tesseract 4.1.1
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tesseract::PageIterator Class Reference

#include <pageiterator.h>

Inheritance diagram for tesseract::PageIterator:
tesseract::LTRResultIterator tesseract::ResultIterator tesseract::MutableIterator

Public Member Functions

 PageIterator (PAGE_RES *page_res, Tesseract *tesseract, int scale, int scaled_yres, int rect_left, int rect_top, int rect_width, int rect_height)
 
virtual ~PageIterator ()
 
 PageIterator (const PageIterator &src)
 
const PageIteratoroperator= (const PageIterator &src)
 
bool PositionedAtSameWord (const PAGE_RES_IT *other) const
 
virtual void Begin ()
 
virtual void RestartParagraph ()
 
bool IsWithinFirstTextlineOfParagraph () const
 
virtual void RestartRow ()
 
virtual bool Next (PageIteratorLevel level)
 
virtual bool IsAtBeginningOf (PageIteratorLevel level) const
 
virtual bool IsAtFinalElement (PageIteratorLevel level, PageIteratorLevel element) const
 
int Cmp (const PageIterator &other) const
 
void SetBoundingBoxComponents (bool include_upper_dots, bool include_lower_dots)
 
bool BoundingBox (PageIteratorLevel level, int *left, int *top, int *right, int *bottom) const
 
bool BoundingBox (PageIteratorLevel level, int padding, int *left, int *top, int *right, int *bottom) const
 
bool BoundingBoxInternal (PageIteratorLevel level, int *left, int *top, int *right, int *bottom) const
 
bool Empty (PageIteratorLevel level) const
 
PolyBlockType BlockType () const
 
Pta * BlockPolygon () const
 
Pix * GetBinaryImage (PageIteratorLevel level) const
 
Pix * GetImage (PageIteratorLevel level, int padding, Pix *original_img, int *left, int *top) const
 
bool Baseline (PageIteratorLevel level, int *x1, int *y1, int *x2, int *y2) const
 
void Orientation (tesseract::Orientation *orientation, tesseract::WritingDirection *writing_direction, tesseract::TextlineOrder *textline_order, float *deskew_angle) const
 
void ParagraphInfo (tesseract::ParagraphJustification *justification, bool *is_list_item, bool *is_crown, int *first_line_indent) const
 
bool SetWordBlamerBundle (BlamerBundle *blamer_bundle)
 

Protected Member Functions

TESS_LOCAL void BeginWord (int offset)
 

Protected Attributes

PAGE_RESpage_res_
 
Tesseracttesseract_
 
PAGE_RES_ITit_
 
WERDword_
 
int word_length_
 
int blob_index_
 
C_BLOB_IT * cblob_it_
 
bool include_upper_dots_
 
bool include_lower_dots_
 
int scale_
 
int scaled_yres_
 
int rect_left_
 
int rect_top_
 
int rect_width_
 
int rect_height_
 

Detailed Description

Class to iterate over tesseract page structure, providing access to all levels of the page hierarchy, without including any tesseract headers or having to handle any tesseract structures. WARNING! This class points to data held within the TessBaseAPI class, and therefore can only be used while the TessBaseAPI class still exists and has not been subjected to a call of Init, SetImage, Recognize, Clear, End DetectOS, or anything else that changes the internal PAGE_RES. See apitypes.h for the definition of PageIteratorLevel. See also ResultIterator, derived from PageIterator, which adds in the ability to access OCR output with text-specific methods.

Definition at line 52 of file pageiterator.h.

Constructor & Destructor Documentation

◆ PageIterator() [1/2]

tesseract::PageIterator::PageIterator ( PAGE_RES page_res,
Tesseract tesseract,
int  scale,
int  scaled_yres,
int  rect_left,
int  rect_top,
int  rect_width,
int  rect_height 
)

page_res and tesseract come directly from the BaseAPI. The rectangle parameters are copied indirectly from the Thresholder, via the BaseAPI. They represent the coordinates of some rectangle in an original image (in top-left-origin coordinates) and therefore the top-left needs to be added to any output boxes in order to specify coordinates in the original image. See TessBaseAPI::SetRectangle. The scale and scaled_yres are in case the Thresholder scaled the image rectangle prior to thresholding. Any coordinates in tesseract's image must be divided by scale before adding (rect_left, rect_top). The scaled_yres indicates the effective resolution of the binary image that tesseract has been given by the Thresholder. After the constructor, Begin has already been called.

Definition at line 31 of file pageiterator.cpp.

