diff options
Diffstat (limited to 'tesseract/src/textord/workingpartset.cpp')
| -rw-r--r-- | tesseract/src/textord/workingpartset.cpp | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/tesseract/src/textord/workingpartset.cpp b/tesseract/src/textord/workingpartset.cpp new file mode 100644 index 00000000..97ce70ae --- /dev/null +++ b/tesseract/src/textord/workingpartset.cpp @@ -0,0 +1,144 @@ +/////////////////////////////////////////////////////////////////////// +// File: workingpartset.cpp +// Description: Class to hold a working set of partitions of the page +// during construction of text/image regions. +// Author: Ray Smith +// Created: Tue Ocr 28 17:21:01 PDT 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. +// +/////////////////////////////////////////////////////////////////////// + +#include "workingpartset.h" +#include "colpartition.h" + +namespace tesseract { + +ELISTIZE(WorkingPartSet) + +// Add the partition to this WorkingPartSet. Unrelated partitions are +// stored in the order in which they are received, but if the partition +// has a SingletonPartner, make sure that it stays with its partner. +void WorkingPartSet::AddPartition(ColPartition* part) { + ColPartition* partner = part->SingletonPartner(true); + if (partner != nullptr) { + ASSERT_HOST(partner->SingletonPartner(false) == part); + } + if (latest_part_ == nullptr || partner == nullptr) { + // This partition goes at the end of the list + part_it_.move_to_last(); + } else if (latest_part_->SingletonPartner(false) != part) { + // Reposition the iterator to the correct partner, or at the end. + for (part_it_.move_to_first(); !part_it_.at_last() && + part_it_.data() != partner; + part_it_.forward()); + } + part_it_.add_after_then_move(part); + latest_part_ = part; +} + +// Make blocks out of any partitions in this WorkingPartSet, and append +// them to the end of the blocks list. bleft, tright and resolution give +// the bounds and resolution of the source image, so that blocks can be +// made to fit in the bounds. +// All ColPartitions go in the used_parts list, as they need to be kept +// around, but are no longer needed. +void WorkingPartSet::ExtractCompletedBlocks(const ICOORD& bleft, + const ICOORD& tright, + int resolution, + ColPartition_LIST* used_parts, + BLOCK_LIST* blocks, + TO_BLOCK_LIST* to_blocks) { + MakeBlocks(bleft, tright, resolution, used_parts); + BLOCK_IT block_it(blocks); + block_it.move_to_last(); + block_it.add_list_after(&completed_blocks_); + TO_BLOCK_IT to_block_it(to_blocks); + to_block_it.move_to_last(); + to_block_it.add_list_after(&to_blocks_); +} + +// Insert the given blocks at the front of the completed_blocks_ list so +// they can be kept in the correct reading order. +void WorkingPartSet::InsertCompletedBlocks(BLOCK_LIST* blocks, + TO_BLOCK_LIST* to_blocks) { + BLOCK_IT block_it(&completed_blocks_); + block_it.add_list_before(blocks); + TO_BLOCK_IT to_block_it(&to_blocks_); + to_block_it.add_list_before(to_blocks); +} + +// Make a block using lines parallel to the given vector that fit between +// the min and max coordinates specified by the ColPartitions. +// Construct a block from the given list of partitions. +void WorkingPartSet::MakeBlocks(const ICOORD& bleft, const ICOORD& tright, + int resolution, ColPartition_LIST* used_parts) { + part_it_.move_to_first(); + while (!part_it_.empty()) { + // Gather a list of ColPartitions in block_parts that will be split + // by linespacing into smaller blocks. + ColPartition_LIST block_parts; + ColPartition_IT block_it(&block_parts); + ColPartition* next_part = nullptr; + bool text_block = false; + do { + ColPartition* part = part_it_.extract(); + if (part->blob_type() == BRT_UNKNOWN || + (part->IsTextType() && part->type() != PT_TABLE)) + text_block = true; + part->set_working_set(nullptr); + part_it_.forward(); + block_it.add_after_then_move(part); + next_part = part->SingletonPartner(false); + if (part_it_.empty() || next_part != part_it_.data()) { + // Sequences of partitions can get split by titles. + next_part = nullptr; + } + // Merge adjacent blocks that are of the same type and let the + // linespacing determine the real boundaries. + if (next_part == nullptr && !part_it_.empty()) { + ColPartition* next_block_part = part_it_.data(); + const TBOX& part_box = part->bounding_box(); + const TBOX& next_box = next_block_part->bounding_box(); + + // In addition to the same type, the next box must not be above the + // current box, nor (if image) too far below. + PolyBlockType type = part->type(), next_type = next_block_part->type(); + if (ColPartition::TypesSimilar(type, next_type) && + !part->IsLineType() && !next_block_part->IsLineType() && + next_box.bottom() <= part_box.top() && + (text_block || part_box.bottom() <= next_box.top())) + next_part = next_block_part; + } + } while (!part_it_.empty() && next_part != nullptr); + if (!text_block) { + TO_BLOCK* to_block = ColPartition::MakeBlock(bleft, tright, + &block_parts, used_parts); + if (to_block != nullptr) { + TO_BLOCK_IT to_block_it(&to_blocks_); + to_block_it.add_to_end(to_block); + BLOCK_IT block_it(&completed_blocks_); + block_it.add_to_end(to_block->block); + } + } else { + // Further sub-divide text blocks where linespacing changes. + ColPartition::LineSpacingBlocks(bleft, tright, resolution, &block_parts, + used_parts, + &completed_blocks_, &to_blocks_); + } + } + part_it_.set_to_list(&part_set_); + latest_part_ = nullptr; + ASSERT_HOST(completed_blocks_.length() == to_blocks_.length()); +} + +} // namespace tesseract. |