tesseract 4.1.1
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tesseract::BoxChar Class Reference

#include <boxchar.h>

Public Member Functions

 BoxChar (const char *utf8_str, int len)
 
 ~BoxChar ()
 
const std::string & ch () const
 
const Box * box () const
 
const int & page () const
 
void set_rtl_index (int index)
 
const int & rtl_index () const
 
void AddBox (int x, int y, int width, int height)
 
void set_page (int page)
 
std::string * mutable_ch ()
 
Box * mutable_box ()
 
bool operator< (const BoxChar &other) const
 
void GetDirection (int *num_rtl, int *num_ltr) const
 
void ReverseUnicodesInBox ()
 

Static Public Member Functions

static void TranslateBoxes (int xshift, int yshift, std::vector< BoxChar * > *boxes)
 
static void PrepareToWrite (std::vector< BoxChar * > *boxes)
 
static void InsertNewlines (bool rtl_rules, bool vertical_rules, std::vector< BoxChar * > *boxes)
 
static void InsertSpaces (bool rtl_rules, bool vertical_rules, std::vector< BoxChar * > *boxes)
 
static void ReorderRTLText (std::vector< BoxChar * > *boxes)
 
static bool ContainsMostlyRTL (const std::vector< BoxChar * > &boxes)
 
static bool MostlyVertical (const std::vector< BoxChar * > &boxes)
 
static int TotalByteLength (const std::vector< BoxChar * > &boxes)
 
static void RotateBoxes (float rotation, int xcenter, int ycenter, int start_box, int end_box, std::vector< BoxChar * > *boxes)
 
static void WriteTesseractBoxFile (const std::string &name, int height, const std::vector< BoxChar * > &boxes)
 
static std::string GetTesseractBoxStr (int height, const std::vector< BoxChar * > &boxes)
 

Detailed Description

Definition at line 36 of file boxchar.h.

Constructor & Destructor Documentation

◆ BoxChar()

tesseract::BoxChar::BoxChar ( const char *  utf8_str,
int  len 
)

Definition at line 40 of file boxchar.cpp.

41 : ch_(utf8_str, len), box_(nullptr), page_(0), rtl_index_(-1) {}

◆ ~BoxChar()

tesseract::BoxChar::~BoxChar ( )

Definition at line 43 of file boxchar.cpp.

43{ boxDestroy(&box_); }

Member Function Documentation

◆ AddBox()

void tesseract::BoxChar::AddBox ( int  x,
int  y,
int  width,
int  height 
)

Definition at line 45 of file boxchar.cpp.

45 {
46 box_ = boxCreate(x, y, width, height);
47}

◆ box()

const Box * tesseract::BoxChar::box ( ) const
inline

Definition at line 44 of file boxchar.h.

44{ return box_; }

◆ ch()

const std::string & tesseract::BoxChar::ch ( ) const
inline

Definition at line 43 of file boxchar.h.

43{ return ch_; }

◆ ContainsMostlyRTL()

bool tesseract::BoxChar::ContainsMostlyRTL ( const std::vector< BoxChar * > &  boxes)
static

Definition at line 260 of file boxchar.cpp.

260 {
261 int num_rtl = 0, num_ltr = 0;
262 for (size_t i = 0; i < boxes.size(); ++i) {
263 boxes[i]->GetDirection(&num_rtl, &num_ltr);
264 }
265 return num_rtl > num_ltr;
266}

◆ GetDirection()

void tesseract::BoxChar::GetDirection ( int *  num_rtl,
int *  num_ltr 
) const

Definition at line 51 of file boxchar.cpp.

51 {
52 // Convert the unichar to UTF32 representation
53 std::vector<char32> uni_vector = UNICHAR::UTF8ToUTF32(ch_.c_str());
54 if (uni_vector.empty()) {
55 tprintf("Illegal utf8 in boxchar string:%s = ", ch_.c_str());
56 for (size_t c = 0; c < ch_.size(); ++c) {
57 tprintf(" 0x%x", ch_[c]);
58 }
59 tprintf("\n");
60 return;
61 }
62 for (char32 ch : uni_vector) {
63 UCharDirection dir = u_charDirection(ch);
64 if (dir == U_RIGHT_TO_LEFT || dir == U_RIGHT_TO_LEFT_ARABIC ||
65 dir == U_RIGHT_TO_LEFT_ISOLATE) {
66 ++*num_rtl;
67 } else if ((dir == U_ARABIC_NUMBER) ||
68 (dir != U_DIR_NON_SPACING_MARK && dir != U_BOUNDARY_NEUTRAL)) {
69 ++*num_ltr;
70 }
71 }
72}
DLLSYM void tprintf(const char *format,...)
Definition: tprintf.cpp:35
signed int char32
static std::vector< char32 > UTF8ToUTF32(const char *utf8_str)
Definition: unichar.cpp:215
const std::string & ch() const
Definition: boxchar.h:43

◆ GetTesseractBoxStr()

std::string tesseract::BoxChar::GetTesseractBoxStr ( int  height,
const std::vector< BoxChar * > &  boxes 
)
static

Definition at line 327 of file boxchar.cpp.

