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87e03edb3a
tesseract/dict/dict.cpp
theraysmith@gmail.com fdd4ffe85e Fixed endian bug in dawg reader, Added word bigram correction, 
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@649 d0cd1f9f-072b-0410-8dd7-cf729c803f20
2012-02-02 02:56:18 +00:00

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///////////////////////////////////////////////////////////////////////
// File: dict.cpp
// Description: dict class.
// Author: Samuel Charron
//
// (C) Copyright 2006, 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.
//
///////////////////////////////////////////////////////////////////////
#include <stdio.h>
#include "dict.h"
#include "unicodes.h"
#ifdef _MSC_VER
#pragma warning(disable:4244) // Conversion warnings
#endif
#include "tprintf.h"
namespace tesseract {
class Image;
Dict::Dict(Image* image_ptr)
: letter_is_okay_(&tesseract::Dict::def_letter_is_okay),
probability_in_context_(&tesseract::Dict::def_probability_in_context),
image_ptr_(image_ptr),
STRING_INIT_MEMBER(user_words_suffix, "",
"A list of user-provided words.",
getImage()->getCCUtil()->params()),
STRING_INIT_MEMBER(user_patterns_suffix, "",
"A list of user-provided patterns.",
getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_system_dawg, true, "Load system word dawg.",
getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_freq_dawg, true, "Load frequent word dawg.",
getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_unambig_dawg, true, "Load unambiguous word dawg.",
getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_punc_dawg, true, "Load dawg with punctuation"
" patterns.", getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_number_dawg, true, "Load dawg with number"
" patterns.", getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_fixed_length_dawgs, true, "Load fixed length dawgs"
" (e.g. for non-space delimited languages)",
getImage()->getCCUtil()->params()),
BOOL_INIT_MEMBER(load_bigram_dawg, false, "Load dawg with special word "
"bigrams.", getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_dict_frequent_word, 1.0,
"Score multiplier for word matches which have good case and"
"are frequent in the given language (lower is better).",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_dict_case_ok, 1.1,
"Score multiplier for word matches that have good case "
"(lower is better).", getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_dict_case_bad, 1.3125,
"Default score multiplier for word matches, which may have "
"case issues (lower is better).",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_ngram_best_choice, 1.24,
"Multipler to for the best choice from the ngram model.",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_dict_nonword, 1.25,
"Score multiplier for glyph fragment segmentations which "
"do not match a dictionary word (lower is better).",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_penalty_garbage, 1.50,
"Score multiplier for poorly cased strings that are not in"
" the dictionary and generally look like garbage (lower is"
" better).", getImage()->getCCUtil()->params()),
STRING_MEMBER(output_ambig_words_file, "",
"Output file for ambiguities found in the dictionary",
getImage()->getCCUtil()->params()),
INT_MEMBER(dawg_debug_level, 0, "Set to 1 for general debug info"
", to 2 for more details, to 3 to see all the debug messages",
getImage()->getCCUtil()->params()),
INT_MEMBER(hyphen_debug_level, 0, "Debug level for hyphenated words.",
getImage()->getCCUtil()->params()),
INT_MEMBER(max_viterbi_list_size, 10, "Maximum size of viterbi list.",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(use_only_first_uft8_step, false,
"Use only the first UTF8 step of the given string"
" when computing log probabilities.",
getImage()->getCCUtil()->params()),
double_MEMBER(certainty_scale, 20.0, "Certainty scaling factor",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_nondict_certainty_base, -2.50,
"Certainty threshold for non-dict words",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_phase2_certainty_rejection_offset, 1.0,
"Reject certainty offset",
getImage()->getCCUtil()->params()),
INT_MEMBER(stopper_smallword_size, 2,
"Size of dict word to be treated as non-dict word",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_certainty_per_char, -0.50, "Certainty to add"
" for each dict char above small word size.",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_allowable_character_badness, 3.0,
"Max certaintly variation allowed in a word (in sigma)",
getImage()->getCCUtil()->params()),
INT_MEMBER(stopper_debug_level, 0, "Stopper debug level",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(stopper_no_acceptable_choices, false,
"Make AcceptableChoice() always return false. Useful"
" when there is a need to explore all segmentations",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_ambiguity_threshold_gain, 8.0,
"Gain factor for ambiguity threshold.",
getImage()->getCCUtil()->params()),
double_MEMBER(stopper_ambiguity_threshold_offset, 1.5,
"Certainty offset for ambiguity threshold.",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(save_raw_choices, false, "Save all explored raw choices",
getImage()->getCCUtil()->params()),
INT_MEMBER(tessedit_truncate_wordchoice_log, 10,
"Max words to keep in list",
getImage()->getCCUtil()->params()),
STRING_MEMBER(word_to_debug, "", "Word for which stopper debug"
" information should be printed to stdout",
getImage()->getCCUtil()->params()),
STRING_MEMBER(word_to_debug_lengths, "",
"Lengths of unichars in word_to_debug",
getImage()->getCCUtil()->params()),
INT_MEMBER(fragments_debug, 0, "Debug character fragments",
getImage()->getCCUtil()->params()),
INT_MEMBER(segment_debug, 0, "Debug the whole segmentation process",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(permute_debug, 0, "Debug char permutation process",
getImage()->getCCUtil()->params()),
double_MEMBER(bestrate_pruning_factor, 2.0, "Multiplying factor of"
" current best rate to prune other hypotheses",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(permute_script_word, 0,
"Turn on word script consistency permuter",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(segment_segcost_rating, 0,
"incorporate segmentation cost in word rating?",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(segment_nonalphabetic_script, false,
"Don't use any alphabetic-specific tricks."
