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git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@526 d0cd1f9f-072b-0410-8dd7-cf729c803f20
70 lines
2.7 KiB
C++
70 lines
2.7 KiB
C++
/**********************************************************************
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* File: word_unigrams.h
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* Description: Declaration of the Word Unigrams Class
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* Author: Ahmad Abdulkader
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* Created: 2008
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*
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* (C) Copyright 2008, Google Inc.
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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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// The WordUnigram class holds the unigrams of the most frequent set of words
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// in a language. It is an optional component of the Cube OCR engine. If
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// present, the unigram cost of a word is aggregated with the other costs
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// (Recognition, Language Model, Size) to compute a cost for a word.
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// The word list is assumed to be sorted in lexicographic order.
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#ifndef WORD_UNIGRAMS_H
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#define WORD_UNIGRAMS_H
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#include <string>
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#include "char_set.h"
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#include "lang_model.h"
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namespace tesseract {
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class WordUnigrams {
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public:
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WordUnigrams();
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~WordUnigrams();
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// Load the word-list and unigrams from file and create an object
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// The word list is assumed to be sorted
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static WordUnigrams *Create(const string &data_file_path,
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const string &lang);
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// Compute the unigram cost of a UTF-32 string. Splits into
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// space-separated tokens, strips trailing punctuation from each
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// token, evaluates case properties, and calls internal Cost()
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// function on UTF-8 version. To avoid unnecessarily penalizing
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// all-one-case words or capitalized words (first-letter
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// upper-case and remaining letters lower-case) when not all
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// versions of the word appear in the <lang>.cube.word-freq file, a
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// case-invariant cost is computed in those cases, assuming the word
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// meets a minimum length.
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int Cost(const char_32 *str32, LangModel *lang_mod,
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CharSet *char_set, UNICHARSET *unicharset) const;
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protected:
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// Compute the word unigram cost of a UTF-8 string with binary
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// search of sorted words_ array.
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int CostInternal(const char *str) const;
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private:
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// Only words this length or greater qualify for all-numeric or
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// case-invariant word unigram cost.
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static const int kMinLengthNumOrCaseInvariant = 4;
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int word_cnt_;
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char **words_;
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int *costs_;
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int not_in_list_cost_;
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};
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}
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#endif // WORD_UNIGRAMS_H
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