/////////////////////////////////////////////////////////////////////// // File: colpartition.cpp // Description: Class to hold partitions of the page that correspond // roughly to text lines. // Author: Ray Smith // Created: Thu Aug 14 10:54:01 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 "colpartition.h" #include "colpartitionset.h" #include "workingpartset.h" #ifdef _MSC_VER #pragma warning(disable:4244) // Conversion warnings #endif namespace tesseract { ELIST2IZE(ColPartition) CLISTIZE(ColPartition) //////////////// ColPartition Implementation //////////////// // If multiple partners survive the partner depth test beyond this level, // then arbitrarily pick one. const int kMaxPartnerDepth = 4; // Maximum change in spacing (in inches) to ignore. const double kMaxSpacingDrift = 1.0 / 72; // 1/72 is one point. // Maximum fraction of line height used as an additional allowance // for top spacing. const double kMaxTopSpacingFraction = 0.25; // Maximum ratio of sizes for lines to be considered the same size. const double kMaxSizeRatio = 1.5; // blob_type is the blob_region_type_ of the blobs in this partition. // Vertical is the direction of logical vertical on the possibly skewed image. ColPartition::ColPartition(BlobRegionType blob_type, const ICOORD& vertical) : left_margin_(MIN_INT32), right_margin_(MAX_INT32), median_bottom_(MAX_INT32), median_top_(MIN_INT32), median_size_(0), blob_type_(blob_type), good_width_(false), good_column_(false), left_key_tab_(false), right_key_tab_(false), left_key_(0), right_key_(0), type_(PT_UNKNOWN), vertical_(vertical), working_set_(NULL), block_owned_(false), first_column_(-1), last_column_(-1), column_set_(NULL), side_step_(0), top_spacing_(0), bottom_spacing_(0), type_before_table_(PT_UNKNOWN), inside_table_column_(false), nearest_neighbor_above_(NULL), nearest_neighbor_below_(NULL), space_above_(0), space_below_(0), space_to_left_(0), space_to_right_(0) { } // Constructs a fake ColPartition with a single fake BLOBNBOX, all made // from a single TBOX. // WARNING: Despite being on C_LISTs, the BLOBNBOX owns the C_BLOB and // the ColPartition owns the BLOBNBOX!!! // Call DeleteBoxes before deleting the ColPartition. ColPartition* ColPartition::FakePartition(const TBOX& box) { ColPartition* part = new ColPartition(BRT_UNKNOWN, ICOORD(0, 1)); part->AddBox(new BLOBNBOX(C_BLOB::FakeBlob(box))); part->set_left_margin(box.left()); part->set_right_margin(box.right()); part->ComputeLimits(); return part; } ColPartition::~ColPartition() { // Remove this as a partner of all partners, as we don't want them // referring to a deleted object. ColPartition_C_IT it(&upper_partners_); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { it.data()->RemovePartner(false, this); } it.set_to_list(&lower_partners_); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { it.data()->RemovePartner(true, this); } } // Constructs a fake ColPartition with no BLOBNBOXes. // Used for making horizontal line ColPartitions and types it accordingly. ColPartition::ColPartition(const ICOORD& vertical, int left, int bottom, int right, int top) : left_margin_(MIN_INT32), right_margin_(MAX_INT32), bounding_box_(left, bottom, right, top), median_bottom_(bottom), median_top_(top), median_size_(top - bottom), blob_type_(BRT_HLINE), good_width_(false), good_column_(false), left_key_tab_(false), right_key_tab_(false), type_(PT_UNKNOWN), vertical_(vertical), working_set_(NULL), block_owned_(false), first_column_(-1), last_column_(-1), column_set_(NULL), side_step_(0), top_spacing_(0), bottom_spacing_(0), type_before_table_(PT_UNKNOWN), inside_table_column_(false), nearest_neighbor_above_(NULL), nearest_neighbor_below_(NULL), space_above_(0), space_below_(0), space_to_left_(0), space_to_right_(0) { left_key_ = BoxLeftKey(); right_key_ = BoxRightKey(); } // Adds the given box to the partition, updating the partition bounds. // The list of boxes in the partition is updated, ensuring that no box is // recorded twice, and the boxes are kept in increasing left position. void ColPartition::AddBox(BLOBNBOX* bbox) { boxes_.add_sorted(SortByBoxLeft, true, bbox); TBOX box = bbox->bounding_box(); // Update the partition limits. bounding_box_ += box; if (!left_key_tab_) left_key_ = BoxLeftKey(); if (!right_key_tab_) right_key_ = BoxRightKey(); if (TabFind::WithinTestRegion(2, box.left(), box.bottom())) tprintf("Added box (%d,%d)->(%d,%d) left_blob_x_=%d, right_blob_x_ = %d\n", box.left(), box.bottom(), box.right(), box.top(), bounding_box_.left(), bounding_box_.right()); } // Claims the boxes in the boxes_list by marking them with a this owner // pointer. If a box is already owned, then run Unique on it. void ColPartition::ClaimBoxes(WidthCallback* cb) { bool completed = true; do { completed = true; BLOBNBOX_C_IT bb_it(&boxes_); for (bb_it.mark_cycle_pt(); !bb_it.cycled_list(); bb_it.forward()) { BLOBNBOX* bblob = bb_it.data(); ColPartition* other = bblob->owner(); if (other == NULL) { // Normal case: ownership is available. bblob->set_owner(this); } else if (other != this) { // bblob already has an owner, so resolve the dispute with Unique. // Null everything owned by this upto, but not including bblob, as // they will all be up for grabs in Unique. for (bb_it.move_to_first(); bb_it.data() != bblob; bb_it.forward()) { ASSERT_HOST(bb_it.data()->owner() == this); bb_it.data()->set_owner(NULL); } // Null the owners of all other's blobs. They should all be // still owned by other. BLOBNBOX_C_IT other_it(&other->boxes_); for (other_it.mark_cycle_pt(); !other_it.cycled_list(); other_it.forward()) { ASSERT_HOST(other_it.data()->owner() == other); other_it.data()->set_owner(NULL); } Unique(other, cb); // Now we need to run ClaimBoxes on other, as it may have obtained // a box from this (beyond bbox) that is owned by a third party. other->ClaimBoxes(cb); // Scan our own list for bblob. If bblob is still in it and owned by // other, there is trouble. Otherwise we can just restart to finish // the blob list. bb_it.set_to_list(&boxes_); for (bb_it.mark_cycle_pt(); !bb_it.cycled_list() && bb_it.data() != bblob; bb_it.forward()); ASSERT_HOST(bb_it.cycled_list() || bblob->owner() == NULL); completed = false; break; } } } while (!completed); } // Delete the boxes that this partition owns. void ColPartition::DeleteBoxes() { // Although the boxes_ list is a C_LIST, in some cases it owns the // BLOBNBOXes, as the ColPartition takes ownership from the grid, // and the