328 {
329 std::string output;
330 char buffer[kMaxLineLength];
331 for (size_t i = 0; i < boxes.size(); ++i) {
332 const Box* box = boxes[i]->box_;
333 if (box == nullptr) {
334 tprintf("Error: Call PrepareToWrite before WriteTesseractBoxFile!!\n");
335 return "";
336 }
337 int nbytes =
338 snprintf(buffer, kMaxLineLength, "%s %d %d %d %d %d\n",
339 boxes[i]->ch_.c_str(), box->x, height - box->y - box->h,
340 box->x + box->w, height - box->y, boxes[i]->page_);
341 output.append(buffer, nbytes);
342 }
343 return output;
344}
const int kMaxLineLength
Definition: boxchar.cpp:318
const Box * box() const
Definition: boxchar.h:44

◆ InsertNewlines()

void tesseract::BoxChar::InsertNewlines ( bool  rtl_rules,
bool  vertical_rules,
std::vector< BoxChar * > *  boxes 
)
static

Definition at line 112 of file boxchar.cpp.

113 {
114 size_t prev_i = SIZE_MAX;
115 int max_shift = 0;
116 for (size_t i = 0; i < boxes->size(); ++i) {
117 Box* box = (*boxes)[i]->box_;
118 if (box == nullptr) {
119 if (prev_i == SIZE_MAX || prev_i + 1 < i || i + 1 == boxes->size()) {
120 // Erase null boxes at the start of a line and after another null box.
121 do {
122 delete (*boxes)[i];
123 boxes->erase(boxes->begin() + i);
124 if (i == 0) break;
125 } while (i-- == boxes->size() && (*boxes)[i]->box_ == nullptr);
126 }
127 continue;
128 }
129 if (prev_i != SIZE_MAX) {
130 Box* prev_box = (*boxes)[prev_i]->box_;
131 int shift = box->x - prev_box->x;
132 if (vertical_rules) {
133 shift = box->y - prev_box->y;
134 } else if (rtl_rules) {
135 shift = -shift;
136 }
137 if (-shift > max_shift) {
138 // This is a newline. Since nothing cares about the size of the box,
139 // except the out-of-bounds checker, minimize the chance of creating
140 // a box outside the image by making the width and height 1.
141 int width = 1;
142 int height = 1;
143 int x = prev_box->x + prev_box->w;
144 int y = prev_box->y;
145 if (vertical_rules) {
146 x = prev_box->x;
147 y = prev_box->y + prev_box->h;
148 } else if (rtl_rules) {
149 x = prev_box->x - width;
150 if (x < 0) {
151 tprintf("prev x = %d, width=%d\n", prev_box->x, width);
152 x = 0;
153 }
154 }
155 if (prev_i + 1 == i) {
156 // New character needed.
157 BoxChar* new_box = new BoxChar("\t", 1);
158 new_box->AddBox(x, y, width, height);
159 new_box->page_ = (*boxes)[i]->page_;
160 boxes->insert(boxes->begin() + i, new_box);
161 ++i;
162 } else {
163 (*boxes)[i - 1]->AddBox(x, y, width, height);
164 (*boxes)[i - 1]->ch_ = "\t";
165 }
166 max_shift = 0;
167 } else if (shift > max_shift) {
168 max_shift = shift;
169 }
170 }
171 prev_i = i;
172 }
173}
BoxChar(const char *utf8_str, int len)
Definition: boxchar.cpp:40

◆ InsertSpaces()

void tesseract::BoxChar::InsertSpaces ( bool  rtl_rules,
bool  vertical_rules,
std::vector< BoxChar * > *  boxes 
)
static

Definition at line 177 of file boxchar.cpp.