"Set to true in the traineddata config file for"
" scripts that are cursive or inherently fixed-pitch",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_reward_script, 0.95,
"Score multipler for script consistency within a word. "
"Being a 'reward' factor, it should be <= 1. "
"Smaller value implies bigger reward.",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(permute_fixed_length_dawg, 0,
"Turn on fixed-length phrasebook search permuter",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(permute_chartype_word, 0,
"Turn on character type (property) consistency permuter",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_reward_chartype, 0.97,
"Score multipler for char type consistency within a word. ",
getImage()->getCCUtil()->params()),
double_MEMBER(segment_reward_ngram_best_choice, 0.99,
"Score multipler for ngram permuter's best choice"
" (only used in the Han script path).",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(save_doc_words, 0, "Save Document Words",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(doc_dict_enable, 1, "Enable Document Dictionary ",
getImage()->getCCUtil()->params()),
double_MEMBER(doc_dict_pending_threshold, 0.0,
"Worst certainty for using pending dictionary",
getImage()->getCCUtil()->params()),
double_MEMBER(doc_dict_certainty_threshold, -2.25,
"Worst certainty for words that can be inserted into the"
"document dictionary", getImage()->getCCUtil()->params()),
BOOL_MEMBER(ngram_permuter_activated, false,
"Activate character-level n-gram-based permuter",
getImage()->getCCUtil()->params()),
INT_MEMBER(max_permuter_attempts, 10000, "Maximum number of different"
" character choices to consider during permutation."
" This limit is especially useful when user patterns"
" are specified, since overly generic patterns can result in"
" dawg search exploring an overly large number of options.",
getImage()->getCCUtil()->params()),
BOOL_MEMBER(permute_only_top, false, "Run only the top choice permuter",
getImage()->getCCUtil()->params()) {
dang_ambigs_table_ = NULL;
replace_ambigs_table_ = NULL;
keep_word_choices_ = false;
reject_offset_ = 0.0;
best_raw_choice_ = NULL;
best_choices_ = NIL_LIST;
raw_choices_ = NIL_LIST;
go_deeper_fxn_ = NULL;
hyphen_word_ = NULL;
last_word_on_line_ = false;
hyphen_unichar_id_ = INVALID_UNICHAR_ID;
document_words_ = NULL;
pending_words_ = NULL;
bigram_dawg_ = NULL;
freq_dawg_ = NULL;
punc_dawg_ = NULL;
max_fixed_length_dawgs_wdlen_ = -1;
wordseg_rating_adjust_factor_ = -1.0f;
output_ambig_words_file_ = NULL;
}
Dict::~Dict() {
if (hyphen_word_ != NULL) delete hyphen_word_;
if (output_ambig_words_file_ != NULL) fclose(output_ambig_words_file_);
}
void Dict::Load() {
STRING name;
STRING &lang = getImage()->getCCUtil()->lang;
if (dawgs_.length() != 0) this->End();
hyphen_unichar_id_ = getUnicharset().unichar_to_id(kHyphenSymbol);
LoadEquivalenceList(kHyphenLikeUTF8);
LoadEquivalenceList(kApostropheLikeUTF8);
TessdataManager &tessdata_manager =
getImage()->getCCUtil()->tessdata_manager;
// Load dawgs_.
if (load_punc_dawg && tessdata_manager.SeekToStart(TESSDATA_PUNC_DAWG)) {
punc_dawg_ = new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_PUNCTUATION, lang, PUNC_PERM,
dawg_debug_level);
dawgs_ += punc_dawg_;
}
if (load_system_dawg && tessdata_manager.SeekToStart(TESSDATA_SYSTEM_DAWG)) {
dawgs_ += new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_WORD, lang, SYSTEM_DAWG_PERM,
dawg_debug_level);
}
if (load_number_dawg && tessdata_manager.SeekToStart(TESSDATA_NUMBER_DAWG)) {
dawgs_ +=
new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_NUMBER, lang, NUMBER_PERM, dawg_debug_level);
}
if (load_bigram_dawg && tessdata_manager.SeekToStart(TESSDATA_BIGRAM_DAWG)) {
bigram_dawg_ = new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_WORD, // doesn't actually matter.
lang,
COMPOUND_PERM, // doesn't actually matter.