BLOBNBOXes own the underlying C_BLOBs. for (BLOBNBOX_C_IT bb_it(&boxes_); !bb_it.empty(); bb_it.forward()) { BLOBNBOX* bblob = bb_it.extract(); delete bblob->cblob(); delete bblob; } } // Returns true if this is a legal partition - meaning that the conditions // left_margin <= bounding_box left // left_key <= bounding box left key // bounding box left <= bounding box right // and likewise for right margin and key // are all met. bool ColPartition::IsLegal() { if (bounding_box_.left() > bounding_box_.right()) { if (textord_debug_bugs) { tprintf("Bounding box invalid\n"); Print(); } return false; // Bounding box invalid. } if (left_margin_ > bounding_box_.left() || right_margin_ < bounding_box_.right()) { if (textord_debug_bugs) { tprintf("Margins invalid\n"); Print(); } return false; // Margins invalid. } if (left_key_ > BoxLeftKey() || right_key_ < BoxRightKey()) { if (textord_debug_bugs) { tprintf("Key inside box: %d v %d or %d v %d\n", left_key_, BoxLeftKey(), right_key_, BoxRightKey()); Print(); } return false; // Keys inside the box. } return true; } // Returns true if the left and right edges are approximately equal. bool ColPartition::MatchingColumns(const ColPartition& other) const { int y = (MidY() + other.MidY()) / 2; if (!NearlyEqual(other.LeftAtY(y) / kColumnWidthFactor, LeftAtY(y) / kColumnWidthFactor, 1)) return false; if (!NearlyEqual(other.RightAtY(y) / kColumnWidthFactor, RightAtY(y) / kColumnWidthFactor, 1)) return false; return true; } // Sets the sort key using either the tab vector, or the bounding box if // the tab vector is NULL. If the tab_vector lies inside the bounding_box, // use the edge of the box as a key any way. void ColPartition::SetLeftTab(const TabVector* tab_vector) { if (tab_vector != NULL) { left_key_ = tab_vector->sort_key(); left_key_tab_ = left_key_ <= BoxLeftKey(); } else { left_key_tab_ = false; } if (!left_key_tab_) left_key_ = BoxLeftKey(); } // As SetLeftTab, but with the right. void ColPartition::SetRightTab(const TabVector* tab_vector) { if (tab_vector != NULL) { right_key_ = tab_vector->sort_key(); right_key_tab_ = right_key_ >= BoxRightKey(); } else { right_key_tab_ = false; } if (!right_key_tab_) right_key_ = BoxRightKey(); } // Copies the left/right tab from the src partition, but if take_box is // true, copies the box instead and uses that as a key. void ColPartition::CopyLeftTab(const ColPartition& src, bool take_box) { left_key_tab_ = take_box ? false : src.left_key_tab_; if (left_key_tab_) { left_key_ = src.left_key_; } else { bounding_box_.set_left(XAtY(src.BoxLeftKey(), MidY())); left_key_ = BoxLeftKey(); } if (left_margin_ > bounding_box_.left()) left_margin_ = src.left_margin_; } // As CopyLeftTab, but with the right. void ColPartition::CopyRightTab(const ColPartition& src, bool take_box) { right_key_tab_ = take_box ? false : src.right_key_tab_; if (right_key_tab_) { right_key_ = src.right_key_; } else { bounding_box_.set_right(XAtY(src.BoxRightKey(), MidY())); right_key_ = BoxRightKey(); } if (right_margin_ < bounding_box_.right()) right_margin_ = src.right_margin_; } // Add a partner above if upper, otherwise below. // Add them uniquely and keep the list sorted by box left. // Partnerships are added symmetrically to partner and this. void ColPartition::AddPartner(bool upper, ColPartition* partner) { if (upper) { partner->lower_partners_.add_sorted(SortByBoxLeft, true, this); upper_partners_.add_sorted(SortByBoxLeft, true, partner); } else { partner->upper_partners_.add_sorted(SortByBoxLeft, true, this); lower_partners_.add_sorted(SortByBoxLeft, true, partner); } } // Removes the partner from this, but does not remove this from partner. // This asymmetric removal is so as not to mess up the iterator that is // working on partner's partner list. void ColPartition::RemovePartner(bool upper, ColPartition* partner) { ColPartition_C_IT it(upper ? &upper_partners_ : &lower_partners_); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { if (it.data() == partner) { it.extract(); break; } } } // Returns the partner if the given partner is a singleton, otherwise NULL. ColPartition* ColPartition::SingletonPartner(bool upper) { ColPartition_CLIST* partners = upper ? &upper_partners_ : &lower_partners_; if (!partners->singleton()) return NULL; ColPartition_C_IT it(partners); return it.data(); } // Merge with the other partition and delete it. void ColPartition::Absorb(ColPartition* other, WidthCallback* cb) { if (TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom()) || TabFind::WithinTestRegion(2, other->bounding_box_.left(), other->bounding_box_.bottom())) { tprintf("Merging:"); Print(); other->Print(); } // Merge the two sorted lists. BLOBNBOX_C_IT it(&boxes_); BLOBNBOX_C_IT it2(&other->boxes_); for (; !it2.empty(); it2.forward()) { BLOBNBOX* bbox2 = it2.extract(); ColPartition* prev_owner = bbox2->owner(); ASSERT_HOST(prev_owner == other || prev_owner == NULL); if (prev_owner == other) bbox2->set_owner(this); bbox2->set_region_type(blob_type_); TBOX box2 = bbox2->bounding_box(); int left2 = box2.left(); while (!it.at_last() && it.data()->bounding_box().left() <= left2) { if (it.data() == bbox2) break; it.forward(); } if (!it.empty() && it.data() == bbox2) continue; if (it.empty() || (it.at_last() && it.data()->bounding_box().left() <= left2)) { it.add_after_then_move(bbox2); } else { it.add_before_then_move(bbox2); } } left_margin_ = MIN(left_margin_, other->left_margin_); right_margin_ = MAX(right_margin_, other->right_margin_); if (other->left_key_ < left_key_) { left_key_ = other->left_key_; left_key_tab_ = other->left_key_tab_; } if (other->right_key_ > right_key_) { right_key_ = other->right_key_; right_key_tab_ = other->right_key_tab_; } delete other; ComputeLimits(); if (cb != NULL) { SetColumnGoodness(cb); } } // Shares out any common boxes amongst the partitions, ensuring that no // box stays in both. Returns true if anything was done. bool ColPartition::Unique(ColPartition* other, WidthCallback* cb) { bool debug = TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom()) || TabFind::WithinTestRegion(2, other->bounding_box_.left(), other->bounding_box_.bottom()); if (debug) { tprintf("Running Unique:"); Print(); other->Print(); } BLOBNBOX_C_IT it(&boxes_); BLOBNBOX_C_IT it2(&other->boxes_); it.mark_cycle_pt(); it2.mark_cycle_pt(); bool any_moved = false; while (!it.cycled_list() && !it2.cycled_list()) { BLOBNBOX* bbox = it.data(); BLOBNBOX* bbox2 = it2.data(); TBOX