      KDTree->KeyDesc[i].MidRange = (KeyDesc[i].Max + KeyDesc[i].Min) / 2;
    } else {
      KDTree->KeyDesc[i].Min = MINSEARCH;
      KDTree->KeyDesc[i].Max = MAXSEARCH;
  KDTree->KeySize = KeySize;
  KDTree->Root.Left = NULL;
  KDTree->Root.Right = NULL;
  return KDTree;
int QueryInSearch ( KDTREE tree)
void Walk ( KDTREE tree,
void_proc  action,
void *  context,
inT32  Level 

Definition at line 547 of file kdtree.cpp.

  (*action)(context, sub_tree->Data, level);
  if (sub_tree->Left != NULL)
    Walk(tree, action, context, sub_tree->Left, NextLevel(tree, level));
  if (sub_tree->Right != NULL)
    Walk(tree, action, context, sub_tree->Right, NextLevel(tree, level));