tesseract  5.0.0
workingpartset.cpp
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1 // File: workingpartset.cpp
3 // Description: Class to hold a working set of partitions of the page
4 // during construction of text/image regions.
5 // Author: Ray Smith
6 // Created: Tue Ocr 28 17:21:01 PDT 2008
7 //
8 // (C) Copyright 2008, Google Inc.
9 // Licensed under the Apache License, Version 2.0 (the "License");
10 // you may not use this file except in compliance with the License.
11 // You may obtain a copy of the License at
12 // http://www.apache.org/licenses/LICENSE-2.0
13 // Unless required by applicable law or agreed to in writing, software
14 // distributed under the License is distributed on an "AS IS" BASIS,
15 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 // See the License for the specific language governing permissions and
17 // limitations under the License.
18 //
20 
21 #include "workingpartset.h"
22 #include "colpartition.h"
23 
24 namespace tesseract {
25 
26 // Add the partition to this WorkingPartSet. Unrelated partitions are
27 // stored in the order in which they are received, but if the partition
28 // has a SingletonPartner, make sure that it stays with its partner.
30  ColPartition *partner = part->SingletonPartner(true);
31  if (partner != nullptr) {
32  ASSERT_HOST(partner->SingletonPartner(false) == part);
33  }
34  if (latest_part_ == nullptr || partner == nullptr) {
35  // This partition goes at the end of the list
36  part_it_.move_to_last();
37  } else if (latest_part_->SingletonPartner(false) != part) {
38  // Reposition the iterator to the correct partner, or at the end.
39  for (part_it_.move_to_first(); !part_it_.at_last() && part_it_.data() != partner;
40  part_it_.forward()) {
41  ;
42  }
43  }
44  part_it_.add_after_then_move(part);
45  latest_part_ = part;
46 }
47 
48 // Make blocks out of any partitions in this WorkingPartSet, and append
49 // them to the end of the blocks list. bleft, tright and resolution give
50 // the bounds and resolution of the source image, so that blocks can be
51 // made to fit in the bounds.
52 // All ColPartitions go in the used_parts list, as they need to be kept
53 // around, but are no longer needed.
54 void WorkingPartSet::ExtractCompletedBlocks(const ICOORD &bleft, const ICOORD &tright,
55  int resolution, ColPartition_LIST *used_parts,
56  BLOCK_LIST *blocks, TO_BLOCK_LIST *to_blocks) {
57  MakeBlocks(bleft, tright, resolution, used_parts);
58  BLOCK_IT block_it(blocks);
59  block_it.move_to_last();
60  block_it.add_list_after(&completed_blocks_);
61  TO_BLOCK_IT to_block_it(to_blocks);
62  to_block_it.move_to_last();
63  to_block_it.add_list_after(&to_blocks_);
64 }
65 
66 // Insert the given blocks at the front of the completed_blocks_ list so
67 // they can be kept in the correct reading order.
68 void WorkingPartSet::InsertCompletedBlocks(BLOCK_LIST *blocks, TO_BLOCK_LIST *to_blocks) {
69  BLOCK_IT block_it(&completed_blocks_);
70  block_it.add_list_before(blocks);
71  TO_BLOCK_IT to_block_it(&to_blocks_);
72  to_block_it.add_list_before(to_blocks);
73 }
74 
75 // Make a block using lines parallel to the given vector that fit between
76 // the min and max coordinates specified by the ColPartitions.
77 // Construct a block from the given list of partitions.
78 void WorkingPartSet::MakeBlocks(const ICOORD &bleft, const ICOORD &tright, int resolution,
79  ColPartition_LIST *used_parts) {
80  part_it_.move_to_first();
81  while (!part_it_.empty()) {
82  // Gather a list of ColPartitions in block_parts that will be split
83  // by linespacing into smaller blocks.
84  ColPartition_LIST block_parts;
85  ColPartition_IT block_it(&block_parts);
86  ColPartition *next_part = nullptr;
87  bool text_block = false;
88  do {
89  ColPartition *part = part_it_.extract();
90  if (part->blob_type() == BRT_UNKNOWN || (part->IsTextType() && part->type() != PT_TABLE)) {
91  text_block = true;
92  }
93  part->set_working_set(nullptr);
94  part_it_.forward();
95  block_it.add_after_then_move(part);
96  next_part = part->SingletonPartner(false);
97  if (part_it_.empty() || next_part != part_it_.data()) {
98  // Sequences of partitions can get split by titles.
99  next_part = nullptr;
100  }
101  // Merge adjacent blocks that are of the same type and let the
102  // linespacing determine the real boundaries.
103  if (next_part == nullptr && !part_it_.empty()) {
104  ColPartition *next_block_part = part_it_.data();
105  const TBOX &part_box = part->bounding_box();
106  const TBOX &next_box = next_block_part->bounding_box();
107 
108  // In addition to the same type, the next box must not be above the
109  // current box, nor (if image) too far below.
110  PolyBlockType type = part->type(), next_type = next_block_part->type();
111  if (ColPartition::TypesSimilar(type, next_type) && !part->IsLineType() &&
112  !next_block_part->IsLineType() && next_box.bottom() <= part_box.top() &&
113  (text_block || part_box.bottom() <= next_box.top())) {
114  next_part = next_block_part;
115  }
116  }
117  } while (!part_it_.empty() && next_part != nullptr);
118  if (!text_block) {
119  TO_BLOCK *to_block = ColPartition::MakeBlock(bleft, tright, &block_parts, used_parts);
120  if (to_block != nullptr) {
121  TO_BLOCK_IT to_block_it(&to_blocks_);
122  to_block_it.add_to_end(to_block);
123  BLOCK_IT block_it(&completed_blocks_);
124  block_it.add_to_end(to_block->block);
125  }
126  } else {
127  // Further sub-divide text blocks where linespacing changes.
128  ColPartition::LineSpacingBlocks(bleft, tright, resolution, &block_parts, used_parts,
129  &completed_blocks_, &to_blocks_);
130  }
131  }
132  part_it_.set_to_list(&part_set_);
133  latest_part_ = nullptr;
134  ASSERT_HOST(completed_blocks_.length() == to_blocks_.length());
135 }
136 
137 } // namespace tesseract.
#define ASSERT_HOST(x)
Definition: errcode.h:59
@ TBOX
@ BRT_UNKNOWN
Definition: blobbox.h:80
integer coordinate
Definition: points.h:36
static void LineSpacingBlocks(const ICOORD &bleft, const ICOORD &tright, int resolution, ColPartition_LIST *block_parts, ColPartition_LIST *used_parts, BLOCK_LIST *completed_blocks, TO_BLOCK_LIST *to_blocks)
static TO_BLOCK * MakeBlock(const ICOORD &bleft, const ICOORD &tright, ColPartition_LIST *block_parts, ColPartition_LIST *used_parts)
PolyBlockType type() const
Definition: colpartition.h:180
void set_working_set(WorkingPartSet *working_set)
Definition: colpartition.h:201
BlobRegionType blob_type() const
Definition: colpartition.h:147
static bool TypesSimilar(PolyBlockType type1, PolyBlockType type2)
Definition: colpartition.h:418
ColPartition * SingletonPartner(bool upper)
const TBOX & bounding_box() const
Definition: colpartition.h:108
void AddPartition(ColPartition *part)
void ExtractCompletedBlocks(const ICOORD &bleft, const ICOORD &tright, int resolution, ColPartition_LIST *used_parts, BLOCK_LIST *blocks, TO_BLOCK_LIST *to_blocks)
void InsertCompletedBlocks(BLOCK_LIST *blocks, TO_BLOCK_LIST *to_blocks)