box = bbox->bounding_box(); TBOX box2 = bbox2->bounding_box(); if (box.left() < box2.left()) { it.forward(); } else if (box.left() > box2.left()) { it2.forward(); } else if (bbox == bbox2) { // Separate out most frequent case for efficiency. if (debug) { tprintf("Keeping box (%d,%d)->(%d,%d) only in %s\n", box.left(), box.bottom(), box.right(), box.top(), ThisPartitionBetter(bbox, *other) ? "This" : "Other"); } if (ThisPartitionBetter(bbox, *other)) it2.extract(); else it.extract(); it.forward(); it2.forward(); any_moved = true; } else { // Lefts are equal, but boxes may be in any order. BLOBNBOX_C_IT search_it(it2); for (search_it.forward(); !search_it.at_first() && search_it.data() != bbox && search_it.data()->bounding_box().left() == box.left(); search_it.forward()); if (search_it.data() == bbox) { // Found a match. if (ThisPartitionBetter(bbox, *other)) { search_it.extract(); // We just (potentially) invalidated it2, so reposition at bbox2. it2.move_to_first(); for (it2.mark_cycle_pt(); it2.data() != bbox2; it2.forward()); } else { it.extract(); } it.forward(); any_moved = true; } else { // No match to bbox in list2. Just move first it forward. it.forward(); } } } // Now check to see if there are any in either list that would be better // off in the other. if (!it.empty()) { it.move_to_first(); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { BLOBNBOX* bbox = it.data(); if (!ThisPartitionBetter(bbox, *other)) { other->AddBox(it.extract()); TBOX box = bbox->bounding_box(); if (debug) { tprintf("Moved box (%d,%d)->(%d,%d) from this to other:\n", box.left(), box.bottom(), box.right(), box.top()); } any_moved = true; } } } if (!it2.empty()) { it2.move_to_first(); for (it2.mark_cycle_pt(); !it2.cycled_list(); it2.forward()) { BLOBNBOX* bbox2 = it2.data(); if (ThisPartitionBetter(bbox2, *other)) { AddBox(it2.extract()); TBOX box = bbox2->bounding_box(); if (debug) { tprintf("Moved box (%d,%d)->(%d,%d) from other to this:\n", box.left(), box.bottom(), box.right(), box.top()); } any_moved = true; } } } if (any_moved) { if (debug) tprintf("Unique did something!\n"); ComputeLimits(); other->ComputeLimits(); if (cb != NULL) { SetColumnGoodness(cb); other->SetColumnGoodness(cb); } } return any_moved; } // Split this partition at the given x coordinate, returning the right // half and keeping the left half in this. ColPartition* ColPartition::SplitAt(int split_x) { if (split_x <= bounding_box_.left() || split_x >= bounding_box_.right()) return NULL; // There will be no change. ColPartition* split_part = ShallowCopy(); BLOBNBOX_C_IT it(&boxes_); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { BLOBNBOX* bbox = it.data(); ColPartition* prev_owner = bbox->owner(); ASSERT_HOST(prev_owner == this || prev_owner == NULL); const TBOX& box = bbox->bounding_box(); if (box.left() >= split_x) { split_part->AddBox(it.extract()); if (prev_owner != NULL) bbox->set_owner(split_part); } } ASSERT_HOST(!it.empty()); if (split_part->IsEmpty()) { // Split part ended up with nothing. Possible if split_x passes // through the last blob. delete split_part; return NULL; } right_key_tab_ = false; split_part->left_key_tab_ = false; right_margin_ = split_x; split_part->left_margin_ = split_x; ComputeLimits(); split_part->ComputeLimits(); return split_part; } // Recalculates all the coordinate limits of the partition. void ColPartition::ComputeLimits() { bounding_box_ = TBOX(); // Clear it BLOBNBOX_C_IT it(&boxes_); BLOBNBOX* bbox = NULL; if (it.empty()) { bounding_box_.set_left(left_margin_); bounding_box_.set_right(right_margin_); bounding_box_.set_bottom(0); bounding_box_.set_top(0); } else { for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { bbox = it.data(); bounding_box_ += bbox->bounding_box(); } } if (!left_key_tab_) left_key_ = BoxLeftKey(); if (left_key_ > BoxLeftKey() && textord_debug_bugs) { // TODO(rays) investigate the causes of these error messages, to find // out if they are genuinely harmful, or just indicative of junk input. tprintf("Computed left-illegal partition\n"); Print(); } if (!right_key_tab_) right_key_ = BoxRightKey(); if (right_key_ < BoxRightKey() && textord_debug_bugs) { tprintf("Computed right-illegal partition\n"); Print(); } if (it.empty()) return; STATS top_stats(bounding_box_.bottom(), bounding_box_.top() + 1); STATS bottom_stats(bounding_box_.bottom(), bounding_box_.top() + 1); STATS size_stats(0, bounding_box_.height() + 1); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { bbox = it.data(); TBOX box = bbox->bounding_box(); top_stats.add(box.top(), 1); bottom_stats.add(box.bottom(), 1); size_stats.add(box.height(), 1); } median_top_ = static_cast(top_stats.median() + 0.5); median_bottom_ = static_cast(bottom_stats.median() + 0.5); median_size_ = static_cast(size_stats.median() + 0.5); if (right_margin_ < bounding_box_.right() && textord_debug_bugs) { tprintf("Made partition with bad right coords"); Print(); } if (left_margin_ > bounding_box_.left() && textord_debug_bugs) { tprintf("Made partition with bad left coords"); Print(); } if (TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom())) { tprintf("Recomputed box for partition %p\n", this); Print(); } } // Computes and sets the type_ and first_colum_, last_column_ and column_set_. void ColPartition::SetPartitionType(ColPartitionSet* columns) { int first_spanned_col = -1; int last_spanned_col = -1; type_ = columns->SpanningType(blob_type_, bounding_box_.left(), bounding_box_.right(), MidY(), left_margin_, right_margin_, &first_column_, &last_column_, &first_spanned_col, &last_spanned_col); column_set_ = columns; if (first_column_ != last_column_ && (type_ == PT_PULLOUT_TEXT || type_ == PT_PULLOUT_IMAGE || type_ == PT_PULLOUT_LINE)) { // Unequal columns may indicate that the pullout spans one of the columns // it lies in, so force it to be allocated to just that column. if (first_spanned_col >= 0) { first_column_ = first_spanned_col; last_column_ = first_spanned_col; } else { if ((first_column_ & 1) == 0) last_column_ = first_column_; else if ((last_column_ & 1) == 0) first_column_ = last_column_; else first_column_ = last_column_ = (first_column_ + last_column_) / 2; } } } // Returns the first and last column touched by this partition. void ColPartition::ColumnRange(ColPartitionSet* columns, int* first_col, int* last_col) { int first_spanned_col = -1; int last_spanned_col = -1; type_ = columns->SpanningType(blob_type_, bounding_box_.left(), bounding_box_.right(), MidY(), left_margin_, right_margin_, first_col, last_col, &first_spanned_col, &last_spanned_col); } // Sets the internal flags good_width_ and good_column_. void ColPartition::SetColumnGoodness(WidthCallback* cb) { int y = MidY(); int width = RightAtY(y) - LeftAtY(y); good_width_ = cb->Run(width); good_column_ = blob_type_ == BRT_TEXT && left_key_tab_ && right_key_tab_; } // Adds this ColPartition to a matching WorkingPartSet if one can be found, // otherwise starts a new one in the appropriate column, ending the previous. void ColPartition::AddToWorkingSet(const ICOORD& bleft, const ICOORD& tright, int resolution, ColPartition_LIST* used_parts, WorkingPartSet_LIST* working_sets) { if (block_owned_) return; // Done it already. block_owned_ = true; WorkingPartSet_IT it(working_sets); // If there is an upper partner use its working_set_ directly. ColPartition* partner = SingletonPartner(true); if (partner != NULL && partner->working_set_ != NULL) { working_set_ = partner->working_set_; working_set_->AddPartition(this); return; } if (partner != NULL && textord_debug_bugs) { tprintf("Partition with partner has no working set!:"); Print(); partner->Print(); } // Search for the column that the left edge fits in. WorkingPartSet* work_set = NULL; it.move_to_first(); int col_index = 0; for (it.mark_cycle_pt(); !it.cycled_list() && col_index != first_column_; it.forward(), ++col_index); if (textord_debug_tabfind >= 2) { tprintf("Match is %s for:", (col_index & 1) ? "Real" : "Between"); Print(); } if (it.cycled_list() && textord_debug_bugs) { tprintf("Target column=%d, only had %d\n", first_column_, col_index); } ASSERT_HOST(!it.cycled_list()); work_set = it.data(); // If last_column_ != first_column, then we need to scoop up all blocks // between here and the last_column_ and put back in work_set. if (!it.cycled_list() && last_column_ != first_column_) { // Find the column that the right edge falls in. BLOCK_LIST completed_blocks; TO_BLOCK_LIST to_blocks; for (; !it.cycled_list() && col_index <= last_column_; it.forward(), ++col_index) { WorkingPartSet* end_set = it.data(); end_set->ExtractCompletedBlocks(bleft, tright, resolution, used_parts, &completed_blocks, &to_blocks); } work_set->InsertCompletedBlocks(&completed_blocks, &to_blocks); } working_set_ = work_set; work_set->AddPartition(this); } // From the given block_parts list, builds one or more BLOCKs and // corresponding TO_BLOCKs, such that the line spacing is uniform in each. // Created blocks are appended to the end of completed_blocks and to_blocks. // The used partitions are put onto used_parts, as they may still be referred // to in the partition grid. bleft, tright and resolution are the bounds // and resolution of the original image. void ColPartition::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) { int page_height = tright.y() - bleft.y(); // Compute the initial spacing stats. ColPartition_IT it(block_parts); int part_count = 0; for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* part = it.data(); ASSERT_HOST(!part->boxes()->empty()); STATS side_steps(0, part->bounding_box().height()); BLOBNBOX_C_IT blob_it(part->boxes()); int prev_bottom = blob_it.data()->bounding_box().bottom(); for (blob_it.forward(); !blob_it.at_first(); blob_it.forward()) { BLOBNBOX* blob = blob_it.data(); int bottom = blob->bounding_box().bottom(); int step = bottom - prev_bottom; if (step < 0) step = -step; side_steps.add(step, 1); prev_bottom = bottom; } part->set_side_step(static_cast(side_steps.median() + 0.5)); if (!it.at_last()) { ColPartition* next_part = it.data_relative(1); part->set_bottom_spacing(part->median_bottom() - next_part->median_bottom()); part->set_top_spacing(part->median_top() - next_part->median_top()); } else { part->set_bottom_spacing(page_height); part->set_top_spacing(page_height); } if (textord_debug_tabfind) { part->Print(); tprintf("side step = %.2f, top spacing = %d, bottom spacing=%d\n", side_steps.median(), part->top_spacing(), part->bottom_spacing()); } ++part_count; } if (part_count == 0) return; SmoothSpacings(resolution, page_height, block_parts); // Move the partitions into individual block lists and make the blocks. BLOCK_IT block_it(completed_blocks); TO_BLOCK_IT to_block_it(to_blocks); ColPartition_LIST spacing_parts; ColPartition_IT sp_block_it(&spacing_parts); for (it.mark_cycle_pt(); !it.empty();) { ColPartition* part = it.extract(); sp_block_it.add_to_end(part); it.forward(); if (it.empty() || !part->SpacingsEqual(*it.data(), resolution)) { // There is a spacing boundary. Check to see if it.data() belongs // better in the current block or the next one. if (!it.empty()) { ColPartition* next_part = it.data(); // If there is a size match one-way, then the middle line goes with // its matched size, otherwise it goes with the smallest spacing. ColPartition* third_part = it.at_last() ? NULL : it.data_relative(1); if (textord_debug_tabfind) tprintf("Spacings unequal: upper:%d/%d, lower:%d/%d," " sizes %d %d %d\n", part->top_spacing(), part->bottom_spacing(), next_part->top_spacing(), next_part->bottom_spacing(), part->median_size(), next_part->median_size(), third_part != NULL ? third_part->median_size() : 0); // If spacing_diff ends up positive, then next_part goes in the // current block. int spacing_diff = next_part->bottom_spacing() - part->bottom_spacing(); if (part->SizesSimilar(*next_part) && (third_part == NULL || !next_part->SizesSimilar(*third_part))) { // Sizes overrule. spacing_diff = 1; } else if (!part->SizesSimilar(*next_part) && third_part != NULL && next_part->SizesSimilar(*third_part)) { // Sizes overrule. spacing_diff = -1; } if (spacing_diff > 0) { sp_block_it.add_to_end(it.extract()); it.forward(); } } TO_BLOCK* to_block = MakeBlock(bleft, tright, &spacing_parts, used_parts); if (to_block != NULL) { to_block_it.add_to_end(to_block); block_it.add_to_end(to_block->block); } sp_block_it.set_to_list(&spacing_parts); } } } // Helper function to clip the input pos to the given bleft, tright bounds. static void ClipCoord(const ICOORD& bleft, const ICOORD& tright, ICOORD* pos) { if (pos->x() < bleft.x()) pos->set_x(bleft.x()); if (pos->x() > tright.x()) pos->set_x(tright.x()); if (pos->y() < bleft.y()) pos->set_y(bleft.y()); if (pos->y() > tright.y()) pos->set_y(tright.y()); } // Constructs a block from the given list of partitions. // Arguments are as LineSpacingBlocks above. TO_BLOCK* ColPartition::MakeBlock(const ICOORD& bleft, const ICOORD& tright, ColPartition_LIST* block_parts, ColPartition_LIST* used_parts) { if (block_parts->empty()) return NULL; // Nothing to do. ColPartition_IT it(block_parts); ColPartition* part = it.data(); int line_spacing = part->bottom_spacing(); if (line_spacing < part->median_size()) line_spacing = part->bounding_box().height(); PolyBlockType type = it.data()->type(); bool text_type = it.data()->IsTextType(); ICOORDELT_LIST vertices; ICOORDELT_IT vert_it(&vertices); ICOORD start, end; int min_x = MAX_INT32; int max_x = MIN_INT32; int min_y = MAX_INT32; int max_y = MIN_INT32; int iteration = 0; do { if (iteration == 0) ColPartition::LeftEdgeRun(&it, &start, &end); else ColPartition::RightEdgeRun(&it, &start, &end); ClipCoord(bleft, tright, &start); ClipCoord(bleft, tright, &end); vert_it.add_after_then_move(new ICOORDELT(start)); vert_it.add_after_then_move(new ICOORDELT(end)); min_x = MIN(min_x, start.x()); min_x = MIN(min_x, end.x()); max_x = MAX(max_x, start.x()); max_x = MAX(max_x, end.x()); min_y = MIN(min_y, start.y()); min_y = MIN(min_y, end.y()); max_y = MAX(max_y, start.y()); max_y = MAX(max_y, end.y()); if ((iteration == 0 && it.at_first()) || (iteration == 1 && it.at_last())) { ++iteration; it.move_to_last(); } } while (iteration < 2); if (textord_debug_tabfind) tprintf("Making block at (%d,%d)->(%d,%d)\n", min_x, min_y, max_x, max_y); BLOCK* block = new BLOCK("", true, 0, 0, min_x, min_y, max_x, max_y); block->set_poly_block(new POLY_BLOCK(&vertices, type)); // Make a matching TO_BLOCK and put all the BLOBNBOXes from the parts in it. // Move all the parts to a done list as they are no longer needed, except // that have have to continue to exist until the part grid is deleted. // Compute the median blob size as we go, as the block needs to know. STATS heights(0, max_y + 1 - min_y); TO_BLOCK* to_block = new TO_BLOCK(block); BLOBNBOX_IT blob_it(&to_block->blobs); ColPartition_IT used_it(used_parts); for (it.move_to_first(); !it.empty(); it.forward()) { ColPartition* part = it.extract(); if (text_type) { // Only transfer blobs from text regions to the output blocks. // The rest stay behind and get deleted with the ColPartitions. for (BLOBNBOX_C_IT bb_it(part->boxes()); !bb_it.empty(); bb_it.forward()) { BLOBNBOX* bblob = bb_it.extract(); ASSERT_HOST(bblob->owner() == part); ASSERT_HOST(bblob->region_type() >= BRT_UNKNOWN); C_OUTLINE_IT ol_it(bblob->cblob()->out_list()); ASSERT_HOST(ol_it.data()->pathlength() > 0); heights.add(bblob->bounding_box().height(), 1); blob_it.add_after_then_move(bblob); } } used_it.add_to_end(part); } if (text_type && blob_it.empty()) { delete block; delete to_block; return NULL; } to_block->line_size = heights.median(); int block_height = block->bounding_box().height(); if (block_height < line_spacing) line_spacing = block_height; to_block->line_spacing = line_spacing; to_block->max_blob_size = block_height + 1; if (type == PT_VERTICAL_TEXT) { // This block will get rotated 90 deg clockwise so record the inverse. FCOORD rotation(0.0f, 1.0f); block->set_re_rotation(rotation); } return to_block; } // Returns a copy of everything except the list of boxes. The resulting // ColPartition is only suitable for keeping in a column candidate list. ColPartition* ColPartition::ShallowCopy() const { ColPartition* part = new ColPartition(blob_type_, vertical_); part->left_margin_ = left_margin_; part->right_margin_ = right_margin_; part->bounding_box_ = bounding_box_; part->median_bottom_ = median_bottom_; part->median_top_ = median_top_; part->median_size_ = median_size_; part->good_width_ = good_width_; part->good_column_ = good_column_; part->left_key_tab_ = left_key_tab_; part->right_key_tab_ = right_key_tab_; part->type_ = type_; part->left_key_ = left_key_; part->right_key_ = right_key_; return part; } // Provides a color for BBGrid to draw the rectangle. // Must be kept in sync with PolyBlockType. ScrollView::Color ColPartition::BoxColor() const { return POLY_BLOCK::ColorForPolyBlockType(type_); } // Keep in sync with BlobRegionType. static char kBlobTypes[BRT_COUNT + 1] = "NHRIUVT"; // Prints debug information on this. void ColPartition::Print() { int y = MidY(); tprintf("ColPart:%c(M%d-%c%d-B%d,%d/%d)->(%dB-%d%c-%dM,%d/%d)" " w-ok=%d, v-ok=%d, type=%d%c, fc=%d, lc=%d, boxes=%d" " ts=%d bs=%d ls=%d rs=%d\n", boxes_.empty() ? 'E' : ' ', left_margin_, left_key_tab_ ? 'T' : 'B', LeftAtY(y), bounding_box_.left(), median_bottom_, bounding_box_.bottom(), bounding_box_.right(), RightAtY(y), right_key_tab_ ? 'T' : 'B', right_margin_, median_top_, bounding_box_.top(), good_width_, good_column_, type_, kBlobTypes[blob_type_], first_column_, last_column_, boxes_.length(), space_above_, space_below_, space_to_left_, space_to_right_); } // Sets the types of all partitions in the run to be the max of the types. void ColPartition::SmoothPartnerRun(int working_set_count) { STATS left_stats(0, working_set_count); STATS right_stats(0, working_set_count); PolyBlockType max_type = type_; ColPartition* partner; for (partner = SingletonPartner(false); partner != NULL; partner = partner->SingletonPartner(false)) { if (partner->type_ > max_type) max_type = partner->type_; if (column_set_ == partner->column_set_) { left_stats.add(partner->first_column_, 1); right_stats.add(partner->last_column_, 1); } } type_ = max_type; first_column_ = left_stats.mode(); last_column_ = right_stats.mode(); if (last_column_ < first_column_) last_column_ = first_column_; for (partner = SingletonPartner(false); partner != NULL; partner = partner->SingletonPartner(false)) { partner->type_ = max_type; if (column_set_ == partner->column_set_) { partner->first_column_ = first_column_; partner->last_column_ = last_column_; } } } // Cleans up the partners of the given type so that there is at most // one partner. This makes block creation simpler. void ColPartition::RefinePartners(PolyBlockType type) { if (type_ == type) { RefinePartnersInternal(true); RefinePartnersInternal(false); } else if (type == PT_COUNT) { // This is the final pass. Make sure only the correctly typed // partners surivive, however many there are. RefinePartnersByType(true, &upper_partners_); RefinePartnersByType(false, &lower_partners_); } } ////////////////// PRIVATE CODE ///////////////////////////// // Cleans up the partners above if upper is true, else below. void ColPartition::RefinePartnersInternal(bool upper) { ColPartition_CLIST* partners = upper ? &upper_partners_ : &lower_partners_; if (!partners->empty() && !partners->singleton()) { RefinePartnersByType(upper, partners); if (!partners->empty() && !partners->singleton()) { // Check for transitive partnerships and break the cycle. RefinePartnerShortcuts(upper, partners); if (!partners->empty() && !partners->singleton()) { // Types didn't fix it. Flowing text keeps the one with the longest // sequence of singleton matching partners. All others max overlap. if (type_ == PT_FLOWING_TEXT) RefineFlowingTextPartners(upper, partners); else RefinePartnersByOverlap(upper, partners); } } } } // Restricts the partners to only desirable types. For text and BRT_HLINE this // means the same type_ , and for image types it means any image type. void ColPartition::RefinePartnersByType(bool upper, ColPartition_CLIST* partners) { if (TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom())) { tprintf("Refining %s partners by type for:\n", upper ? "Upper" : "Lower"); Print(); } ColPartition_C_IT it(partners); // Purify text by type. if (blob_type_ > BRT_UNKNOWN || blob_type_ == BRT_HLINE) { // Keep only partners matching type_. // Exception: PT_VERTICAL_TEXT is allowed to stay with the other // text types if it is the only partner. for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); if (partner->type_ != type_ && (!partners->singleton() || (type_ != PT_VERTICAL_TEXT && partner->type_ != PT_VERTICAL_TEXT) || !IsTextType() || !partner->IsTextType())) { partner->RemovePartner(!upper, this); it.extract(); } else if (TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom())) { tprintf("Keeping partner:"); partner->Print(); } } } else { // Keep only images with images, but not being fussy about type. for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); if (partner->blob_type_ > BRT_UNKNOWN || partner->blob_type_ == BRT_HLINE) { partner->RemovePartner(!upper, this); it.extract(); } else if (TabFind::WithinTestRegion(2, bounding_box_.left(), bounding_box_.bottom())) { tprintf("Keeping partner:"); partner->Print(); } } } } // Remove transitive partnerships: this<->a, and a<->b and this<->b. // Gets rid of this<->b, leaving a clean chain. // Also if we have this<->a and a<->this, then gets rid of this<->a, as // this has multiple partners. void ColPartition::RefinePartnerShortcuts(bool upper, ColPartition_CLIST* partners) { bool done_any = false; do { done_any = false; ColPartition_C_IT it(partners); for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* a = it.data(); // Check for a match between all of a's partners (it1/b1) and all // of this's partners (it2/b2). ColPartition_C_IT it1(upper ? &a->upper_partners_ : &a->lower_partners_); for (it1.mark_cycle_pt(); !it1.cycled_list(); it1.forward()) { ColPartition* b1 = it1.data(); if (b1 == this) { done_any = true; it.extract(); a->RemovePartner(!upper, this); break; } ColPartition_C_IT it2(partners); for (it2.mark_cycle_pt(); !it2.cycled_list(); it2.forward()) { ColPartition* b2 = it2.data(); if (b1 == b2) { // Jackpot! b2 should not be a partner of this. it2.extract(); b2->RemovePartner(!upper, this); done_any = true; // That potentially invalidated all the iterators, so break out // and start again. break; } } if (done_any) break; } if (done_any) break; } } while (done_any && !partners->empty() && !partners->singleton()); } // Keeps the partner with the longest sequence of singleton matching partners. // Converts all others to pullout. void ColPartition::RefineFlowingTextPartners(bool upper, ColPartition_CLIST* partners) { ColPartition_C_IT it(partners); ColPartition* best_partner = it.data(); // Nasty iterative algorithm. int depth = 1; int survivors = 0; do { survivors = 0; for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); // See if it survives a chase to depth levels. for (int i = 0; i < depth && partner != NULL; ++i) { partner = partner->SingletonPartner(upper); if (partner != NULL && partner->type_ != PT_FLOWING_TEXT) partner = NULL; } if (partner != NULL) { ++survivors; best_partner = it.data(); } } ++depth; } while (survivors > 1 && depth <= kMaxPartnerDepth); // Keep only the best partner. for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); if (partner != best_partner) { partner->RemovePartner(!upper, this); it.extract(); // Change the types of partner to be PT_PULLOUT_TEXT. while (partner != NULL && partner->type_ == PT_FLOWING_TEXT) { partner->type_ = PT_PULLOUT_TEXT; partner = partner->SingletonPartner(upper); } } } } // Keep the partner with the biggest overlap. void ColPartition::RefinePartnersByOverlap(bool upper, ColPartition_CLIST* partners) { ColPartition_C_IT it(partners); ColPartition* best_partner = it.data(); // Find the partner with the best overlap. int best_overlap = 0; for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); int overlap = MIN(bounding_box_.right(), partner->bounding_box_.right()) - MAX(bounding_box_.left(), partner->bounding_box_.left()); if (overlap > best_overlap) { best_overlap = overlap; best_partner = partner; } } // Keep only the best partner. for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) { ColPartition* partner = it.data(); if (partner != best_partner) { partner->RemovePartner(!upper, this); it.extract(); } } } // Return true if bbox belongs better in this than other. bool ColPartition::ThisPartitionBetter(BLOBNBOX* bbox, const ColPartition& other) { TBOX box = bbox->bounding_box(); // Margins take priority. int left = box.left(); int right = box.right(); if (left < left_margin_ || right > right_margin_) return false; if (left < other.left_margin_ || right > other.right_margin_) return true; int top = box.top(); int bottom = box.bottom(); int this_overlap = MIN(top, median_top_) - MAX(bottom, median_bottom_); int other_overlap = MIN(top, other.median_top_) - MAX(bottom, other.median_bottom_); int this_miss = median_top_ - median_bottom_ - this_overlap; int other_miss = other.median_top_ - other.median_bottom_ - other_overlap; if (TabFind::WithinTestRegion(3, box.left(), box.bottom())) { tprintf("Unique on (%d,%d)->(%d,%d) overlap %d/%d, miss %d/%d, mt=%d/%d\n", box.left(), box.bottom(), box.right(), box.top(), this_overlap, other_overlap, this_miss, other_miss, median_top_, other.median_top_); } if (this_miss < other_miss) return true; if (this_miss > other_miss) return false; if (this_overlap > other_overlap) return true; if (this_overlap < other_overlap) return false; return median_top_ >= other.median_top_; } // Returns the median