mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-12-05 10:49:01 +08:00
4523ce9f7d
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++
/**********************************************************************
|
|
* File: word_unigrams.h
|
|
* Description: Declaration of the Word Unigrams Class
|
|
* Author: Ahmad Abdulkader
|
|
* Created: 2008
|
|
*
|
|
* (C) Copyright 2008, Google Inc.
|
|
** 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.
|
|
*
|
|
**********************************************************************/
|
|
|
|
// The WordUnigram class holds the unigrams of the most frequent set of words
|
|
// in a language. It is an optional component of the Cube OCR engine. If
|
|
// present, the unigram cost of a word is aggregated with the other costs
|
|
// (Recognition, Language Model, Size) to compute a cost for a word.
|
|
// The word list is assumed to be sorted in lexicographic order.
|
|
|
|
#ifndef WORD_UNIGRAMS_H
|
|
#define WORD_UNIGRAMS_H
|
|
|
|
#include <string>
|
|
#include "char_set.h"
|
|
#include "lang_model.h"
|
|
|
|
namespace tesseract {
|
|
class WordUnigrams {
|
|
public:
|
|
WordUnigrams();
|
|
~WordUnigrams();
|
|
// Load the word-list and unigrams from file and create an object
|
|
// The word list is assumed to be sorted
|
|
static WordUnigrams *Create(const string &data_file_path,
|
|
const string &lang);
|
|
// Compute the unigram cost of a UTF-32 string. Splits into
|
|
// space-separated tokens, strips trailing punctuation from each
|
|
// token, evaluates case properties, and calls internal Cost()
|
|
// function on UTF-8 version. To avoid unnecessarily penalizing
|
|
// all-one-case words or capitalized words (first-letter
|
|
// upper-case and remaining letters lower-case) when not all
|
|
// versions of the word appear in the <lang>.cube.word-freq file, a
|
|
// case-invariant cost is computed in those cases, assuming the word
|
|
// meets a minimum length.
|
|
int Cost(const char_32 *str32, LangModel *lang_mod,
|
|
CharSet *char_set, UNICHARSET *unicharset) const;
|
|
protected:
|
|
// Compute the word unigram cost of a UTF-8 string with binary
|
|
// search of sorted words_ array.
|
|
int CostInternal(const char *str) const;
|
|
private:
|
|
// Only words this length or greater qualify for all-numeric or
|
|
// case-invariant word unigram cost.
|
|
static const int kMinLengthNumOrCaseInvariant = 4;
|
|
|
|
int word_cnt_;
|
|
char **words_;
|
|
int *costs_;
|
|
int not_in_list_cost_;
|
|
};
|
|
}
|
|
|
|
#endif // WORD_UNIGRAMS_H
|