178 {
179 // After InsertNewlines, any remaining null boxes are not newlines, and are
180 // singletons, so add a box to each remaining null box.
181 for (size_t i = 1; i + 1 < boxes->size(); ++i) {
182 Box* box = (*boxes)[i]->box_;
183 if (box == nullptr) {
184 Box* prev = (*boxes)[i - 1]->box_;
185 Box* next = (*boxes)[i + 1]->box_;
186 ASSERT_HOST(prev != nullptr && next != nullptr);
187 int top = std::min(prev->y, next->y);
188 int bottom = std::max(prev->y + prev->h, next->y + next->h);
189 int left = prev->x + prev->w;
190 int right = next->x;
191 if (vertical_rules) {
192 top = prev->y + prev->h;
193 bottom = next->y;
194 left = std::min(prev->x, next->x);
195 right = std::max(prev->x + prev->w, next->x + next->w);
196 } else if (rtl_rules) {
197 // With RTL we have to account for BiDi.
198 // Right becomes the min left of all prior boxes back to the first
199 // space or newline.
200 right = prev->x;
201 left = next->x + next->w;
202 for (int j = i - 2;
203 j >= 0 && (*boxes)[j]->ch_ != " " && (*boxes)[j]->ch_ != "\t";
204 --j) {
205 prev = (*boxes)[j]->box_;
206 ASSERT_HOST(prev != nullptr);
207 if (prev->x < right) {
208 right = prev->x;
209 }
210 }
211 // Left becomes the max right of all next boxes forward to the first
212 // space or newline.
213 for (size_t j = i + 2;
214 j < boxes->size() && (*boxes)[j]->box_ != nullptr &&
215 (*boxes)[j]->ch_ != "\t";
216 ++j) {
217 next = (*boxes)[j]->box_;
218 if (next->x + next->w > left) {
219 left = next->x + next->w;
220 }
221 }
222 }
223 // Italic and stylized characters can produce negative spaces, which
224 // Leptonica doesn't like, so clip to a positive size.
225 if (right <= left) right = left + 1;
226 if (bottom <= top) bottom = top + 1;
227 (*boxes)[i]->AddBox(left, top, right - left, bottom - top);
228 (*boxes)[i]->ch_ = " ";
229 }
230 }
231}
#define ASSERT_HOST(x)
Definition: errcode.h:88

◆ MostlyVertical()

bool tesseract::BoxChar::MostlyVertical ( const std::vector< BoxChar * > &  boxes)
static

Definition at line 270 of file boxchar.cpp.

270 {
271 int64_t total_dx = 0, total_dy = 0;
272 for (size_t i = 1; i < boxes.size(); ++i) {
273 if (boxes[i - 1]->box_ != nullptr && boxes[i]->box_ != nullptr &&
274 boxes[i - 1]->page_ == boxes[i]->page_) {
275 int dx = boxes[i]->box_->x - boxes[i - 1]->box_->x;
276 int dy = boxes[i]->box_->y - boxes[i - 1]->box_->y;
277 if (abs(dx) > abs(dy) * kMinNewlineRatio ||
278 abs(dy) > abs(dx) * kMinNewlineRatio) {
279 total_dx += dx * dx;
280 total_dy += dy * dy;
281 }
282 }
283 }
284 return total_dy > total_dx;
285}
const int kMinNewlineRatio
Definition: boxchar.cpp:36

◆ mutable_box()

Box * tesseract::BoxChar::mutable_box ( )
inline

Definition at line 55 of file boxchar.h.

55{ return box_; }

◆ mutable_ch()

std::string * tesseract::BoxChar::mutable_ch ( )
inline

Definition at line 54 of file boxchar.h.

54{ return &ch_; }

◆ operator<()

bool tesseract::BoxChar::operator< ( const BoxChar other) const
inline

Definition at line 59 of file boxchar.h.

59 {
60 if (box_ == nullptr) return true;
61 if (other.box_ == nullptr) return false;
62 return box_->x < other.box_->x;
63 }

◆ page()

const int & tesseract::BoxChar::page ( ) const
inline

Definition at line 45 of file boxchar.h.

45{ return page_; }

◆ PrepareToWrite()

void tesseract::BoxChar::PrepareToWrite ( std::vector< BoxChar * > *  boxes)
static

Definition at line 97 of file boxchar.cpp.

97 {
98 bool rtl_rules = ContainsMostlyRTL(*boxes);
99 bool vertical_rules = MostlyVertical(*boxes);
100 InsertNewlines(rtl_rules, vertical_rules, boxes);
101 InsertSpaces(rtl_rules, vertical_rules, boxes);
102 for (size_t i = 0; i < boxes->size(); ++i) {
103 if ((*boxes)[i]->box_ == nullptr) tprintf("Null box at index %zu\n", i);
104 }
105 if (rtl_rules) {
106 ReorderRTLText(boxes);
107 }
108}
static bool MostlyVertical(const std::vector< BoxChar * > &boxes)
Definition: boxchar.cpp:270
static void InsertSpaces(bool rtl_rules, bool vertical_rules, std::vector< BoxChar * > *boxes)
Definition: boxchar.cpp:177
static void ReorderRTLText(std::vector< BoxChar * > *boxes)
Definition: boxchar.cpp:235
static bool ContainsMostlyRTL(const std::vector< BoxChar * > &boxes)
Definition: boxchar.cpp:260
static void InsertNewlines(bool rtl_rules, bool vertical_rules, std::vector< BoxChar * > *boxes)
Definition: boxchar.cpp:112

◆ ReorderRTLText()

void tesseract::BoxChar::ReorderRTLText ( std::vector< BoxChar * > *  boxes)
static

Definition at line 235 of file boxchar.cpp.

