tesseract/classify/intfx.cpp

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/******************************************************************************
** Filename: intfx.c
** Purpose: Integer character normalization & feature extraction
** Author: Robert Moss
** History: Tue May 21 15:51:57 MDT 1991, RWM, 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 "intfx.h"
#include "intmatcher.h"
#include "const.h"
#ifdef __UNIX__
#include <assert.h>
#endif
/**----------------------------------------------------------------------------
Private Function Prototypes
----------------------------------------------------------------------------**/
int SaveFeature();
UINT8 TableLookup();
UINT8 MySqrt2();
void ClipRadius();
make_int_var (RadiusGyrMinMan, 255, MakeRadiusGyrMinMan,
16, 10, SetRadiusGyrMinMan,
"Minimum Radius of Gyration Mantissa 0-255: ");
make_int_var (RadiusGyrMinExp, 0, MakeRadiusGyrMinExp,
16, 11, SetRadiusGyrMinExp,
"Minimum Radius of Gyration Exponent 0-255: ");
make_int_var (RadiusGyrMaxMan, 158, MakeRadiusGyrMaxMan,
16, 12, SetRadiusGyrMaxMan,
"Maximum Radius of Gyration Mantissa 0-255: ");
make_int_var (RadiusGyrMaxExp, 8, MakeRadiusGyrMaxExp,
16, 13, SetRadiusGyrMaxExp,
"Maximum Radius of Gyration Exponent 0-255: ");
/**----------------------------------------------------------------------------
Global Data Definitions and Declarations
----------------------------------------------------------------------------**/
#define ATAN_TABLE_SIZE 64
static UINT8 AtanTable[ATAN_TABLE_SIZE];
/**----------------------------------------------------------------------------
Public Code
----------------------------------------------------------------------------**/
/*---------------------------------------------------------------------------*/
void InitIntegerFX() {
int i;
for (i = 0; i < ATAN_TABLE_SIZE; i++)
AtanTable[i] =
(UINT8) (atan ((i / (float) ATAN_TABLE_SIZE)) * 128.0 / PI + 0.5);
}
/*--------------------------------------------------------------------------*/
int ExtractIntFeat(TBLOB *Blob,
INT_FEATURE_ARRAY BLFeat,
INT_FEATURE_ARRAY CNFeat,
INT_FX_RESULT Results) {
TESSLINE *OutLine;
EDGEPT *Loop, *LoopStart, *Segment;
INT16 LastX, LastY, Xmean, Ymean;
INT32 NormX, NormY, DeltaX, DeltaY;
INT32 Xsum, Ysum;
UINT32 Ix, Iy, LengthSum;
UINT16 n;
UINT8 Theta;
UINT16 NumBLFeatures, NumCNFeatures;
UINT8 RxInv, RyInv; /* x.xxxxxxx * 2^Exp */
UINT8 RxExp, RyExp;
/* sxxxxxxxxxxxxxxxxxxxxxxx.xxxxxxxx */
register INT32 pfX, pfY, dX, dY;
UINT16 Length;
register int i;
Results->Length = 0;
Results->Xmean = 0;
Results->Ymean = 0;
Results->Rx = 0;
Results->Ry = 0;
Results->NumBL = 0;
Results->NumCN = 0;
/* find Xmean, Ymean */
NumBLFeatures = 0;
NumCNFeatures = 0;
OutLine = Blob->outlines;
Xsum = 0;
Ysum = 0;
LengthSum = 0;
while (OutLine != NULL) {
LoopStart = OutLine->loop;
Loop = LoopStart;
LastX = Loop->pos.x;
LastY = Loop->pos.y;
/* Check for bad loops */
if ((Loop == NULL) || (Loop->next == NULL) || (Loop->next == LoopStart))
return FALSE;
do {
Segment = Loop;
Loop = Loop->next;
