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https://github.com/tesseract-ocr/tesseract.git
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109 lines
4.5 KiB
C++
109 lines
4.5 KiB
C++
/******************************************************************************
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** Filename: blobclass.c
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** Purpose: High level blob classification and training routines.
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** Author: Dan Johnson
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** History: 7/21/89, 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 "blobclass.h"
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#include <stdio.h>
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#include "classify.h"
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#include "efio.h"
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#include "featdefs.h"
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#include "mf.h"
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#include "normfeat.h"
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static const char kUnknownFontName[] = "UnknownFont";
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STRING_VAR(classify_font_name, kUnknownFontName,
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"Default font name to be used in training");
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namespace tesseract {
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/**----------------------------------------------------------------------------
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Public Code
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----------------------------------------------------------------------------**/
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// Finds the name of the training font and returns it in fontname, by cutting
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// it out based on the expectation that the filename is of the form:
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// /path/to/dir/[lang].[fontname].exp[num]
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// The [lang], [fontname] and [num] fields should not have '.' characters.
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// If the global parameter classify_font_name is set, its value is used instead.
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void ExtractFontName(const STRING& filename, STRING* fontname) {
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*fontname = classify_font_name;
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if (*fontname == kUnknownFontName) {
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// filename is expected to be of the form [lang].[fontname].exp[num]
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// The [lang], [fontname] and [num] fields should not have '.' characters.
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const char *basename = strrchr(filename.string(), '/');
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const char *firstdot = strchr(basename ? basename : filename.string(), '.');
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const char *lastdot = strrchr(filename.string(), '.');
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if (firstdot != lastdot && firstdot != NULL && lastdot != NULL) {
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++firstdot;
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*fontname = firstdot;
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fontname->truncate_at(lastdot - firstdot);
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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// Extracts features from the given blob and saves them in the tr_file_data_
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// member variable.
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// fontname: Name of font that this blob was printed in.
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// cn_denorm: Character normalization transformation to apply to the blob.
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// fx_info: Character normalization parameters computed with cn_denorm.
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// blob_text: Ground truth text for the blob.
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void Classify::LearnBlob(const STRING& fontname, TBLOB* blob,
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const DENORM& cn_denorm,
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const INT_FX_RESULT_STRUCT& fx_info,
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const char* blob_text) {
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CHAR_DESC CharDesc = NewCharDescription(feature_defs_);
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CharDesc->FeatureSets[0] = ExtractMicros(blob, cn_denorm);
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CharDesc->FeatureSets[1] = ExtractCharNormFeatures(fx_info);
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CharDesc->FeatureSets[2] = ExtractIntCNFeatures(*blob, fx_info);
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CharDesc->FeatureSets[3] = ExtractIntGeoFeatures(*blob, fx_info);
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if (ValidCharDescription(feature_defs_, CharDesc)) {
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// Label the features with a class name and font name.
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tr_file_data_ += "\n";
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tr_file_data_ += fontname;
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tr_file_data_ += " ";
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tr_file_data_ += blob_text;
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tr_file_data_ += "\n";
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// write micro-features to file and clean up
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WriteCharDescription(feature_defs_, CharDesc, &tr_file_data_);
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} else {
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tprintf("Blob learned was invalid!\n");
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}
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FreeCharDescription(CharDesc);
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} // LearnBlob
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// Writes stored training data to a .tr file based on the given filename.
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// Returns false on error.
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bool Classify::WriteTRFile(const STRING& filename) {
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STRING tr_filename = filename + ".tr";
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FILE* fp = Efopen(tr_filename.string(), "wb");
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size_t len = tr_file_data_.length();
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bool result =
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fwrite(&tr_file_data_[0], sizeof(tr_file_data_[0]), len, fp) == len;
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fclose(fp);
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tr_file_data_.truncate_at(0);
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return result;
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}
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} // namespace tesseract.
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