34 : page_res_(page_res),
36 word_(nullptr),
37 word_length_(0),
38 blob_index_(0),
39 cblob_it_(nullptr),
42 scale_(scale),
43 scaled_yres_(scaled_yres),
44 rect_left_(rect_left),
45 rect_top_(rect_top),
46 rect_width_(rect_width),
47 rect_height_(rect_height) {
48 it_ = new PAGE_RES_IT(page_res);
50}

◆ ~PageIterator()

tesseract::PageIterator::~PageIterator ( )
virtual

Definition at line 52 of file pageiterator.cpp.

52 {
53 delete it_;
54 delete cblob_it_;
55}

◆ PageIterator() [2/2]

tesseract::PageIterator::PageIterator ( const PageIterator src)

Page/ResultIterators may be copied! This makes it possible to iterate over all the objects at a lower level, while maintaining an iterator to objects at a higher level. These constructors DO NOT CALL Begin, so iterations will continue from the location of src.

PageIterators may be copied! This makes it possible to iterate over all the objects at a lower level, while maintaining an iterator to objects at a higher level.

Definition at line 62 of file pageiterator.cpp.

63 : page_res_(src.page_res_),
64 tesseract_(src.tesseract_),
65 word_(nullptr),
66 word_length_(src.word_length_),
67 blob_index_(src.blob_index_),
68 cblob_it_(nullptr),
69 include_upper_dots_(src.include_upper_dots_),
70 include_lower_dots_(src.include_lower_dots_),
71 scale_(src.scale_),
72 scaled_yres_(src.scaled_yres_),
73 rect_left_(src.rect_left_),
74 rect_top_(src.rect_top_),
75 rect_width_(src.rect_width_),
76 rect_height_(src.rect_height_) {
77 it_ = new PAGE_RES_IT(*src.it_);
78 BeginWord(src.blob_index_);
79}
TESS_LOCAL void BeginWord(int offset)

Member Function Documentation

◆ Baseline()

bool tesseract::PageIterator::Baseline ( PageIteratorLevel  level,
int *  x1,
int *  y1,
int *  x2,
int *  y2 
) const

Returns the baseline of the current object at the given level. The baseline is the line that passes through (x1, y1) and (x2, y2). WARNING: with vertical text, baselines may be vertical! Returns false if there is no baseline at the current position.

Returns the baseline of the current object at the given level. The baseline is the line that passes through (x1, y1) and (x2, y2). WARNING: with vertical text, baselines may be vertical!

Definition at line 497 of file pageiterator.cpp.

498 {
499 if (it_->word() == nullptr) return false; // Already at the end!
500 ROW* row = it_->row()->row;
501 WERD* word = it_->word()->word;
502 TBOX box = (level == RIL_WORD || level == RIL_SYMBOL)
503 ? word->bounding_box()
504 : row->bounding_box();
505 int left = box.left();
506 ICOORD startpt(left, static_cast<int16_t>(row->base_line(left) + 0.5));
507 int right = box.right();
508 ICOORD endpt(right, static_cast<int16_t>(row->base_line(right) + 0.5));
509 // Rotate to image coordinates and convert to global image coords.
510 startpt.rotate(it_->block()->block->re_rotation());
511 endpt.rotate(it_->block()->block->re_rotation());
512 *x1 = startpt.x() / scale_ + rect_left_;
513 *y1 = (rect_height_ - startpt.y()) / scale_ + rect_top_;
514 *x2 = endpt.x() / scale_ + rect_left_;
515 *y2 = (rect_height_ - endpt.y()) / scale_ + rect_top_;
516 return true;
517}
FCOORD re_rotation() const
Definition: ocrblock.h:134
Definition: ocrrow.h:37
float base_line(float xpos) const
Definition: ocrrow.h:59
TBOX bounding_box() const
Definition: ocrrow.h:88
BLOCK * block
Definition: pageres.h:116
ROW * row
Definition: pageres.h:140
WERD * word
Definition: pageres.h:186
WERD_RES * word() const
Definition: pageres.h:754
ROW_RES * row() const
Definition: pageres.h:757
BLOCK_RES * block() const
Definition: pageres.h:760
integer coordinate
Definition: points.h:32
Definition: rect.h:34
int16_t left() const
Definition: rect.h:72
int16_t right() const
Definition: rect.h:79
Definition: werd.h:56
TBOX bounding_box() const
Definition: werd.cpp:148

◆ Begin()

void tesseract::PageIterator::Begin ( )
virtual

Moves the iterator to point to the start of the page to begin an iteration.

Resets the iterator to point to the start of the page.

Reimplemented in tesseract::ResultIterator.

Definition at line 106 of file pageiterator.cpp.

