tesseract 4.1.1
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seam.cpp
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1/* -*-C-*-
2 ********************************************************************************
3 *
4 * File: seam.cpp (Formerly seam.c)
5 * Author: Mark Seaman, OCR Technology
6 *
7 * (c) Copyright 1987, Hewlett-Packard Company.
8 ** Licensed under the Apache License, Version 2.0 (the "License");
9 ** you may not use this file except in compliance with the License.
10 ** You may obtain a copy of the License at
11 ** http://www.apache.org/licenses/LICENSE-2.0
12 ** Unless required by applicable law or agreed to in writing, software
13 ** distributed under the License is distributed on an "AS IS" BASIS,
14 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 ** See the License for the specific language governing permissions and
16 ** limitations under the License.
17 *
18 *********************************************************************************/
19/*----------------------------------------------------------------------
20 I n c l u d e s
21----------------------------------------------------------------------*/
22#include "seam.h"
23#include "blobs.h"
24#include "tprintf.h"
25
26/*----------------------------------------------------------------------
27 Public Function Code
28----------------------------------------------------------------------*/
29
30// Returns the bounding box of all the points in the seam.
32 TBOX box(location_.x, location_.y, location_.x, location_.y);
33 for (int s = 0; s < num_splits_; ++s) {
34 box += splits_[s].bounding_box();
35 }
36 return box;
37}
38
39// Returns true if other can be combined into *this.
40bool SEAM::CombineableWith(const SEAM& other, int max_x_dist,
41 float max_total_priority) const {
42 int dist = location_.x - other.location_.x;
43 if (-max_x_dist < dist && dist < max_x_dist &&
44 num_splits_ + other.num_splits_ <= kMaxNumSplits &&
45 priority_ + other.priority_ < max_total_priority &&
46 !OverlappingSplits(other) && !SharesPosition(other)) {
47 return true;
48 } else {
49 return false;
50 }
51}
52
53// Combines other into *this. Only works if CombinableWith returned true.
54void SEAM::CombineWith(const SEAM& other) {
55 priority_ += other.priority_;
56 location_ += other.location_;
57 location_ /= 2;
58
59 for (uint8_t s = 0; s < other.num_splits_ && num_splits_ < kMaxNumSplits; ++s)
60 splits_[num_splits_++] = other.splits_[s];
61}
62
63// Returns true if the splits in *this SEAM appear OK in the sense that they
64// do not cross any outlines and do not chop off any ridiculously small
65// pieces.
66bool SEAM::IsHealthy(const TBLOB& blob, int min_points, int min_area) const {
67 // TODO(rays) Try testing all the splits. Duplicating original code for now,
68 // which tested only the first.
69 return num_splits_ == 0 || splits_[0].IsHealthy(blob, min_points, min_area);
70}
71
72// Computes the widthp_/widthn_ range for all existing SEAMs and for *this
73// seam, which is about to be inserted at insert_index. Returns false if
74// any of the computations fails, as this indicates an invalid chop.
75// widthn_/widthp_ are only changed if modify is true.
77 const GenericVector<TBLOB*>& blobs,
78 int insert_index, bool modify) {
79 for (int s = 0; s < insert_index; ++s) {
80 if (!seams[s]->FindBlobWidth(blobs, s, modify)) return false;
81 }
82 if (!FindBlobWidth(blobs, insert_index, modify)) return false;
83 for (int s = insert_index; s < seams.size(); ++s) {
84 if (!seams[s]->FindBlobWidth(blobs, s + 1, modify)) return false;
85 }
86 return true;
87}
88
89// Computes the widthp_/widthn_ range. Returns false if not all the splits
90// are accounted for. widthn_/widthp_ are only changed if modify is true.
91bool SEAM::FindBlobWidth(const GenericVector<TBLOB*>& blobs, int index,
92 bool modify) {
93 int num_found = 0;
94 if (modify) {
95 widthp_ = 0;
96 widthn_ = 0;
97 }
98 for (int s = 0; s < num_splits_; ++s) {
99 const SPLIT& split = splits_[s];
100 bool found_split = split.ContainedByBlob(*blobs[index]);
101 // Look right.
102 for (int b = index + 1; !found_split && b < blobs.size(); ++b) {
103 found_split = split.ContainedByBlob(*blobs[b]);
104 if (found_split && b - index > widthp_ && modify) widthp_ = b - index;
105 }
106 // Look left.