NormX = Loop->pos.x;
NormY = Loop->pos.y;
n = 1;
if (!is_hidden_edge (Segment)) {
DeltaX = NormX - LastX;
DeltaY = NormY - LastY;
Length = MySqrt (DeltaX, DeltaY);
n = ((Length << 2) + Length + 32) >> 6;
if (n != 0) {
Xsum += ((LastX << 1) + DeltaX) * (int) Length;
Ysum += ((LastY << 1) + DeltaY) * (int) Length;
LengthSum += Length;
}
}
if (n != 0) { /* Throw away a point that is too close */
LastX = NormX;
LastY = NormY;
}
}
while (Loop != LoopStart);
OutLine = OutLine->next;
}
if (LengthSum == 0)
return FALSE;
Xmean = (Xsum / (INT32) LengthSum) >> 1;
Ymean = (Ysum / (INT32) LengthSum) >> 1;
Results->Length = LengthSum;
Results->Xmean = Xmean;
Results->Ymean = Ymean;
/* extract Baseline normalized features, */
/* and find 2nd moments & radius of gyration */
Ix = 0;
Iy = 0;
NumBLFeatures = 0;
OutLine = Blob->outlines;
while (OutLine != NULL) {
LoopStart = OutLine->loop;
Loop = LoopStart;
LastX = Loop->pos.x - Xmean;
LastY = Loop->pos.y;
/* Check for bad loops */
if ((Loop == NULL) || (Loop->next == NULL) || (Loop->next == LoopStart))
return FALSE;
do {
Segment = Loop;
Loop = Loop->next;
NormX = Loop->pos.x - Xmean;
NormY = Loop->pos.y;
n = 1;
if (!is_hidden_edge (Segment)) {
DeltaX = NormX - LastX;
DeltaY = NormY - LastY;
Length = MySqrt (DeltaX, DeltaY);
n = ((Length << 2) + Length + 32) >> 6;
if (n != 0) {
Theta = TableLookup (DeltaY, DeltaX);
dX = (DeltaX << 8) / n;
dY = (DeltaY << 8) / n;
pfX = (LastX << 8) + (dX >> 1);
pfY = (LastY << 8) + (dY >> 1);
Ix += ((pfY >> 8) - Ymean) * ((pfY >> 8) - Ymean);
Iy += (pfX >> 8) * (pfX >> 8);
if (SaveFeature (BLFeat, NumBLFeatures, (INT16) (pfX >> 8),
(INT16) ((pfY >> 8) - 128),
Theta) == FALSE)
return FALSE;
NumBLFeatures++;
for (i = 1; i < n; i++) {
pfX += dX;
pfY += dY;
Ix += ((pfY >> 8) - Ymean) * ((pfY >> 8) - Ymean);
Iy += (pfX >> 8) * (pfX >> 8);
if (SaveFeature
(BLFeat, NumBLFeatures, (INT16) (pfX >> 8),
(INT16) ((pfY >> 8) - 128), Theta) == FALSE)
return FALSE;
NumBLFeatures++;
}
}
}
if (n != 0) { /* Throw away a point that is too close */
LastX = NormX;
LastY = NormY;
}
}
while (Loop != LoopStart);
OutLine = OutLine->next;
}
if (Ix == 0)
Ix = 1;
if (Iy == 0)
Iy = 1;
RxInv = MySqrt2 (NumBLFeatures, Ix, &RxExp);
RyInv = MySqrt2 (NumBLFeatures, Iy, &RyExp);
ClipRadius(&RxInv, &RxExp, &RyInv, &RyExp);
Results->Rx = (INT16) (51.2 / (double) RxInv * pow (2.0, (double) RxExp));
Results->Ry = (INT16) (51.2 / (double) RyInv * pow (2.0, (double) RyExp));
Results->NumBL = NumBLFeatures;
/* extract character normalized features */
NumCNFeatures = 0;
OutLine = Blob->outlines;
while (OutLine != NULL) {
LoopStart = OutLine->loop;
Loop = LoopStart;
LastX = (Loop->pos.x - Xmean) * RyInv;
LastY = (Loop->pos.y - Ymean) * RxInv;
LastX >>= (INT8) RyExp;
LastY >>= (INT8) RxExp;
/* Check for bad loops */
if ((Loop == NULL) || (Loop->next == NULL) || (Loop->next == LoopStart))
return FALSE;
do {
Segment = Loop;
Loop = Loop->next;
NormX = (Loop->pos.x - Xmean) * RyInv;
NormY = (Loop->pos.y - Ymean) * RxInv;
NormX >>= (INT8) RyExp;
NormY >>= (INT8) RxExp;