line-spacing between the current position and the end // of the list. // The iterator is passed by value so the iteration does not modify the // caller's iterator. static int MedianSpacing(int page_height, ColPartition_IT it) { STATS stats(0, page_height); while (!it.cycled_list()) { ColPartition* part = it.data(); it.forward(); stats.add(part->bottom_spacing(), 1); stats.add(part->top_spacing(), 1); } return static_cast(stats.median() + 0.5); } // Smoothes the spacings in the list into groups of equal linespacing. // resolution is the resolution of the original image, used as a basis // for thresholds in change of spacing. page_height is in pixels. void ColPartition::SmoothSpacings(int resolution, int page_height, ColPartition_LIST* parts) { // The task would be trivial if we didn't have to allow for blips - // occasional offsets in spacing caused by anomolous text, such as all // caps, groups of descenders, joined words, Arabic etc. // The neighbourhood stores a consecutive group of partitions so that // blips can be detected correctly, yet conservatively enough to not // mistake genuine spacing changes for blips. See example below. ColPartition* neighbourhood[PN_COUNT]; ColPartition_IT it(parts); it.mark_cycle_pt(); // Although we know nothing about the spacings is this list, the median is // used as an approximation to allow blips. // If parts of this block aren't spaced to the median, then we can't // accept blips in those parts, but we'll recalculate it each time we // split the block, so the median becomes more likely to match all the text. int median_space = MedianSpacing(page_height, it); ColPartition_IT start_it(it); ColPartition_IT end_it(it); for (int i = 0; i < PN_COUNT; ++i) { if (i < PN_UPPER || it.cycled_list()) { neighbourhood[i] = NULL; } else { if (i == PN_LOWER) end_it = it; neighbourhood[i] = it.data(); it.forward(); } } while (neighbourhood[PN_UPPER] != NULL) { // Test for end of a group. Normally SpacingsEqual is true within a group, // but in the case of a blip, it will be false. Here is an example: // Line enum Spacing below (spacing between tops of lines) // 1 ABOVE2 20 // 2 ABOVE1 20 // 3 UPPER 15 // 4 LOWER 25 // 5 BELOW1 20 // 6 BELOW2 20 // Line 4 is all in caps (regular caps), so the spacing between line 3 // and line 4 (looking at the tops) is smaller than normal, and the // spacing between line 4 and line 5 is larger than normal, but the // two of them add to twice the normal spacing. // The following if has to accept unequal spacings 3 times to pass the // blip (20/15, 15/25 and 25/20) // When the blip is in the middle, OKSpacingBlip tests that one of // ABOVE1 and BELOW1 matches the median. // The first time, everything is shifted down 1, so we present // OKSpacingBlip with neighbourhood+1 and check that PN_UPPER is median. // The last time, everything is shifted up 1, so we present OKSpacingBlip // with neighbourhood-1 and check that PN_LOWER matches the median. if (neighbourhood[PN_LOWER] == NULL || (!neighbourhood[PN_UPPER]->SpacingsEqual(*neighbourhood[PN_LOWER], resolution) && !OKSpacingBlip(resolution, median_space, neighbourhood) && (!OKSpacingBlip(resolution, median_space, neighbourhood - 1) || !neighbourhood[PN_LOWER]->SpacingEqual(median_space, resolution)) && (!OKSpacingBlip(resolution, median_space, neighbourhood + 1) || !neighbourhood[PN_UPPER]->SpacingEqual(median_space, resolution)))) { // The group has ended. PN_UPPER is the last member. // Compute the mean spacing over the group. ColPartition_IT sum_it(start_it); ColPartition* last_part = neighbourhood[PN_UPPER]; double total_bottom = 0.0; double total_top = 0.0; int total_count = 0; ColPartition* upper = sum_it.data(); // We do not process last_part, as its spacing is different. while (upper != last_part) { total_bottom += upper->bottom_spacing(); total_top += upper->top_spacing(); ++total_count; sum_it.forward(); upper = sum_it.data(); } if (total_count > 0) { // There were at least 2 lines, so set them all to the mean. int top_spacing = static_cast(total_top / total_count + 0.5); int bottom_spacing = static_cast(total_bottom / total_count + 0.5); if (textord_debug_tabfind) { tprintf("Spacing run ended. Cause:"); if (neighbourhood[PN_LOWER] == NULL) { tprintf("No more lines\n"); } else { tprintf("Spacing change. Spacings:\n"); for (int i = 0; i < PN_COUNT; ++i) { if (neighbourhood[i] == NULL) { tprintf("NULL\n"); } else { tprintf("Top = %d, bottom = %d\n", neighbourhood[i]->top_spacing(), neighbourhood[i]->bottom_spacing()); } } } tprintf("Mean spacing = %d/%d\n", top_spacing, bottom_spacing); } sum_it = start_it; upper = sum_it.data(); while (upper != last_part) { upper->set_top_spacing(top_spacing); upper->set_bottom_spacing(bottom_spacing); if (textord_debug_tabfind) { tprintf("Setting mean on:"); upper->Print(); } sum_it.forward(); upper = sum_it.data(); } } // PN_LOWER starts the next group and end_it is the next start_it. start_it = end_it; // Recalculate the median spacing to maximize the chances of detecting // spacing blips. median_space = MedianSpacing(page_height, end_it); } // Shuffle pointers. for (int j = 1; j < PN_COUNT; ++j) { neighbourhood[j - 1] = neighbourhood[j]; } if (it.cycled_list()) { neighbourhood[PN_COUNT - 1] = NULL; } else { neighbourhood[PN_COUNT - 1] = it.data(); it.forward(); } end_it.forward(); } } // Returns true if the parts array of pointers to partitions matches the // condition for a spacing blip. See SmoothSpacings for what this means // and how it is used. bool ColPartition::OKSpacingBlip(int resolution, int median_spacing, ColPartition** parts) { if (parts[PN_UPPER] == NULL || parts[PN_LOWER] == NULL) return false; // The blip is OK if upper and lower sum to an OK value and at least // one of above1 and below1 is equal to the median. return parts[PN_UPPER]->SummedSpacingOK(*parts[PN_LOWER], median_spacing, resolution) && ((parts[PN_ABOVE1] != NULL && parts[PN_ABOVE1]->SpacingEqual(median_spacing, resolution)) || (parts[PN_BELOW1] != NULL && parts[PN_BELOW1]->SpacingEqual(median_spacing, resolution))); } // Returns true if both the top and bottom spacings of this match the given // spacing to within suitable margins dictated by the image resolution. bool ColPartition::SpacingEqual(int spacing, int resolution) const { int bottom_error = BottomSpacingMargin(resolution); int top_error = TopSpacingMargin(resolution); return NearlyEqual(bottom_spacing_, spacing, bottom_error) && NearlyEqual(top_spacing_, spacing, top_error); } // Returns