mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-11-24 02:59:07 +08:00
481 lines
16 KiB
C++
481 lines
16 KiB
C++
/******************************************************************************
|
|
** Filename: mfoutline.c
|
|
** Purpose: Interface to outline struct used for extracting features
|
|
** Author: Dan Johnson
|
|
** History: Thu May 17 08:14:18 1990, DSJ, Created.
|
|
**
|
|
** (c) Copyright Hewlett-Packard Company, 1988.
|
|
** Licensed under the Apache License, Version 2.0 (the "License");
|
|
** you may not use this file except in compliance with the License.
|
|
** You may obtain a copy of the License at
|
|
** http://www.apache.org/licenses/LICENSE-2.0
|
|
** Unless required by applicable law or agreed to in writing, software
|
|
** distributed under the License is distributed on an "AS IS" BASIS,
|
|
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
** See the License for the specific language governing permissions and
|
|
** limitations under the License.
|
|
******************************************************************************/
|
|
/*----------------------------------------------------------------------------
|
|
Include Files and Type Defines
|
|
----------------------------------------------------------------------------*/
|
|
#include "clusttool.h" //If remove you get cought in a loop somewhere
|
|
#include "emalloc.h"
|
|
#include "mfoutline.h"
|
|
#include "blobs.h"
|
|
#include "const.h"
|
|
#include "mfx.h"
|
|
#include "params.h"
|
|
#include "classify.h"
|
|
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
|
|
/*----------------------------------------------------------------------------
|
|
Public Code
|
|
----------------------------------------------------------------------------*/
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** Convert a blob into a list of MFOUTLINEs (float-based microfeature format). */
|
|
LIST ConvertBlob(TBLOB *blob) {
|
|
LIST outlines = NIL_LIST;
|
|
return (blob == NULL)
|
|
? NIL_LIST
|
|
: ConvertOutlines(blob->outlines, outlines, outer);
|
|
}
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** Convert a TESSLINE into the float-based MFOUTLINE micro-feature format. */
|
|
MFOUTLINE ConvertOutline(TESSLINE *outline) {
|
|
MFEDGEPT *NewPoint;
|
|
MFOUTLINE MFOutline = NIL_LIST;
|
|
EDGEPT *EdgePoint;
|
|
EDGEPT *StartPoint;
|
|
EDGEPT *NextPoint;
|
|
|
|
if (outline == NULL || outline->loop == NULL)
|
|
return MFOutline;
|
|
|
|
StartPoint = outline->loop;
|
|
EdgePoint = StartPoint;
|
|
do {
|
|
NextPoint = EdgePoint->next;
|
|
|
|
/* filter out duplicate points */
|
|
if (EdgePoint->pos.x != NextPoint->pos.x ||
|
|
EdgePoint->pos.y != NextPoint->pos.y) {
|
|
NewPoint = NewEdgePoint();
|
|
ClearMark(NewPoint);
|
|
NewPoint->Hidden = EdgePoint->IsHidden();
|
|
NewPoint->Point.x = EdgePoint->pos.x;
|
|
NewPoint->Point.y = EdgePoint->pos.y;
|
|
MFOutline = push(MFOutline, NewPoint);
|
|
}
|
|
EdgePoint = NextPoint;
|
|
} while (EdgePoint != StartPoint);
|
|
|
|
if (MFOutline != NULL)
|
|
MakeOutlineCircular(MFOutline);
|
|
return MFOutline;
|
|
}
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Convert a tree of outlines to a list of MFOUTLINEs (lists of MFEDGEPTs).
|
|
*
|
|
* @param outline first outline to be converted
|
|
* @param mf_outlines list to add converted outlines to
|
|
* @param outline_type are the outlines outer or holes?
|
|
*/
|
|
LIST ConvertOutlines(TESSLINE *outline,
|
|
LIST mf_outlines,
|
|
OUTLINETYPE outline_type) {
|
|
MFOUTLINE mf_outline;
|
|
|
|
while (outline != NULL) {
|
|
mf_outline = ConvertOutline(outline);
|
|
if (mf_outline != NULL)
|
|
mf_outlines = push(mf_outlines, mf_outline);
|
|
outline = outline->next;
|
|
}
|
|
return mf_outlines;
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* This routine searches through the specified outline, computes
|
|
* a slope for each vector in the outline, and marks each
|
|
* vector as having one of the following directions:
|
|
* N, S, E, W, NE, NW, SE, SW
|
|
* This information is then stored in the outline and the
|
|
* outline is returned.
|
|
* @param Outline micro-feature outline to analyze
|
|
* @param MinSlope controls "snapping" of segments to horizontal
|
|
* @param MaxSlope controls "snapping" of segments to vertical
|
|
* @return none
|
|
* @note Exceptions: none
|
|
* @note History: 7/21/89, DSJ, Created.
|
|
*/
|
|
void FindDirectionChanges(MFOUTLINE Outline,
|
|
FLOAT32 MinSlope,
|
|
FLOAT32 MaxSlope) {
|
|
MFEDGEPT *Current;
|
|
MFEDGEPT *Last;
|
|
MFOUTLINE EdgePoint;
|
|
|
|
if (DegenerateOutline (Outline))
|
|
return;
|
|
|
|
Last = PointAt (Outline);
|
|
Outline = NextPointAfter (Outline);
|
|
EdgePoint = Outline;
|
|
do {
|
|
Current = PointAt (EdgePoint);
|
|
ComputeDirection(Last, Current, MinSlope, MaxSlope);
|
|
|
|
Last = Current;
|
|
EdgePoint = NextPointAfter (EdgePoint);
|
|
}
|
|
while (EdgePoint != Outline);
|
|
|
|
} /* FindDirectionChanges */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* This routine deallocates all of the memory consumed by
|
|
* a micro-feature outline.
|
|
* @param arg micro-feature outline to be freed
|
|
* @return none
|
|
* @note Exceptions: none
|
|
* @note History: 7/27/89, DSJ, Created.
|
|
*/
|
|
void FreeMFOutline(void *arg) { //MFOUTLINE Outline)
|
|
MFOUTLINE Start;
|
|
MFOUTLINE Outline = (MFOUTLINE) arg;
|
|
|
|
/* break the circular outline so we can use std. techniques to deallocate */
|
|
Start = list_rest (Outline);
|
|
set_rest(Outline, NIL_LIST);
|
|
while (Start != NULL) {
|
|
free_struct (first_node (Start), sizeof (MFEDGEPT), "MFEDGEPT");
|
|
Start = pop (Start);
|
|
}
|
|
|
|
} /* FreeMFOutline */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Release all memory consumed by the specified list
|
|
* of outlines.
|
|
* @param Outlines list of mf-outlines to be freed
|
|
* @return none
|
|
* @note Exceptions: none
|
|
* @note History: Thu Dec 13 16:14:50 1990, DSJ, Created.
|
|
*/
|
|
void FreeOutlines(LIST Outlines) {
|
|
destroy_nodes(Outlines, FreeMFOutline);
|
|
} /* FreeOutlines */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* This routine searches through the specified outline and finds
|
|
* the points at which the outline changes direction. These
|
|
* points are then marked as "extremities". This routine is
|
|
* used as an alternative to FindExtremities(). It forces the
|
|
* endpoints of the microfeatures to be at the direction
|
|
* changes rather than at the midpoint between direction
|
|
* changes.
|
|
* @param Outline micro-feature outline to analyze
|
|
* @return none
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: 6/29/90, DSJ, Created.
|
|
*/
|
|
void MarkDirectionChanges(MFOUTLINE Outline) {
|
|
MFOUTLINE Current;
|
|
MFOUTLINE Last;
|
|
MFOUTLINE First;
|
|
|
|
if (DegenerateOutline (Outline))
|
|
return;
|
|
|
|
First = NextDirectionChange (Outline);
|
|
Last = First;
|
|
do {
|
|
Current = NextDirectionChange (Last);
|
|
MarkPoint (PointAt (Current));
|
|
Last = Current;
|
|
}
|
|
while (Last != First);
|
|
|
|
} /* MarkDirectionChanges */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/** Return a new edge point for a micro-feature outline. */
|
|
MFEDGEPT *NewEdgePoint() {
|
|
return ((MFEDGEPT *) alloc_struct(sizeof(MFEDGEPT), "MFEDGEPT"));
|
|
}
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* This routine returns the next point in the micro-feature
|
|
* outline that is an extremity. The search starts after
|
|
* EdgePoint. The routine assumes that the outline being
|
|
* searched is not a degenerate outline (i.e. it must have
|
|
* 2 or more edge points).
|
|
* @param EdgePoint start search from this point
|
|
* @return Next extremity in the outline after EdgePoint.