dawg_debug_level);
}
if (load_freq_dawg && tessdata_manager.SeekToStart(TESSDATA_FREQ_DAWG)) {
freq_dawg_ = new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_WORD, lang, FREQ_DAWG_PERM,
dawg_debug_level);
dawgs_ += freq_dawg_;
}
if (load_unambig_dawg &&
tessdata_manager.SeekToStart(TESSDATA_UNAMBIG_DAWG)) {
unambig_dawg_ = new SquishedDawg(tessdata_manager.GetDataFilePtr(),
DAWG_TYPE_WORD, lang, SYSTEM_DAWG_PERM,
dawg_debug_level);
dawgs_ += unambig_dawg_;
}
if (((STRING &)user_words_suffix).length() > 0) {
Trie *trie_ptr = new Trie(DAWG_TYPE_WORD, lang, USER_DAWG_PERM,
kMaxUserDawgEdges, getUnicharset().size(),
dawg_debug_level);
name = getImage()->getCCUtil()->language_data_path_prefix;
name += user_words_suffix;
if (!trie_ptr->read_word_list(name.string(), getUnicharset(),
Trie::RRP_REVERSE_IF_HAS_RTL)) {
tprintf("Error: failed to load %s\n", name.string());
exit(1);
}
dawgs_ += trie_ptr;
}
if (((STRING &)user_patterns_suffix).length() > 0) {
Trie *trie_ptr = new Trie(DAWG_TYPE_PATTERN, lang, USER_PATTERN_PERM,
kMaxUserDawgEdges, getUnicharset().size(),
dawg_debug_level);
trie_ptr->initialize_patterns(&(getUnicharset()));
name = getImage()->getCCUtil()->language_data_path_prefix;
name += user_patterns_suffix;
if (!trie_ptr->read_pattern_list(name.string(), getUnicharset())) {
tprintf("Error: failed to load %s\n", name.string());
exit(1);
}
dawgs_ += trie_ptr;
}
document_words_ = new Trie(DAWG_TYPE_WORD, lang, DOC_DAWG_PERM,
kMaxDocDawgEdges, getUnicharset().size(),
dawg_debug_level);
dawgs_ += document_words_;
// This dawg is temporary and should not be searched by letter_is_ok.
pending_words_ = new Trie(DAWG_TYPE_WORD, lang, NO_PERM,
kMaxDocDawgEdges, getUnicharset().size(),
dawg_debug_level);
// Load fixed length dawgs if necessary (used for phrase search
// for non-space delimited languages).
if (load_fixed_length_dawgs &&
tessdata_manager.SeekToStart(TESSDATA_FIXED_LENGTH_DAWGS)) {
ReadFixedLengthDawgs(DAWG_TYPE_WORD, lang, SYSTEM_DAWG_PERM,
dawg_debug_level, tessdata_manager.GetDataFilePtr(),
&dawgs_, &max_fixed_length_dawgs_wdlen_);
}
// Construct a list of corresponding successors for each dawg. Each entry i
// in the successors_ vector is a vector of integers that represent the
// indices into the dawgs_ vector of the successors for dawg i.
successors_.reserve(dawgs_.length());
for (int i = 0; i < dawgs_.length(); ++i) {
const Dawg *dawg = dawgs_[i];
SuccessorList *lst = new SuccessorList();
for (int j = 0; j < dawgs_.length(); ++j) {
const Dawg *other = dawgs_[j];
if (dawg != NULL && other != NULL &&
(dawg->lang() == other->lang()) &&
kDawgSuccessors[dawg->type()][other->type()]) *lst += j;
}
successors_ += lst;
}
}
void Dict::End() {
if (dawgs_.length() == 0)
return; // Not safe to call twice.
dawgs_.delete_data_pointers();
successors_.delete_data_pointers();
dawgs_.clear();
delete bigram_dawg_;
successors_.clear();
document_words_ = NULL;
max_fixed_length_dawgs_wdlen_ = -1;
if (pending_words_ != NULL) {
delete pending_words_;
pending_words_ = NULL;
}
}
// Create unicharset adaptations of known, short lists of UTF-8 equivalent
// characters (think all hyphen-like symbols). The first version of the
// list is taken as equivalent for matching against the dictionary.
void Dict::LoadEquivalenceList(const char *unichar_strings[]) {
equivalent_symbols_.push_back(GenericVectorEqEq<UNICHAR_ID>());
const UNICHARSET &unicharset = getUnicharset();
GenericVectorEqEq<UNICHAR_ID> *equiv_list = &equivalent_symbols_.back();
for (int i = 0; unichar_strings[i] != 0; i++) {
UNICHAR_ID unichar_id = unicharset.unichar_to_id(unichar_strings[i]);
if (unichar_id != INVALID_UNICHAR_ID) {
equiv_list->push_back(unichar_id);
}
}
}
// Normalize all hyphen and apostrophes to the canonicalized one for
// matching; pass everything else through as is.