n = 1;
if (!is_hidden_edge (Segment)) {
DeltaX = NormX - LastX;
DeltaY = NormY - LastY;
Length = MySqrt (DeltaX, DeltaY);
n = ((Length << 2) + Length + 32) >> 6;
if (n != 0) {
Theta = TableLookup (DeltaY, DeltaX);
dX = (DeltaX << 8) / n;
dY = (DeltaY << 8) / n;
pfX = (LastX << 8) + (dX >> 1);
pfY = (LastY << 8) + (dY >> 1);
if (SaveFeature (CNFeat, NumCNFeatures, (INT16) (pfX >> 8),
(INT16) ((pfY >> 8)), Theta) == FALSE)
return FALSE;
NumCNFeatures++;
for (i = 1; i < n; i++) {
pfX += dX;
pfY += dY;
if (SaveFeature
(CNFeat, NumCNFeatures, (INT16) (pfX >> 8),
(INT16) ((pfY >> 8)), Theta) == FALSE)
return FALSE;
NumCNFeatures++;
}
}
}
if (n != 0) { /* Throw away a point that is too close */
LastX = NormX;
LastY = NormY;
}
}
while (Loop != LoopStart);
OutLine = OutLine->next;
}
Results->NumCN = NumCNFeatures;
return TRUE;
}
/*--------------------------------------------------------------------------*/
UINT8 TableLookup(INT32 Y, INT32 X) {
INT16 Angle;
UINT16 Ratio;
UINT32 AbsX, AbsY;
assert ((X != 0) || (Y != 0));
if (X < 0)
AbsX = -X;
else
AbsX = X;
if (Y < 0)
AbsY = -Y;
else
AbsY = Y;
if (AbsX > AbsY)
Ratio = AbsY * ATAN_TABLE_SIZE / AbsX;
else
Ratio = AbsX * ATAN_TABLE_SIZE / AbsY;
if (Ratio >= ATAN_TABLE_SIZE)
Ratio = ATAN_TABLE_SIZE - 1;
Angle = AtanTable[Ratio];
if (X >= 0)
if (Y >= 0)
if (AbsX > AbsY)
Angle = Angle;
else
Angle = 64 - Angle;
else if (AbsX > AbsY)
Angle = 256 - Angle;
else
Angle = 192 + Angle;
else if (Y >= 0)
if (AbsX > AbsY)
Angle = 128 - Angle;
else
Angle = 64 + Angle;
else if (AbsX > AbsY)
Angle = 128 + Angle;
else
Angle = 192 - Angle;
/* reverse angles to match old feature extractor: Angle += PI */
Angle += 128;
Angle &= 255;
return (UINT8) Angle;
}
/*--------------------------------------------------------------------------*/
int SaveFeature(INT_FEATURE_ARRAY FeatureArray,
UINT16 FeatureNum,
INT16 X,
INT16 Y,
UINT8 Theta) {
INT_FEATURE Feature;
if (FeatureNum >= MAX_NUM_INT_FEATURES)
return FALSE;
Feature = &(FeatureArray[FeatureNum]);
X = X + 128;
Y = Y + 128;
if (X > 255)
Feature->X = 255;
else if (X < 0)
Feature->X = 0;
else
Feature->X = X;
if (Y > 255)
Feature->Y = 255;
else if (Y < 0)
Feature->Y = 0;
else
Feature->Y = Y;
Feature->Theta = Theta;
return TRUE;
}
/*---------------------------------------------------------------------------*/
UINT16 MySqrt(INT32 X, INT32 Y) {
register UINT16 SqRoot;
register UINT32 Square;
register UINT16 BitLocation;
register UINT32 Sum;
if (X < 0)
X = -X;
if (Y < 0)
Y = -Y;
if (X > EvidenceMultMask)
X = EvidenceMultMask;
if (Y > EvidenceMultMask)
Y = EvidenceMultMask;
Sum = X * X + Y * Y;
BitLocation = 1024;
SqRoot = 0;
do {
Square = (SqRoot | BitLocation) * (SqRoot | BitLocation);
if (Square <= Sum)
SqRoot |= BitLocation;
BitLocation >>= 1;
}
while (BitLocation);
return SqRoot;
}
/*--------------------------------------------------------------------------*/
UINT8 MySqrt2(UINT16 N, UINT32 I, UINT8 *Exp) {
register INT8 k;
register UINT32 N2;
register UINT8 SqRoot;
register UINT16 Square;
register UINT8 BitLocation;
