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570af48b8b
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@87 d0cd1f9f-072b-0410-8dd7-cf729c803f20
306 lines
10 KiB
C++
306 lines
10 KiB
C++
/******************************************************************************
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** Filename: normmatch.c
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** Purpose: Simple matcher based on character normalization features.
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** Author: Dan Johnson
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** History: Wed Dec 19 16:18:06 1990, DSJ, Created.
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**
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** (c) Copyright Hewlett-Packard Company, 1988.
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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** http://www.apache.org/licenses/LICENSE-2.0
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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******************************************************************************/
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/**----------------------------------------------------------------------------
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Include Files and Type Defines
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----------------------------------------------------------------------------**/
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#include "normmatch.h"
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#include "clusttool.h"
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#include "normfeat.h"
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#include "debug.h"
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#include "const.h"
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#include "efio.h"
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#include "emalloc.h"
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#include "globals.h"
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#include "scanutils.h"
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#include <stdio.h>
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#include <math.h>
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/* define default filenames for training data */
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#define NORM_PROTO_FILE "normproto"
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typedef struct
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{
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int NumParams;
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PARAM_DESC *ParamDesc;
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LIST* Protos;
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int NumProtos;
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} NORM_PROTOS;
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/**----------------------------------------------------------------------------
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Private Function Prototypes
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----------------------------------------------------------------------------**/
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FLOAT32 NormEvidenceOf(register FLOAT32 NormAdj);
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void PrintNormMatch(FILE *File,
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int NumParams,
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PROTOTYPE *Proto,
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FEATURE Feature);
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NORM_PROTOS *ReadNormProtos(FILE *File);
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/**----------------------------------------------------------------------------
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Global Data Definitions and Declarations
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----------------------------------------------------------------------------**/
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/* global data structure to hold char normalization protos */
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static NORM_PROTOS *NormProtos;
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/* name of file containing char normalization protos */
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static const char *NormProtoFile = NORM_PROTO_FILE;
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/* control knobs used to control the normalization adjustment process */
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make_float_var (NormAdjMidpoint, 32.0, MakeNormAdjMidpoint,
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15, 16, SetNormAdjMidpoint, "Norm adjust midpoint ...")
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make_float_var (NormAdjCurl, 2.0, MakeNormAdjCurl,
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15, 17, SetNormAdjCurl, "Norm adjust curl ...")
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/**----------------------------------------------------------------------------
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Public Code
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----------------------------------------------------------------------------**/
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/*---------------------------------------------------------------------------*/
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FLOAT32 ComputeNormMatch(CLASS_ID ClassId, FEATURE Feature, BOOL8 DebugMatch) {
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/*
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** Parameters:
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** ClassId id of class to match against
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** Feature character normalization feature
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** DebugMatch controls dump of debug info
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** Globals:
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** NormProtos character normalization prototypes
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** Operation: This routine compares Features against each character
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** normalization proto for ClassId and returns the match
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** rating of the best match.
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** Return: Best match rating for Feature against protos of ClassId.
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** Exceptions: none
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** History: Wed Dec 19 16:56:12 1990, DSJ, Created.
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*/
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LIST Protos;
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FLOAT32 BestMatch;
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FLOAT32 Match;
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FLOAT32 Delta;
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PROTOTYPE *Proto;
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int ProtoId;
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/* handle requests for classification as noise */
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if (ClassId == NO_CLASS) {
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/* kludge - clean up constants and make into control knobs later */
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Match = (ParamOf (Feature, CharNormLength) *
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ParamOf (Feature, CharNormLength) * 500.0 +
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ParamOf (Feature, CharNormRx) *
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ParamOf (Feature, CharNormRx) * 8000.0 +
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ParamOf (Feature, CharNormRy) *
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ParamOf (Feature, CharNormRy) * 8000.0);
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return (1.0 - NormEvidenceOf (Match));
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}
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BestMatch = MAX_FLOAT32;
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Protos = NormProtos->Protos[ClassId];
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if (DebugMatch) {
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cprintf ("\nFeature = ");
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WriteFeature(stdout, Feature);
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}
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ProtoId = 0;
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iterate(Protos) {
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Proto = (PROTOTYPE *) first_node (Protos);
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Delta = ParamOf (Feature, CharNormY) - Proto->Mean[CharNormY];
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Match = Delta * Delta * Proto->Weight.Elliptical[CharNormY];
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Delta = ParamOf (Feature, CharNormRx) - Proto->Mean[CharNormRx];
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Match += Delta * Delta * Proto->Weight.Elliptical[CharNormRx];
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if (Match < BestMatch)
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BestMatch = Match;
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if (DebugMatch) {
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cprintf ("Proto %1d = ", ProtoId);
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WriteNFloats (stdout, NormProtos->NumParams, Proto->Mean);
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cprintf (" var = ");
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WriteNFloats (stdout, NormProtos->NumParams,
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Proto->Variance.Elliptical);
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cprintf (" match = ");
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PrintNormMatch (stdout, NormProtos->NumParams, Proto, Feature);
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}
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ProtoId++;
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}
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return (1.0 - NormEvidenceOf (BestMatch));
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} /* ComputeNormMatch */
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/*---------------------------------------------------------------------------*/
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void GetNormProtos() {
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/*
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** Parameters: none
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** Globals:
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** NormProtoFile name of file containing normalization protos
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** NormProtos global data structure to hold protos
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** Operation: This routine reads in a set of character normalization
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** protos from NormProtoFile and places them into NormProtos.