UNICHAR_ID Dict::NormalizeUnicharIdForMatch(UNICHAR_ID unichar_id) const {
for (int i = 0; i < equivalent_symbols_.size(); i++) {
if (equivalent_symbols_[i].contains(unichar_id)) {
return equivalent_symbols_[i][0];
}
}
return unichar_id;
}
// Returns true if in light of the current state unichar_id is allowed
// according to at least one of the dawgs in the dawgs_ vector.
// See more extensive comments in dict.h where this function is declared.
int Dict::def_letter_is_okay(void* void_dawg_args,
UNICHAR_ID unichar_id,
bool word_end) const {
DawgArgs *dawg_args = reinterpret_cast<DawgArgs*>(void_dawg_args);
if (dawg_debug_level >= 3) {
tprintf("def_letter_is_okay: current unichar=%s word_end=%d"
" num active dawgs=%d num constraints=%d\n",
getUnicharset().debug_str(unichar_id).string(), word_end,
dawg_args->active_dawgs->length(),
dawg_args->constraints->length());
}
// Do not accept words that contain kPatternUnicharID.
// (otherwise pattern dawgs would not function correctly).
// Do not accept words containing INVALID_UNICHAR_IDs.
if (unichar_id == Dawg::kPatternUnicharID ||
unichar_id == INVALID_UNICHAR_ID) {
dawg_args->permuter = NO_PERM;
return NO_PERM;
}
// Initialization.
PermuterType curr_perm = NO_PERM;
dawg_args->updated_active_dawgs->clear();
const DawgInfoVector &constraints = *(dawg_args->constraints);
*dawg_args->updated_constraints = constraints;
// Go over the active_dawgs vector and insert DawgInfo records with the
// updated ref (an edge with the corresponding unichar id) into
// dawg_args->updated_active_dawgs.
for (int a = 0; a < dawg_args->active_dawgs->length(); ++a) {
const DawgInfo &info = (*dawg_args->active_dawgs)[a];
const Dawg *dawg = dawgs_[info.dawg_index];
// dawg_unichar_id will contain the literal unichar_id to be found in the
// dawgs (e.g. didgit pattern if unichar_id is a digit and dawg contains
// number patterns, word pattern if dawg is a puncutation dawg and we
// reached an end of beginning puntuation pattern, etc).
UNICHAR_ID dawg_unichar_id = unichar_id;
// If we are dealing with the pattern dawg, look up all the
// possible edges, not only for the exact unichar_id, but also
// for all its character classes (alpha, digit, etc).
if (dawg->type() == DAWG_TYPE_PATTERN) {
ProcessPatternEdges(dawg, info, dawg_unichar_id, word_end,
dawg_args, &curr_perm);
// There can't be any successors to dawg that is of type
// DAWG_TYPE_PATTERN, so we are done examining this DawgInfo.
continue;
}
// The number dawg generalizes all digits to be kPatternUnicharID,
// so try to match kPatternUnicharID if the current unichar is a digit.
if (dawg->type() == DAWG_TYPE_NUMBER &&
getUnicharset().get_isdigit(dawg_unichar_id)) {
dawg_unichar_id = Dawg::kPatternUnicharID;
}
// Find the edge out of the node for the dawg_unichar_id.
NODE_REF node = GetStartingNode(dawg, info.ref);
EDGE_REF edge = (node != NO_EDGE) ?
dawg->edge_char_of(node, dawg_unichar_id, word_end) : NO_EDGE;
if (dawg_debug_level >= 3) {
tprintf("Active dawg: [%d, " REFFORMAT "] edge=" REFFORMAT "\n",
info.dawg_index, node, edge);
}
if (edge != NO_EDGE) { // the unichar was found in the current dawg
if (ConstraintsOk(*(dawg_args->updated_constraints),
word_end, dawg->type())) {
if (dawg_debug_level >=3) {
tprintf("Letter found in dawg %d\n", info.dawg_index);
}
if (dawg->permuter() > curr_perm) curr_perm = dawg->permuter();
dawg_args->updated_active_dawgs->add_unique(
DawgInfo(info.dawg_index, edge), dawg_debug_level > 0,
"Append current dawg to updated active dawgs: ");
}
} else if (dawg_args->sought_word_length == kAnyWordLength) {
// The unichar was not found in the current dawg.
// Explore the successor dawgs (but only if we are not
// just searching one dawg with a fixed word length).
// Handle leading/trailing punctuation dawgs that denote a word pattern
// as an edge with kPatternUnicharID. If such an edge is found we add a
// constraint denoting the state of the dawg before the word pattern.