107 for (int b = index - 1; !found_split && b >= 0; --b) {
108 found_split = split.ContainedByBlob(*blobs[b]);
109 if (found_split && index - b > widthn_ && modify) widthn_ = index - b;
110 }
111 if (found_split) ++num_found;
112 }
113 return num_found == num_splits_;
114}
115
116// Splits this blob into two blobs by applying the splits included in
117// *this SEAM
118void SEAM::ApplySeam(bool italic_blob, TBLOB* blob, TBLOB* other_blob) const {
119 for (int s = 0; s < num_splits_; ++s) {
120 splits_[s].SplitOutlineList(blob->outlines);
121 }
122 blob->ComputeBoundingBoxes();
123
124 divide_blobs(blob, other_blob, italic_blob, location_);
125
127 other_blob->EliminateDuplicateOutlines();
128
129 blob->CorrectBlobOrder(other_blob);
130}
131
132// Undoes ApplySeam by removing the seam between these two blobs.
133// Produces one blob as a result, and deletes other_blob.
134void SEAM::UndoSeam(TBLOB* blob, TBLOB* other_blob) const {
135 if (blob->outlines == nullptr) {
136 blob->outlines = other_blob->outlines;
137 other_blob->outlines = nullptr;
138 }
139
140 TESSLINE* outline = blob->outlines;
141 while (outline->next) outline = outline->next;
142 outline->next = other_blob->outlines;
143 other_blob->outlines = nullptr;
144 delete other_blob;
145
146 for (int s = 0; s < num_splits_; ++s) {
147 splits_[s].UnsplitOutlineList(blob);
148 }
149 blob->ComputeBoundingBoxes();
151}
152
153// Prints everything in *this SEAM.
154void SEAM::Print(const char* label) const {
155 tprintf(label);
156 tprintf(" %6.2f @ (%d,%d), p=%d, n=%d ", priority_, location_.x, location_.y,
157 widthp_, widthn_);
158 for (int s = 0; s < num_splits_; ++s) {
159 splits_[s].Print();
160 if (s + 1 < num_splits_) tprintf(", ");
161 }
162 tprintf("\n");
163}
164
165// Prints a collection of SEAMs.
166/* static */
167void SEAM::PrintSeams(const char* label, const GenericVector<SEAM*>& seams) {
168 if (!seams.empty()) {
169 tprintf("%s\n", label);
170 for (int x = 0; x < seams.size(); ++x) {
171 tprintf("%2d: ", x);
172 seams[x]->Print("");
173 }
174 tprintf("\n");
175 }
176}
177
178#ifndef GRAPHICS_DISABLED
179// Draws the seam in the given window.
180void SEAM::Mark(ScrollView* window) const {
181 for (int s = 0; s < num_splits_; ++s) splits_[s].Mark(window);
182}
183#endif
184
185// Break up the blobs in this chain so that they are all independent.
186// This operation should undo the affect of join_pieces.
187/* static */
189 const GenericVector<TBLOB*>& blobs, int first,
190 int last) {
191 for (int x = first; x < last; ++x) seams[x]->Reveal();
192
193 TESSLINE* outline = blobs[first]->outlines;
194 int next_blob = first + 1;
195
196 while (outline != nullptr && next_blob <= last) {
197 if (outline->next == blobs[next_blob]->outlines) {
198 outline->next = nullptr;
199 outline = blobs[next_blob]->outlines;
200 ++next_blob;
201 } else {
202 outline = outline->next;
203 }
204 }
205}
206
207// Join a group of base level pieces into a single blob that can then
208// be classified.
209/* static */
211 const GenericVector<TBLOB*>& blobs, int first, int last) {
212 TESSLINE* outline = blobs[first]->outlines;
213 if (!outline)
214 return;
215
216 for (int x = first; x < last; ++x) {
217 SEAM *seam = seams[x];
218 if (x - seam->widthn_ >= first && x + seam->widthp_ < last) seam->Hide();
219 while (outline->next) outline = outline->next;
220 outline->next = blobs[x + 1]->outlines;
221 }
222}
223
224// Hides the seam so the outlines appear not to be cut by it.
225void SEAM::Hide() const {
226 for (int s = 0; s < num_splits_; ++s) {
227 splits_[s].Hide();
228 }
229}
230
231// Undoes hide, so the outlines are cut by the seam.
232void SEAM::Reveal() const {
233 for (int s = 0; s < num_splits_; ++s) {
234 splits_[s].Reveal();
235 }
236}
237
238// Computes and returns, but does not set, the full priority of *this SEAM.