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: 7/26/89, DSJ, Created.
|
|
*/
|
|
MFOUTLINE NextExtremity(MFOUTLINE EdgePoint) {
|
|
EdgePoint = NextPointAfter(EdgePoint);
|
|
while (!PointAt(EdgePoint)->ExtremityMark)
|
|
EdgePoint = NextPointAfter(EdgePoint);
|
|
|
|
return (EdgePoint);
|
|
|
|
} /* NextExtremity */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* This routine normalizes the coordinates of the specified
|
|
* outline so that the outline is deskewed down to the
|
|
* baseline, translated so that x=0 is at XOrigin, and scaled
|
|
* so that the height of a character cell from descender to
|
|
* ascender is 1. Of this height, 0.25 is for the descender,
|
|
* 0.25 for the ascender, and 0.5 for the x-height. The
|
|
* y coordinate of the baseline is 0.
|
|
* @param Outline outline to be normalized
|
|
* @param XOrigin x-origin of text
|
|
* @return none
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: 8/2/89, DSJ, Created.
|
|
*/
|
|
void NormalizeOutline(MFOUTLINE Outline,
|
|
FLOAT32 XOrigin) {
|
|
if (Outline == NIL_LIST)
|
|
return;
|
|
|
|
MFOUTLINE EdgePoint = Outline;
|
|
do {
|
|
MFEDGEPT *Current = PointAt(EdgePoint);
|
|
Current->Point.y = MF_SCALE_FACTOR *
|
|
(Current->Point.y - kBlnBaselineOffset);
|
|
Current->Point.x = MF_SCALE_FACTOR * (Current->Point.x - XOrigin);
|
|
EdgePoint = NextPointAfter(EdgePoint);
|
|
} while (EdgePoint != Outline);
|
|
} /* NormalizeOutline */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
namespace tesseract {
|
|
/**
|
|
* This routine normalizes every outline in Outlines
|
|
* according to the currently selected normalization method.
|
|
* It also returns the scale factors that it used to do this
|
|
* scaling. The scale factors returned represent the x and
|
|
* y sizes in the normalized coordinate system that correspond
|
|
* to 1 pixel in the original coordinate system.
|
|
*
|
|
* Globals:
|
|
* - classify_norm_method method being used for normalization
|
|
* - classify_char_norm_range map radius of gyration to this value
|
|
* @param Outlines list of outlines to be normalized
|
|
* @param XScale x-direction scale factor used by routine
|
|
* @param YScale y-direction scale factor used by routine
|
|
* @return none (Outlines are changed and XScale and YScale are updated)
|
|
* @note Exceptions: none
|
|
* @note History: Fri Dec 14 08:14:55 1990, DSJ, Created.
|
|
*/
|
|
void Classify::NormalizeOutlines(LIST Outlines,
|
|
FLOAT32 *XScale,
|
|
FLOAT32 *YScale) {
|
|
MFOUTLINE Outline;
|
|
|
|
switch (classify_norm_method) {
|
|
case character:
|
|
ASSERT_HOST(!"How did NormalizeOutlines get called in character mode?");
|
|
break;
|
|
|
|
case baseline:
|
|
iterate(Outlines) {
|
|
Outline = (MFOUTLINE) first_node(Outlines);
|
|
NormalizeOutline(Outline, 0.0);
|
|
}
|
|
*XScale = *YScale = MF_SCALE_FACTOR;
|
|
break;
|
|
}
|
|
} /* NormalizeOutlines */
|
|
} // namespace tesseract
|
|
|
|
/*----------------------------------------------------------------------------
|
|
Private Code
|
|
----------------------------------------------------------------------------*/
|
|
/**
|
|
* Change the direction of every vector in the specified
|
|
* outline segment to Direction. The segment to be changed
|
|
* starts at Start and ends at End. Note that the previous
|
|
* direction of End must also be changed to reflect the
|
|
* change in direction of the point before it.
|
|
* @param Start, End defines segment of outline to be modified
|
|
* @param Direction new direction to assign to segment
|
|
* @return none
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: Fri May 4 10:42:04 1990, DSJ, Created.
|
|
*/
|
|
void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction) {
|
|
MFOUTLINE Current;
|
|
|
|
for (Current = Start; Current != End; Current = NextPointAfter (Current))
|
|
PointAt (Current)->Direction = Direction;
|
|
|
|
PointAt (End)->PreviousDirection = Direction;
|
|
|
|
} /* ChangeDirection */
|
|
|
|
|
|
/**
|
|
* This routine normalizes each point in Outline by
|
|
* translating it to the specified center and scaling it
|
|
* anisotropically according to the given scale factors.
|
|
* @param Outline outline to be character normalized
|
|
* @param cn_denorm
|
|
* @return none
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: Fri Dec 14 10:27:11 1990, DSJ, Created.