// This constraint will be applied later when this dawg is found among
// successor dawgs as well potentially at the end of the word.
if (dawg->type() == DAWG_TYPE_PUNCTUATION) {
edge = dawg->edge_char_of(node, Dawg::kPatternUnicharID, word_end);
if (edge != NO_EDGE) {
dawg_args->updated_constraints->add_unique(
DawgInfo(info.dawg_index, edge), dawg_debug_level > 0,
"Recording constraint: ");
} else {
// Do not explore successors of this dawg, since this
// must be invalid leading or trailing punctuation.
if (dawg_debug_level >= 3) {
tprintf("Invalid punctuation from dawg %d\n", info.dawg_index);
}
continue;
}
}
if (info.ref == NO_EDGE) {
if (dawg_debug_level >= 3) {
tprintf("No letters matched in dawg %d\n", info.dawg_index);
}
continue;
}
// Discard the dawg if the pattern can not end at previous letter.
if (edge == NO_EDGE && // previous part is not leading punctuation
!dawg->end_of_word(info.ref)) {
if (dawg_debug_level >= 3) {
tprintf("No valid pattern end in dawg %d\n", info.dawg_index);
}
continue;
}
// Look for the unichar in each of this dawg's successors
// and append those in which it is found to active_dawgs.
const SuccessorList &slist = *(successors_[info.dawg_index]);
for (int s = 0; s < slist.length(); ++s) {
int sdawg_index = slist[s];
const Dawg *sdawg = dawgs_[sdawg_index];
NODE_REF snode = 0;
// Apply constraints to the successor dawg.
for (int c = 0; c < constraints.length(); ++c) {
// If the successor dawg is described in the constraints change
// the start ref from 0 to the one recorded as the constraint.
const DawgInfo &cinfo = constraints[c];
if (cinfo.dawg_index == sdawg_index) {
snode = sdawg->next_node(cinfo.ref);
// Make sure we do not search the successor dawg if after
// applying the saved constraint we are at the end of the word.
if (snode == 0) snode = NO_EDGE;
if (dawg_debug_level >= 3) {
tprintf("Applying constraint [%d, " REFFORMAT "]\n",
sdawg_index, snode);
}
}
}
// Look for the letter in this successor dawg.
EDGE_REF sedge = sdawg->edge_char_of(snode, unichar_id, word_end);
// If we found the letter append sdawg to the active_dawgs list.
if (sedge != NO_EDGE &&
ConstraintsOk(*(dawg_args->updated_constraints), word_end,
dawgs_[sdawg_index]->type())) {
if (dawg_debug_level >= 3) {
tprintf("Letter found in the successor dawg %d\n", sdawg_index);
}
if (sdawg->permuter() > curr_perm) curr_perm = sdawg->permuter();
if (sdawg->next_node(sedge) != 0) { // if not word end
dawg_args->updated_active_dawgs->add_unique(
DawgInfo(sdawg_index, sedge), dawg_debug_level > 0,
"Append successor to updated active dawgs: ");
}
}
} // end successors loop
} // end if/else
} // end for
// Update dawg_args->permuter if it used to be NO_PERM or became NO_PERM
// or if we found the current letter in a non-punctuation dawg. This
// allows preserving information on which dawg the "core" word came from.
// Keep the old value of dawg_args->permuter if it is COMPOUND_PERM.
if (dawg_args->permuter == NO_PERM || curr_perm == NO_PERM ||
(curr_perm != PUNC_PERM && dawg_args->permuter != COMPOUND_PERM)) {
dawg_args->permuter = curr_perm;
}
return dawg_args->permuter;
}
void Dict::ProcessPatternEdges(const Dawg *dawg, const DawgInfo &info,
UNICHAR_ID unichar_id, bool word_end,
DawgArgs *dawg_args,
PermuterType *curr_perm) const {
NODE_REF node = GetStartingNode(dawg, info.ref);
// Try to find the edge corresponding to the exact unichar_id and to all the
// edges corresponding to the character class of unichar_id.
GenericVector<UNICHAR_ID> unichar_id_patterns;
unichar_id_patterns.push_back(unichar_id);
dawg->unichar_id_to_patterns(unichar_id, getUnicharset(),
&unichar_id_patterns);
for (int i = 0; i < unichar_id_patterns.size(); ++i) {
// On the first iteration check all the outgoing edges.
// On the second iteration check all self-loops.
for (int k = 0; k < 2; ++k) {
EDGE_REF edge = (k == 0) ?
dawg->edge_char_of(node, unichar_id_patterns[i], word_end)
: dawg->pattern_loop_edge(info.ref, unichar_id_patterns[i], word_end);
if (edge != NO_EDGE) {
if (dawg_debug_level >= 3) {
tprintf("Pattern dawg: [%d, " REFFORMAT "] edge=" REFFORMAT "\n",
info.dawg_index, node, edge);
}
if (ConstraintsOk(*(dawg_args->updated_constraints),
word_end, dawg->type())) {
if (dawg_debug_level >=3) {
tprintf("Letter found in pattern dawg %d\n", info.dawg_index);
}
if (dawg->permuter() > *curr_perm) *curr_perm = dawg->permuter();
dawg_args->updated_active_dawgs->add_unique(
DawgInfo(info.dawg_index, edge), dawg_debug_level > 0,
"Append current dawg to updated active dawgs: ");
}
}
}
}
}
void Dict::ReadFixedLengthDawgs(DawgType type, const STRING &lang,
PermuterType perm, int debug_level,
FILE *file, DawgVector *dawg_vec,
int *max_wdlen) {
int i;
DawgVector dawg_vec_copy;
dawg_vec_copy.move(dawg_vec); // save the input dawg_vec.