235 {
236 // Ideally we need the inverse of the algorithm used by ResultIterator.
237 // For now, let's try a sort that reverses original positions for RTL
238 // characters, otherwise by x-position. This should be much closer to
239 // correct than just sorting by x-position.
240 size_t num_boxes = boxes->size();
241 for (size_t i = 0; i < num_boxes; ++i) {
242 int num_rtl = 0, num_ltr = 0;
243 (*boxes)[i]->GetDirection(&num_rtl, &num_ltr);
244 if (num_rtl > num_ltr) {
245 (*boxes)[i]->set_rtl_index(i);
246 (*boxes)[i]->ReverseUnicodesInBox();
247 }
248 }
249 BoxCharPtrSort sorter;
250 size_t end = 0;
251 for (size_t start = 0; start < boxes->size(); start = end + 1) {
252 end = start + 1;
253 while (end < boxes->size() && (*boxes)[end]->ch_ != "\t") ++end;
254 std::sort(boxes->begin() + start, boxes->begin() + end, sorter);
255 }
256}

◆ ReverseUnicodesInBox()

void tesseract::BoxChar::ReverseUnicodesInBox ( )

Definition at line 76 of file boxchar.cpp.

76 {
77 std::vector<char32> unicodes = UNICHAR::UTF8ToUTF32(ch_.c_str());
78 std::reverse(unicodes.begin(), unicodes.end());
79 ch_ = UNICHAR::UTF32ToUTF8(unicodes);
80}
static std::string UTF32ToUTF8(const std::vector< char32 > &str32)
Definition: unichar.cpp:232

◆ RotateBoxes()

void tesseract::BoxChar::RotateBoxes ( float  rotation,
int  xcenter,
int  ycenter,
int  start_box,
int  end_box,
std::vector< BoxChar * > *  boxes 
)
static

Definition at line 299 of file boxchar.cpp.

301 {
302 Boxa* orig = boxaCreate(0);
303 for (int i = start_box; i < end_box; ++i) {
304 BOX* box = (*boxes)[i]->box_;
305 if (box) boxaAddBox(orig, box, L_CLONE);
306 }
307 Boxa* rotated = boxaRotate(orig, xcenter, ycenter, rotation);
308 boxaDestroy(&orig);
309 for (int i = start_box, box_ind = 0; i < end_box; ++i) {
310 if ((*boxes)[i]->box_) {
311 boxDestroy(&((*boxes)[i]->box_));
312 (*boxes)[i]->box_ = boxaGetBox(rotated, box_ind++, L_CLONE);
313 }
314 }
315 boxaDestroy(&rotated);
316}

◆ rtl_index()

const int & tesseract::BoxChar::rtl_index ( ) const
inline

Definition at line 47 of file boxchar.h.

47{ return rtl_index_; }

◆ set_page()

void tesseract::BoxChar::set_page ( int  page)
inline

Definition at line 52 of file boxchar.h.

52{ page_ = page; }
const int & page() const
Definition: boxchar.h:45

◆ set_rtl_index()

void tesseract::BoxChar::set_rtl_index ( int  index)
inline

Definition at line 46 of file boxchar.h.

46{ rtl_index_ = index; }

◆ TotalByteLength()

int tesseract::BoxChar::TotalByteLength ( const std::vector< BoxChar * > &  boxes)
static

Definition at line 289 of file boxchar.cpp.

289 {
290 int total_length = 0;
291 for (size_t i = 0; i < boxes.size(); ++i)
292 total_length += boxes[i]->ch_.size();
293 return total_length;
294}

◆ TranslateBoxes()

void tesseract::BoxChar::TranslateBoxes ( int  xshift,
int  yshift,
std::vector< BoxChar * > *  boxes 
)
static

Definition at line 83 of file boxchar.cpp.

84 {
85 for (size_t i = 0; i < boxes->size(); ++i) {
86 BOX* box = (*boxes)[i]->box_;
87 if (box != nullptr) {
88 box->x += xshift;
89 box->y += yshift;
90 }
91 }
92}

◆ WriteTesseractBoxFile()

void tesseract::BoxChar::WriteTesseractBoxFile ( const std::string &  name,
int  height,
const std::vector< BoxChar * > &  boxes 
)
static

Definition at line 320 of file boxchar.cpp.

321 {
322 std::string output = GetTesseractBoxStr(height, boxes);
323 File::WriteStringToFileOrDie(output, filename);
324}
static std::string GetTesseractBoxStr(int height, const std::vector< BoxChar * > &boxes)
Definition: boxchar.cpp:327
static void WriteStringToFileOrDie(const std::string &str, const std::string &filename)
Definition: fileio.cpp:56

The documentation for this class was generated from the following files: