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https://github.com/tesseract-ocr/tesseract.git
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89 lines
3.1 KiB
C++
89 lines
3.1 KiB
C++
/* -*-C-*-
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********************************************************************************
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*
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* File: context.c (Formerly context.c)
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* Description: Context checking functions
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* Author: Mark Seaman, OCR Technology
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* Created: Thu Feb 15 11:18:24 1990
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* Modified: Tue Jul 9 17:38:16 1991 (Mark Seaman) marks@hpgrlt
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* Language: C
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* Package: N/A
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* Status: Experimental (Do Not Distribute)
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*
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* (c) Copyright 1990, Hewlett-Packard Company.
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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 "dict.h"
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#include "tprintf.h"
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#include "unicharset.h"
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namespace tesseract {
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static const int kMinAbsoluteGarbageWordLength = 10;
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static const float kMinAbsoluteGarbageAlphanumFrac = 0.5f;
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const int case_state_table[6][4] = { {
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/* 0. Beginning of word */
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/* P U L D */
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/* -1. Error on case */
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0, 1, 5, 4
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},
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{ /* 1. After initial capital */
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0, 3, 2, 4
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},
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{ /* 2. After lower case */
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0, -1, 2, -1
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},
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{ /* 3. After upper case */
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0, 3, -1, 4
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},
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{ /* 4. After a digit */
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0, -1, -1, 4
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},
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{ /* 5. After initial lower case */
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5, -1, 2, -1
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},
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};
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int Dict::case_ok(const WERD_CHOICE &word, const UNICHARSET &unicharset) {
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int state = 0;
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int x;
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for (x = 0; x < word.length(); ++x) {
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UNICHAR_ID ch_id = word.unichar_id(x);
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if (unicharset.get_isupper(ch_id))
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state = case_state_table[state][1];
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else if (unicharset.get_islower(ch_id))
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state = case_state_table[state][2];
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else if (unicharset.get_isdigit(ch_id))
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state = case_state_table[state][3];
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else
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state = case_state_table[state][0];
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if (state == -1) return false;
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}
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return state != 5; // single lower is bad
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}
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bool Dict::absolute_garbage(const WERD_CHOICE &word,
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const UNICHARSET &unicharset) {
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if (word.length() < kMinAbsoluteGarbageWordLength) return false;
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int num_alphanum = 0;
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for (int x = 0; x < word.length(); ++x) {
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num_alphanum += (unicharset.get_isalpha(word.unichar_id(x)) ||
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unicharset.get_isdigit(word.unichar_id(x)));
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}
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return (static_cast<float>(num_alphanum) /
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static_cast<float>(word.length()) < kMinAbsoluteGarbageAlphanumFrac);
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}
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} // namespace tesseract
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