239float SEAM::FullPriority(int xmin, int xmax, double overlap_knob,
240 int centered_maxwidth, double center_knob,
241 double width_change_knob) const {
242 if (num_splits_ == 0) return 0.0f;
243 for (int s = 1; s < num_splits_; ++s) {
244 splits_[s].SplitOutline();
245 }
246 float full_priority =
247 priority_ +
248 splits_[0].FullPriority(xmin, xmax, overlap_knob, centered_maxwidth,
249 center_knob, width_change_knob);
250 for (int s = num_splits_ - 1; s >= 1; --s) {
251 splits_[s].UnsplitOutlines();
252 }
253 return full_priority;
254}
255
264 seam_array->truncate(0);
265 TPOINT location;
266
267 for (int b = 1; b < word->NumBlobs(); ++b) {
268 TBOX bbox = word->blobs[b - 1]->bounding_box();
269 TBOX nbox = word->blobs[b]->bounding_box();
270 location.x = (bbox.right() + nbox.left()) / 2;
271 location.y = (bbox.bottom() + bbox.top() + nbox.bottom() + nbox.top()) / 4;
272 seam_array->push_back(new SEAM(0.0f, location));
273 }
274}
void divide_blobs(TBLOB *blob, TBLOB *other_blob, bool italic_blob, const TPOINT &location)
Definition: blobs.cpp:962
void start_seam_list(TWERD *word, GenericVector< SEAM * > *seam_array)
Definition: seam.cpp:263
DLLSYM void tprintf(const char *format,...)
Definition: tprintf.cpp:35
LIST last(LIST var_list)
Definition: oldlist.cpp:190
int push_back(T object)
bool empty() const
Definition: genericvector.h:91
int size() const
Definition: genericvector.h:72
void truncate(int size)
Definition: blobs.h:51
int16_t x
Definition: blobs.h:93
int16_t y
Definition: blobs.h:94
TESSLINE * next
Definition: blobs.h:281
Definition: blobs.h:284
void CorrectBlobOrder(TBLOB *next)
Definition: blobs.cpp:501
TESSLINE * outlines
Definition: blobs.h:400
void EliminateDuplicateOutlines()
Definition: blobs.cpp:480
void ComputeBoundingBoxes()
Definition: blobs.cpp:446
Definition: blobs.h:418
int NumBlobs() const
Definition: blobs.h:448
GenericVector< TBLOB * > blobs
Definition: blobs.h:459
Definition: rect.h:34
int16_t top() const
Definition: rect.h:58
int16_t left() const
Definition: rect.h:72
int16_t bottom() const
Definition: rect.h:65
int16_t right() const
Definition: rect.h:79
Definition: seam.h:38
float FullPriority(int xmin, int xmax, double overlap_knob, int centered_maxwidth, double center_knob, double width_change_knob) const
Definition: seam.cpp:239
TBOX bounding_box() const
Definition: seam.cpp:31
static void BreakPieces(const GenericVector< SEAM * > &seams, const GenericVector< TBLOB * > &blobs, int first, int last)
Definition: seam.cpp:188
bool SharesPosition(const SEAM &other) const
Definition: seam.h:89
void UndoSeam(TBLOB *blob, TBLOB *other_blob) const
Definition: seam.cpp:134
void Mark(ScrollView *window) const
Definition: seam.cpp:180
void Hide() const
Definition: seam.cpp:225
bool PrepareToInsertSeam(const GenericVector< SEAM * > &seams, const GenericVector< TBLOB * > &blobs, int insert_index, bool modify)
Definition: seam.cpp:76
bool FindBlobWidth(const GenericVector< TBLOB * > &blobs, int index, bool modify)
Definition: seam.cpp:91
bool IsHealthy(const TBLOB &blob, int min_points, int min_area) const
Definition: seam.cpp:66
void Reveal() const
Definition: seam.cpp:232
bool OverlappingSplits(const SEAM &other) const
Definition: seam.h:97
void ApplySeam(bool italic_blob, TBLOB *blob, TBLOB *other_blob) const
Definition: seam.cpp:118
static void JoinPieces(const GenericVector< SEAM * > &seams, const GenericVector< TBLOB * > &blobs, int first, int last)
Definition: seam.cpp:210
static void PrintSeams(const char *label, const GenericVector< SEAM * > &seams)
Definition: seam.cpp:167
bool CombineableWith(const SEAM &other, int max_x_dist, float max_total_priority) const
Definition: seam.cpp:40
void Print(const char *label) const
Definition: seam.cpp:154
void CombineWith(const SEAM &other)
Definition: seam.cpp:54
Definition: split.h:37
float FullPriority(int xmin, int xmax, double overlap_knob, int centered_maxwidth, double center_knob, double width_change_knob) const
Definition: split.cpp:81
bool ContainedByBlob(const TBLOB &blob) const
Definition: split.h:65
bool IsHealthy(const TBLOB &blob, int min_points, int min_area) const
Definition: split.cpp:115
void Reveal() const
Definition: split.cpp:65
void SplitOutlineList(TESSLINE *outlines) const
Definition: split.cpp:235
TBOX bounding_box() const
Definition: split.cpp:44
void Hide() const
Definition: split.cpp:51
void Print() const
Definition: split.cpp:219
void SplitOutline() const
Definition: split.cpp:254
void UnsplitOutlineList(TBLOB *blob) const
Definition: split.cpp:279
void UnsplitOutlines() const
Definition: split.cpp:295