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** Return: none
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** Exceptions: none
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** History: Wed Dec 19 16:24:25 1990, DSJ, Created.
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*/
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FILE *File;
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STRING name;
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name = language_data_path_prefix;
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name += NormProtoFile;
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File = Efopen (name.string(), "r");
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NormProtos = ReadNormProtos (File);
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fclose(File);
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} /* GetNormProtos */
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void FreeNormProtos() {
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if (NormProtos != NULL) {
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for (int i = 0; i < NormProtos->NumProtos; i++)
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FreeProtoList(&NormProtos->Protos[i]);
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Efree(NormProtos->Protos);
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Efree(NormProtos->ParamDesc);
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Efree(NormProtos);
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NormProtos = NULL;
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}
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}
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/*---------------------------------------------------------------------------*/
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void InitNormProtoVars() {
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/*
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** Parameters: none
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** Globals:
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** NormProtoFile filename for normalization protos
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** Operation: Initialize the control variables for the normalization
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** matcher.
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** Return: none
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** Exceptions: none
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** History: Mon Nov 5 17:22:10 1990, DSJ, Created.
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*/
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VALUE dummy;
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string_variable (NormProtoFile, "NormProtoFile", NORM_PROTO_FILE);
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MakeNormAdjMidpoint();
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MakeNormAdjCurl();
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} /* InitNormProtoVars */
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/**----------------------------------------------------------------------------
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Private Code
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----------------------------------------------------------------------------**/
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/**********************************************************************
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* NormEvidenceOf
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*
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* Return the new type of evidence number corresponding to this
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* normalization adjustment. The equation that represents the transform is:
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* 1 / (1 + (NormAdj / midpoint) ^ curl)
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**********************************************************************/
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FLOAT32 NormEvidenceOf(register FLOAT32 NormAdj) {
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NormAdj /= NormAdjMidpoint;
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if (NormAdjCurl == 3)
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NormAdj = NormAdj * NormAdj * NormAdj;
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else if (NormAdjCurl == 2)
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NormAdj = NormAdj * NormAdj;
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else
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NormAdj = pow (NormAdj, NormAdjCurl);
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return (1.0 / (1.0 + NormAdj));
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}
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/*---------------------------------------------------------------------------*/
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void PrintNormMatch(FILE *File,
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int NumParams,
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PROTOTYPE *Proto,
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FEATURE Feature) {
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/*
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** Parameters:
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** File open text file to dump match debug info to
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** NumParams # of parameters in proto and feature
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** Proto[] array of prototype parameters
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** Feature[] array of feature parameters
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** Globals: none
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** Operation: This routine dumps out detailed normalization match info.
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** Return: none
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** Exceptions: none
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** History: Wed Jan 2 09:49:35 1991, DSJ, Created.
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*/
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int i;
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FLOAT32 ParamMatch;
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FLOAT32 TotalMatch;
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for (i = 0, TotalMatch = 0.0; i < NumParams; i++) {
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ParamMatch = ((ParamOf (Feature, i) - Mean (Proto, i)) /
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StandardDeviation (Proto, i));
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fprintf (File, " %6.1f", ParamMatch);
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if (i == CharNormY || i == CharNormRx)
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TotalMatch += ParamMatch * ParamMatch;
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}
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fprintf (File, " --> %6.1f (%4.2f)\n",
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TotalMatch, NormEvidenceOf (TotalMatch));
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} /* PrintNormMatch */
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/*---------------------------------------------------------------------------*/
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NORM_PROTOS *ReadNormProtos(FILE *File) {
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/*
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** Parameters:
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** File open text file to read normalization protos from
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** Globals: none
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** Operation: This routine allocates a new data structure to hold
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** a set of character normalization protos. It then fills in
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** the data structure by reading from the specified File.
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** Return: Character normalization protos.
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** Exceptions: none
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** History: Wed Dec 19 16:38:49 1990, DSJ, Created.
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*/
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NORM_PROTOS *NormProtos;
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int i;
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char unichar[UNICHAR_LEN + 1];
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UNICHAR_ID unichar_id;
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LIST Protos;
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int NumProtos;
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/* allocate and initialization data structure */
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NormProtos = (NORM_PROTOS *) Emalloc (sizeof (NORM_PROTOS));
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NormProtos->NumProtos = unicharset.size();
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NormProtos->Protos = (LIST *) Emalloc (NormProtos->NumProtos * sizeof(LIST));
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for (i = 0; i < NormProtos->NumProtos; i++)
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NormProtos->Protos[i] = NIL;
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/* read file header and save in data structure */
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NormProtos->NumParams = ReadSampleSize (File);
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NormProtos->ParamDesc = ReadParamDesc (File, NormProtos->NumParams);
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/* read protos for each class into a separate list */
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while (fscanf (File, "%s %d", unichar, &NumProtos) == 2) {
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if (unicharset.contains_unichar(unichar)) {
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unichar_id = unicharset.unichar_to_id(unichar);
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Protos = NormProtos->Protos[unichar_id];
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for (i = 0; i < NumProtos; i++)
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Protos =
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push_last (Protos, ReadPrototype (File, NormProtos->NumParams));
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NormProtos->Protos[unichar_id] = Protos;
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} else
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cprintf("Error: unichar %s in normproto file is not in unichar set.\n");
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}
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return (NormProtos);
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} /* ReadNormProtos */
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