inT32 num_dawgs;
fread(&num_dawgs, sizeof(inT32), 1, file);
bool swap = (num_dawgs > MAX_WERD_LENGTH);
if (swap) num_dawgs = reverse32(num_dawgs);
inT32 word_length;
int max_word_length = 0;
// Read and record pointers to fixed-length dawgs such that:
// dawg_vec[word_length] = pointer to dawg with word length of word_length,
// NULL if such fixed-length dawg does not exist.
for (i = 0; i < num_dawgs; ++i) {
fread(&word_length, sizeof(inT32), 1, file);
if (swap) word_length = reverse32(word_length);
ASSERT_HOST(word_length > 0 && word_length <= MAX_WERD_LENGTH);
while (word_length >= dawg_vec->size()) dawg_vec->push_back(NULL);
(*dawg_vec)[word_length] =
new SquishedDawg(file, type, lang, perm, debug_level);
if (word_length > max_word_length) max_word_length = word_length;
}
*max_wdlen = max_word_length;
// Entries dawg_vec[0] to dawg_vec[max_word_length] now hold pointers
// to fixed-length dawgs. The rest of the vector will contain the dawg
// pointers from the original input dawg_vec.
for (i = 0; i < dawg_vec_copy.size(); ++i) {
dawg_vec->push_back(dawg_vec_copy[i]);
}
}
void Dict::WriteFixedLengthDawgs(
const GenericVector<SquishedDawg *> &dawg_vec,
int num_dawgs, int debug_level, FILE *output_file) {
fwrite(&num_dawgs, sizeof(inT32), 1, output_file);
if (debug_level) tprintf("Writing %d split length dawgs\n", num_dawgs);
for (int i = 1; i < dawg_vec.size(); ++i) {
if ((dawg_vec)[i] != NULL) {
fwrite(&i, sizeof(inT32), 1, output_file);
dawg_vec[i]->write_squished_dawg(output_file);
if (debug_level) tprintf("Wrote Dawg with word length %d\n", i);
}
}
}
// Fill the given active_dawgs vector with dawgs that could contain the
// beginning of the word. If hyphenated() returns true, copy the entries
// from hyphen_active_dawgs_ instead.
void Dict::init_active_dawgs(int sought_word_length,
DawgInfoVector *active_dawgs,
bool ambigs_mode) const {
int i;
if (sought_word_length != kAnyWordLength) {
// Only search one fixed word length dawg.
if (sought_word_length <= max_fixed_length_dawgs_wdlen_ &&
dawgs_[sought_word_length] != NULL) {
*active_dawgs += DawgInfo(sought_word_length, NO_EDGE);
}
} else if (hyphenated()) {
*active_dawgs = hyphen_active_dawgs_;
if (dawg_debug_level >= 3) {
for (i = 0; i < hyphen_active_dawgs_.size(); ++i) {
tprintf("Adding hyphen beginning dawg [%d, " REFFORMAT "]\n",
hyphen_active_dawgs_[i].dawg_index,
hyphen_active_dawgs_[i].ref);
}
}
} else {
for (i = 0; i < dawgs_.length(); ++i) {
if (dawgs_[i] != NULL && kBeginningDawgsType[(dawgs_[i])->type()] &&
!(ambigs_mode && (dawgs_[i])->type() == DAWG_TYPE_PATTERN)) {
*active_dawgs += DawgInfo(i, NO_EDGE);
if (dawg_debug_level >= 3) {
tprintf("Adding beginning dawg [%d, " REFFORMAT "]\n", i, NO_EDGE);
}
}
}
}
}
// If hyphenated() returns true, copy the entries from hyphen_constraints_
// into the given constraints vector.
void Dict::init_constraints(DawgInfoVector *constraints) const {
if (hyphenated()) {
*constraints = hyphen_constraints_;
if (dawg_debug_level >= 3) {
for (int i = 0; i < hyphen_constraints_.size(); ++i) {
tprintf("Adding hyphen constraint [%d, " REFFORMAT "]\n",
hyphen_constraints_[i].dawg_index,
hyphen_constraints_[i].ref);
}
}
}
}
void Dict::add_document_word(const WERD_CHOICE &best_choice) {
// Do not add hyphenated word parts to the document dawg.
// hyphen_word_ will be non-NULL after the set_hyphen_word() is
// called when the first part of the hyphenated word is
// discovered and while the second part of the word is recognized.