|
|
*/
|
|
void CharNormalizeOutline(MFOUTLINE Outline, const DENORM& cn_denorm) {
|
|
MFOUTLINE First, Current;
|
|
MFEDGEPT *CurrentPoint;
|
|
|
|
if (Outline == NIL_LIST)
|
|
return;
|
|
|
|
First = Outline;
|
|
Current = First;
|
|
do {
|
|
CurrentPoint = PointAt(Current);
|
|
FCOORD pos(CurrentPoint->Point.x, CurrentPoint->Point.y);
|
|
cn_denorm.LocalNormTransform(pos, &pos);
|
|
CurrentPoint->Point.x = (pos.x() - MAX_UINT8 / 2) * MF_SCALE_FACTOR;
|
|
CurrentPoint->Point.y = (pos.y() - MAX_UINT8 / 2) * MF_SCALE_FACTOR;
|
|
|
|
Current = NextPointAfter(Current);
|
|
}
|
|
while (Current != First);
|
|
|
|
} /* CharNormalizeOutline */
|
|
|
|
|
|
/**
|
|
* This routine computes the slope from Start to Finish and
|
|
* and then computes the approximate direction of the line
|
|
* segment from Start to Finish. The direction is quantized
|
|
* into 8 buckets:
|
|
* N, S, E, W, NE, NW, SE, SW
|
|
* Both the slope and the direction are then stored into
|
|
* the appropriate fields of the Start edge point. The
|
|
* direction is also stored into the PreviousDirection field
|
|
* of the Finish edge point.
|
|
* @param Start starting point to compute direction from
|
|
* @param Finish finishing point to compute direction to
|
|
* @param MinSlope slope below which lines are horizontal
|
|
* @param MaxSlope slope above which lines are vertical
|
|
* @return none
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: 7/25/89, DSJ, Created.
|
|
*/
|
|
void ComputeDirection(MFEDGEPT *Start,
|
|
MFEDGEPT *Finish,
|
|
FLOAT32 MinSlope,
|
|
FLOAT32 MaxSlope) {
|
|
FVECTOR Delta;
|
|
|
|
Delta.x = Finish->Point.x - Start->Point.x;
|
|
Delta.y = Finish->Point.y - Start->Point.y;
|
|
if (Delta.x == 0)
|
|
if (Delta.y < 0) {
|
|
Start->Slope = -MAX_FLOAT32;
|
|
Start->Direction = south;
|
|
}
|
|
else {
|
|
Start->Slope = MAX_FLOAT32;
|
|
Start->Direction = north;
|
|
}
|
|
else {
|
|
Start->Slope = Delta.y / Delta.x;
|
|
if (Delta.x > 0)
|
|
if (Delta.y > 0)
|
|
if (Start->Slope > MinSlope)
|
|
if (Start->Slope < MaxSlope)
|
|
Start->Direction = northeast;
|
|
else
|
|
Start->Direction = north;
|
|
else
|
|
Start->Direction = east;
|
|
else if (Start->Slope < -MinSlope)
|
|
if (Start->Slope > -MaxSlope)
|
|
Start->Direction = southeast;
|
|
else
|
|
Start->Direction = south;
|
|
else
|
|
Start->Direction = east;
|
|
else if (Delta.y > 0)
|
|
if (Start->Slope < -MinSlope)
|
|
if (Start->Slope > -MaxSlope)
|
|
Start->Direction = northwest;
|
|
else
|
|
Start->Direction = north;
|
|
else
|
|
Start->Direction = west;
|
|
else if (Start->Slope > MinSlope)
|
|
if (Start->Slope < MaxSlope)
|
|
Start->Direction = southwest;
|
|
else
|
|
Start->Direction = south;
|
|
else
|
|
Start->Direction = west;
|
|
}
|
|
Finish->PreviousDirection = Start->Direction;
|
|
}
|
|
|
|
/**
|
|
* This routine returns the next point in the micro-feature
|
|
* outline that has a direction different than EdgePoint. The
|
|
* routine assumes that the outline being searched is not a
|
|
* degenerate outline (i.e. it must have 2 or more edge points).
|
|
* @param EdgePoint start search from this point
|
|
* @return Point of next direction change in micro-feature outline.
|
|
* @note Globals: none
|
|
* @note Exceptions: none
|
|
* @note History: 7/25/89, DSJ, Created.
|
|
*/
|
|
MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint) {
|
|
DIRECTION InitialDirection;
|
|
|
|
InitialDirection = PointAt (EdgePoint)->Direction;
|
|
|
|
MFOUTLINE next_pt = NULL;
|
|
do {
|
|
EdgePoint = NextPointAfter(EdgePoint);
|
|
next_pt = NextPointAfter(EdgePoint);
|
|
} while (PointAt(EdgePoint)->Direction == InitialDirection &&
|
|
!PointAt(EdgePoint)->Hidden &&
|
|
next_pt != NULL && !PointAt(next_pt)->Hidden);
|
|
|
|
return (EdgePoint);
|
|
}
|