register UINT16 Ratio;
N2 = N * 41943;
k = 9;
while ((N2 & 0xc0000000) == 0) {
N2 <<= 2;
k += 1;
}
while ((I & 0xc0000000) == 0) {
I <<= 2;
k -= 1;
}
if (((N2 & 0x80000000) == 0) && ((I & 0x80000000) == 0)) {
N2 <<= 1;
I <<= 1;
}
N2 &= 0xffff0000;
I >>= 14;
Ratio = N2 / I;
BitLocation = 128;
SqRoot = 0;
do {
Square = (SqRoot | BitLocation) * (SqRoot | BitLocation);
if (Square <= Ratio)
SqRoot |= BitLocation;
BitLocation >>= 1;
}
while (BitLocation);
if (k < 0) {
*Exp = 0;
return 255;
}
else {
*Exp = k;
return SqRoot;
}
}
/*-------------------------------------------------------------------------*/
void ClipRadius(UINT8 *RxInv, UINT8 *RxExp, UINT8 *RyInv, UINT8 *RyExp) {
register UINT8 AM, BM, AE, BE;
register UINT8 BitN, LastCarry;
int RxInvLarge, RyInvSmall;
AM = RadiusGyrMinMan;
AE = RadiusGyrMinExp;
BM = *RxInv;
BE = *RxExp;
LastCarry = 1;
while ((AM != 0) || (BM != 0)) {
if (AE > BE) {
BitN = LastCarry + (AM & 1) + 1;
AM >>= 1;
AE--;
}
else if (AE < BE) {
BitN = LastCarry + (!(BM & 1));
BM >>= 1;
BE--;
}
else { /* AE == BE */
BitN = LastCarry + (AM & 1) + (!(BM & 1));
AM >>= 1;
BM >>= 1;
AE--;
BE--;
}
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
}
BitN = LastCarry + 1;
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
if (BitN == 1) {
*RxInv = RadiusGyrMinMan;
*RxExp = RadiusGyrMinExp;
}
AM = RadiusGyrMinMan;
AE = RadiusGyrMinExp;
BM = *RyInv;
BE = *RyExp;
LastCarry = 1;
while ((AM != 0) || (BM != 0)) {
if (AE > BE) {
BitN = LastCarry + (AM & 1) + 1;
AM >>= 1;
AE--;
}
else if (AE < BE) {
BitN = LastCarry + (!(BM & 1));
BM >>= 1;
BE--;
}
else { /* AE == BE */
BitN = LastCarry + (AM & 1) + (!(BM & 1));
AM >>= 1;
BM >>= 1;
AE--;
BE--;
}
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
}
BitN = LastCarry + 1;
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
if (BitN == 1) {
*RyInv = RadiusGyrMinMan;
*RyExp = RadiusGyrMinExp;
}
AM = RadiusGyrMaxMan;
AE = RadiusGyrMaxExp;
BM = *RxInv;
BE = *RxExp;
LastCarry = 1;
while ((AM != 0) || (BM != 0)) {
if (AE > BE) {
BitN = LastCarry + (AM & 1) + 1;
AM >>= 1;
AE--;
}
else if (AE < BE) {
BitN = LastCarry + (!(BM & 1));
BM >>= 1;
BE--;
}
else { /* AE == BE */
BitN = LastCarry + (AM & 1) + (!(BM & 1));
AM >>= 1;
BM >>= 1;
AE--;
BE--;
}
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
}
BitN = LastCarry + 1;
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
if (BitN == 1)
RxInvLarge = 1;
else
RxInvLarge = 0;
AM = *RyInv;
AE = *RyExp;
BM = RadiusGyrMaxMan;
BE = RadiusGyrMaxExp;
LastCarry = 1;
while ((AM != 0) || (BM != 0)) {
if (AE > BE) {
BitN = LastCarry + (AM & 1) + 1;
AM >>= 1;
AE--;
}
else if (AE < BE) {
BitN = LastCarry + (!(BM & 1));
BM >>= 1;
BE--;
}
else { /* AE == BE */
BitN = LastCarry + (AM & 1) + (!(BM & 1));
AM >>= 1;
BM >>= 1;
AE--;
BE--;
}
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
}
BitN = LastCarry + 1;
LastCarry = (BitN & 2) > 1;
BitN = BitN & 1;
if (BitN == 1)
RyInvSmall = 1;
else
RyInvSmall = 0;
if (RxInvLarge && RyInvSmall) {
*RyInv = RadiusGyrMaxMan;
*RyExp = RadiusGyrMaxExp;
}
}