// hyphen_word_ is cleared in cc_recg() before the next word on
// the line is recognized.
if (hyphen_word_) return;
char filename[CHARS_PER_LINE];
FILE *doc_word_file;
int stringlen = best_choice.length();
if (!doc_dict_enable || valid_word(best_choice) ||
CurrentWordAmbig() || stringlen < 2)
return;
// Discard words that contain >= kDocDictMaxRepChars repeating unichars.
if (best_choice.length() >= kDocDictMaxRepChars) {
int num_rep_chars = 1;
UNICHAR_ID uch_id = best_choice.unichar_id(0);
for (int i = 1; i < best_choice.length(); ++i) {
if (best_choice.unichar_id(i) != uch_id) {
num_rep_chars = 1;
uch_id = best_choice.unichar_id(i);
} else {
++num_rep_chars;
if (num_rep_chars == kDocDictMaxRepChars) return;
}
}
}
if (best_choice.certainty() < doc_dict_certainty_threshold ||
stringlen == 2) {
if (best_choice.certainty() < doc_dict_pending_threshold)
return;
if (!pending_words_->word_in_dawg(best_choice)) {
if (stringlen > 2 ||
(stringlen == 2 &&
getUnicharset().get_isupper(best_choice.unichar_id(0)) &&
getUnicharset().get_isupper(best_choice.unichar_id(1)))) {
pending_words_->add_word_to_dawg(best_choice);
}
return;
}
}
if (save_doc_words) {
strcpy(filename, getImage()->getCCUtil()->imagefile.string());
strcat(filename, ".doc");
doc_word_file = open_file (filename, "a");
fprintf(doc_word_file, "%s\n",
best_choice.debug_string().string());
fclose(doc_word_file);
}
document_words_->add_word_to_dawg(best_choice);
}
void Dict::adjust_word(WERD_CHOICE *word,
float *certainty_array,
const BLOB_CHOICE_LIST_VECTOR *char_choices,
bool nonword,
float additional_adjust,
bool debug) {
bool is_han = (char_choices != NULL &&
getUnicharset().han_sid() != getUnicharset().null_sid() &&
get_top_word_script(*char_choices, getUnicharset()) ==
getUnicharset().han_sid());
bool case_is_ok = (is_han || case_ok(*word, getUnicharset()));
bool punc_is_ok = (is_han || !nonword || valid_punctuation(*word));
float adjust_factor = additional_adjust;
float new_rating = word->rating();
if (debug) {
tprintf("%sWord: %s %4.2f ", nonword ? "Non-" : "",
word->debug_string().string(), word->rating());
}
new_rating += kRatingPad;
if (nonword) { // non-dictionary word
if (case_is_ok && punc_is_ok) {
adjust_factor += segment_penalty_dict_nonword;
new_rating *= adjust_factor;
if (debug) tprintf(", W");
} else {
adjust_factor += segment_penalty_garbage;
new_rating *= adjust_factor;
if (debug) {
if (!case_is_ok) tprintf(", C");
if (!punc_is_ok) tprintf(", P");
}
}
} else { // dictionary word
if (case_is_ok) {
if (!is_han && freq_dawg_ != NULL && freq_dawg_->word_in_dawg(*word)) {
word->set_permuter(FREQ_DAWG_PERM);
adjust_factor += segment_penalty_dict_frequent_word;
new_rating *= adjust_factor;
if (debug) tprintf(", F");
} else {
adjust_factor += segment_penalty_dict_case_ok;
new_rating *= adjust_factor;
if (debug) tprintf(", ");
}
} else {
adjust_factor += segment_penalty_dict_case_bad;
new_rating *= adjust_factor;
if (debug) tprintf(", C");
}
}
new_rating -= kRatingPad;
word->set_rating(new_rating);
if (debug) tprintf(" %4.2f --> %4.2f\n", adjust_factor, new_rating);
LogNewChoice(adjust_factor, certainty_array, false, word);
}
int Dict::valid_word(const WERD_CHOICE &word, bool numbers_ok) const {
const WERD_CHOICE *word_ptr = &word;
WERD_CHOICE temp_word(word.unicharset());
if (hyphenated()) {
copy_hyphen_info(&temp_word);
temp_word += word;
word_ptr = &temp_word;
}
if (word_ptr->length() == 0) return NO_PERM;
// Allocate vectors for holding current and updated
// active_dawgs and constraints and initialize them.
DawgInfoVector *active_dawgs = new DawgInfoVector[2];
DawgInfoVector *constraints = new DawgInfoVector[2];
init_active_dawgs(kAnyWordLength, &(active_dawgs[0]), false);
init_constraints(&(constraints[0]));
DawgArgs dawg_args(&(active_dawgs[0]), &(constraints[0]),
&(active_dawgs[1]), &(constraints[1]),
0.0, NO_PERM, kAnyWordLength, 0);
int last_index = word_ptr->length() - 1;
// Call leter_is_okay for each letter in the word.
for (int i = hyphen_base_size(); i <= last_index; ++i) {
if (!((this->*letter_is_okay_)(&dawg_args, word_ptr->unichar_id(i),
i == last_index))) break;
// Swap active_dawgs, constraints with the corresponding updated vector.