true if both the top and bottom spacings of this and other // match to within suitable margins dictated by the image resolution. bool ColPartition::SpacingsEqual(const ColPartition& other, int resolution) const { int bottom_error = MAX(BottomSpacingMargin(resolution), other.BottomSpacingMargin(resolution)); int top_error = MAX(TopSpacingMargin(resolution), other.TopSpacingMargin(resolution)); return NearlyEqual(bottom_spacing_, other.bottom_spacing_, bottom_error) && (NearlyEqual(top_spacing_, other.top_spacing_, top_error) || NearlyEqual(top_spacing_ + other.top_spacing_, bottom_spacing_ * 2, bottom_error)); } // Returns true if the sum spacing of this and other match the given // spacing (or twice the given spacing) to within a suitable margin dictated // by the image resolution. bool ColPartition::SummedSpacingOK(const ColPartition& other, int spacing, int resolution) const { int bottom_error = MAX(BottomSpacingMargin(resolution), other.BottomSpacingMargin(resolution)); int top_error = MAX(TopSpacingMargin(resolution), other.TopSpacingMargin(resolution)); int bottom_total = bottom_spacing_ + other.bottom_spacing_; int top_total = top_spacing_ + other.top_spacing_; return (NearlyEqual(spacing, bottom_total, bottom_error) && NearlyEqual(spacing, top_total, top_error)) || (NearlyEqual(spacing * 2, bottom_total, bottom_error) && NearlyEqual(spacing * 2, top_total, top_error)); } // Returns a suitable spacing margin that can be applied to bottoms of // text lines, based on the resolution and the stored side_step_. int ColPartition::BottomSpacingMargin(int resolution) const { return static_cast(kMaxSpacingDrift * resolution + 0.5) + side_step_; } // Returns a suitable spacing margin that can be applied to tops of // text lines, based on the resolution and the stored side_step_. int ColPartition::TopSpacingMargin(int resolution) const { return static_cast(kMaxTopSpacingFraction * median_size_ + 0.5) + BottomSpacingMargin(resolution); } // Returns true if the median text sizes of this and other agree to within // a reasonable multiplicative factor. bool ColPartition::SizesSimilar(const ColPartition& other) const { return median_size_ <= other.median_size_ * kMaxSizeRatio && other.median_size_ <= median_size_ * kMaxSizeRatio; } // Computes and returns in start, end a line segment formed from a // forwards-iterated group of left edges of partitions that satisfy the // condition that the rightmost left margin is to the left of the // leftmost left bounding box edge. // TODO(rays) Not good enough. Needs improving to tightly wrap text in both // directions, and to loosely wrap images. void ColPartition::LeftEdgeRun(ColPartition_IT* part_it, ICOORD* start, ICOORD* end) { ColPartition* part = part_it->data(); int start_y = part->bounding_box_.top(); if (!part_it->at_first() && part_it->data_relative(-1)->bounding_box_.bottom() > start_y) start_y = (start_y + part_it->data_relative(-1)->bounding_box_.bottom())/2; int end_y = part->bounding_box_.bottom(); int min_right = MAX_INT32; int max_left = MIN_INT32; do { part = part_it->data(); int top = part->bounding_box_.top(); int bottom = part->bounding_box_.bottom(); int tl_key = part->SortKey(part->left_margin_, top); int tr_key = part->SortKey(part->bounding_box_.left(), top); int bl_key = part->SortKey(part->left_margin_, bottom); int br_key = part->SortKey(part->bounding_box_.left(), bottom); int left_key = MAX(tl_key, bl_key); int right_key = MIN(tr_key, br_key); if (left_key <= min_right && right_key >= max_left) { // This part is good - let's keep it. min_right = MIN(min_right, right_key); max_left = MAX(max_left, left_key); end_y = bottom; part_it->forward(); if (!part_it->at_first() && part_it->data()->bounding_box_.top() < end_y) end_y = (end_y + part_it->data()->bounding_box_.top()) / 2; } else { if (textord_debug_tabfind) tprintf("Sum key %d/%d, new %d/%d\n", max_left, min_right, left_key, right_key); break; } } while (!part_it->at_first()); start->set_y(start_y); start->set_x(part->XAtY(min_right, start_y)); end->set_y(end_y); end->set_x(part->XAtY(min_right, end_y)); if (textord_debug_tabfind && !part_it->at_first()) tprintf("Left run from y=%d to %d terminated with sum %d-%d, new %d-%d\n", start_y, end_y, part->XAtY(max_left, end_y), end->x(), part->left_margin_, part->bounding_box_.left()); } // Computes and returns in start, end a line segment formed from a // backwards-iterated group of right edges of partitions that satisfy the // condition that the leftmost right margin is to the right of the // rightmost right bounding box edge. // TODO(rays) Not good enough. Needs improving to tightly wrap text in both // directions, and to loosely wrap images. void ColPartition::RightEdgeRun(ColPartition_IT* part_it, ICOORD* start, ICOORD* end) { ColPartition* part = part_it->data(); int start_y = part->bounding_box_.bottom(); if (!part_it->at_first() && part_it->data_relative(1)->bounding_box_.top() < start_y) start_y = (start_y + part_it->data_relative(1)->bounding_box_.top()) / 2; int end_y = part->bounding_box_.top(); int min_right = MAX_INT32; int max_left = MIN_INT32; do { part = part_it->data(); int top = part->bounding_box_.top(); int bottom = part->bounding_box_.bottom(); int tl_key = part->SortKey(part->bounding_box_.right(), top); int tr_key = part->SortKey(part->right_margin_, top); int bl_key = part->SortKey(part->bounding_box_.right(), bottom); int br_key = part->SortKey(part->right_margin_, bottom); int left_key = MAX(tl_key, bl_key); int right_key = MIN(tr_key, br_key); if (left_key <= min_right && right_key >= max_left) { // This part is good - let's keep it. min_right = MIN(min_right, right_key); max_left = MAX(max_left, left_key); end_y = top; part_it->backward(); if (!part_it->at_last() && part_it->data()->bounding_box_.bottom() > end_y) end_y = (end_y + part_it->data()->bounding_box_.bottom()) / 2; } else { if (textord_debug_tabfind) tprintf("Sum cross %d/%d, new %d/%d\n", max_left, min_right, left_key, right_key); break; } } while (!part_it->at_last()); start->set_y(start_y); start->set_x(part->XAtY(max_left, start_y)); end->set_y(end_y); end->set_x(part->XAtY(max_left, end_y)); if (textord_debug_tabfind && !part_it->at_last()) tprintf("Right run from y=%d to %d terminated with sum %d-%d, new %d-%d\n", start_y, end_y, end->x(), part->XAtY(min_right, end_y), part->bounding_box_.right(), part->right_margin_); } } // namespace tesseract.