if (dawg_args.updated_active_dawgs == &(active_dawgs[1])) {
dawg_args.updated_active_dawgs = &(active_dawgs[0]);
dawg_args.updated_constraints = &(constraints[0]);
++(dawg_args.active_dawgs);
++(dawg_args.constraints);
} else {
++(dawg_args.updated_active_dawgs);
++(dawg_args.updated_constraints);
dawg_args.active_dawgs = &(active_dawgs[0]);
dawg_args.constraints = &(constraints[0]);
}
}
delete[] active_dawgs;
delete[] constraints;
return valid_word_permuter(dawg_args.permuter, numbers_ok) ?
dawg_args.permuter : NO_PERM;
}
bool Dict::valid_bigram(const WERD_CHOICE &word1,
const WERD_CHOICE &word2) const {
if (bigram_dawg_ == NULL) return false;
// Extract the core word from the middle of each word with any digits
// replaced with question marks.
int w1start, w1end, w2start, w2end;
word1.punct_stripped(&w1start, &w1end);
word2.punct_stripped(&w2start, &w2end);
// We don't want to penalize a single guillemet, hyphen, etc.
// But our bigram list doesn't have any information about punctuation.
if (w1start >= w1end) return word1.length() < 3;
if (w2start >= w2end) return word2.length() < 3;
const UNICHARSET& uchset = getUnicharset();
STRING bigram_string;
for (int i = w1start; i < w1end; i++) {
UNICHAR_ID ch = NormalizeUnicharIdForMatch(word1.unichar_id(i));
bigram_string += uchset.get_isdigit(ch) ? "?" : uchset.id_to_unichar(ch);
}
bigram_string += " ";
for (int i = w2start; i < w2end; i++) {
UNICHAR_ID ch = NormalizeUnicharIdForMatch(word2.unichar_id(i));
bigram_string += uchset.get_isdigit(ch) ? "?" : uchset.id_to_unichar(ch);
}
WERD_CHOICE normalized_word(bigram_string.string(), uchset);
return bigram_dawg_->word_in_dawg(normalized_word);
}
bool Dict::valid_punctuation(const WERD_CHOICE &word) {
if (word.length() == 0) return NO_PERM;
int i;
WERD_CHOICE new_word(word.unicharset());
int last_index = word.length() - 1;
int new_len = 0;
for (i = 0; i <= last_index; ++i) {
UNICHAR_ID unichar_id = (word.unichar_id(i));
if (getUnicharset().get_ispunctuation(unichar_id)) {
new_word.append_unichar_id(unichar_id, 1, 0.0, 0.0);
} else if (!getUnicharset().get_isalpha(unichar_id) &&
!getUnicharset().get_isdigit(unichar_id)) {
return false; // neither punc, nor alpha, nor digit
} else if ((new_len = new_word.length()) == 0 ||
new_word.unichar_id(new_len-1) != Dawg::kPatternUnicharID) {
new_word.append_unichar_id(Dawg::kPatternUnicharID, 1, 0.0, 0.0);
}
}
for (i = 0; i < dawgs_.size(); ++i) {
if (dawgs_[i] != NULL &&
dawgs_[i]->type() == DAWG_TYPE_PUNCTUATION &&
dawgs_[i]->word_in_dawg(new_word)) return true;
}
return false;
}
// Returns the "dominant" script ID for the word. By "dominant", the script
// must account for at least half the characters. Otherwise, it returns 0.
// Note that for Japanese, Hiragana and Katakana are simply treated as Han.
int Dict::get_top_word_script(const BLOB_CHOICE_LIST_VECTOR &char_choices,
const UNICHARSET &unicharset) {
int max_script = unicharset.get_script_table_size();
int *sid = new int[max_script];
int x;
for (x = 0; x < max_script; x++) sid[x] = 0;
for (x = 0; x < char_choices.length(); ++x) {
BLOB_CHOICE_IT blob_choice_it(char_choices.get(x));
sid[blob_choice_it.data()->script_id()]++;
}
if (unicharset.han_sid() != unicharset.null_sid()) {
// Add the Hiragana & Katakana counts to Han and zero them out.
if (unicharset.hiragana_sid() != unicharset.null_sid()) {
sid[unicharset.han_sid()] += sid[unicharset.hiragana_sid()];
sid[unicharset.hiragana_sid()] = 0;
}
if (unicharset.katakana_sid() != unicharset.null_sid()) {
sid[unicharset.han_sid()] += sid[unicharset.katakana_sid()];
sid[unicharset.katakana_sid()] = 0;
}
}
// Note that high script ID overrides lower one on a tie, thus biasing
// towards non-Common script (if sorted that way in unicharset file).
int max_sid = 0;
for (x = 1; x < max_script; x++)
if (sid[x] >= sid[max_sid]) max_sid = x;
if (sid[max_sid] < char_choices.length() / 2)
max_sid = unicharset.null_sid();
delete[] sid;
return max_sid;
}
} // namespace tesseract
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