106 {
108 BeginWord(0);
109}
WERD_RES * restart_page_with_empties()
Definition: pageres.h:704

◆ BeginWord()

void tesseract::PageIterator::BeginWord ( int  offset)
protected

Sets up the internal data for iterating the blobs of a new word, then moves the iterator to the given offset.

Definition at line 586 of file pageiterator.cpp.

586 {
587 WERD_RES* word_res = it_->word();
588 if (word_res == nullptr) {
589 // This is a non-text block, so there is no word.
590 word_length_ = 0;
591 blob_index_ = 0;
592 word_ = nullptr;
593 return;
594 }
595 if (word_res->best_choice != nullptr) {
596 // Recognition has been done, so we are using the box_word, which
597 // is already baseline denormalized.
598 word_length_ = word_res->best_choice->length();
599 if (word_res->box_word != nullptr) {
600 if (word_res->box_word->length() != word_length_) {
601 tprintf("Corrupted word! best_choice[len=%d] = %s, box_word[len=%d]: ",
603 word_res->box_word->length());
604 word_res->box_word->bounding_box().print();
605 }
606 ASSERT_HOST(word_res->box_word->length() == word_length_);
607 }
608 word_ = nullptr;
609 // We will be iterating the box_word.
610 delete cblob_it_;
611 cblob_it_ = nullptr;
612 } else {
613 // No recognition yet, so a "symbol" is a cblob.
614 word_ = word_res->word;
615 ASSERT_HOST(word_->cblob_list() != nullptr);
616 word_length_ = word_->cblob_list()->length();
617 if (cblob_it_ == nullptr) cblob_it_ = new C_BLOB_IT;
618 cblob_it_->set_to_list(word_->cblob_list());
619 }
620 for (blob_index_ = 0; blob_index_ < offset; ++blob_index_) {
621 if (cblob_it_ != nullptr)
622 cblob_it_->forward();
623 }
624}
#define ASSERT_HOST(x)
Definition: errcode.h:88
DLLSYM void tprintf(const char *format,...)
Definition: tprintf.cpp:35
int length() const
Definition: boxword.h:83
const TBOX & bounding_box() const
Definition: boxword.h:80
tesseract::BoxWord * box_word
Definition: pageres.h:272
WERD_CHOICE * best_choice
Definition: pageres.h:241
const STRING & unichar_string() const
Definition: ratngs.h:531
int length() const
Definition: ratngs.h:293
void print() const
Definition: rect.h:278
C_BLOB_LIST * cblob_list()
Definition: werd.h:95
const char * string() const
Definition: strngs.cpp:194

◆ BlockPolygon()

Pta * tesseract::PageIterator::BlockPolygon ( ) const

Returns the polygon outline of the current block. The returned Pta must be ptaDestroy-ed after use. Note that the returned Pta lists the vertices of the polygon, and the last edge is the line segment between the last point and the first point. nullptr will be returned if the iterator is at the end of the document or layout analysis was not used.

Returns the polygon outline of the current block. The returned Pta must be ptaDestroy-ed after use.

Definition at line 369 of file pageiterator.cpp.

369 {
370 if (it_->block() == nullptr || it_->block()->block == nullptr)
371 return nullptr; // Already at the end!
372 if (it_->block()->block->pdblk.poly_block() == nullptr)
373 return nullptr; // No layout analysis used - no polygon.
374 // Copy polygon, so we can unrotate it to image coordinates.
375 POLY_BLOCK* internal_poly = it_->block()->block->pdblk.poly_block();
376 ICOORDELT_LIST vertices;
377 vertices.deep_copy(internal_poly->points(), ICOORDELT::deep_copy);
378 POLY_BLOCK poly(&vertices, internal_poly->isA());
379 poly.rotate(it_->block()->block->re_rotation());
380 ICOORDELT_IT it(poly.points());
381 Pta* pta = ptaCreate(it.length());
382 int num_pts = 0;
383 for (it.mark_cycle_pt(); !it.cycled_list(); it.forward(), ++num_pts) {
384 ICOORD* pt = it.data();
385 // Convert to top-down coords within the input image.
386 int x = static_cast<float>(pt->x()) / scale_ + rect_left_;
387 int y = rect_top_ + rect_height_ - static_cast<float>(pt->y()) / scale_;
390 ptaAddPt(pta, x, y);
391 }
392 return pta;
393}
T ClipToRange(const T &x, const T &lower_bound, const T &upper_bound)
Definition: helpers.h:108
PDBLK pdblk
Page Description Block.
Definition: ocrblock.h:190
POLY_BLOCK * poly_block() const
Definition: pdblock.h:55
int16_t y() const
access_function
Definition: points.h:56
int16_t x() const
access function
Definition: points.h:52
static ICOORDELT * deep_copy(const ICOORDELT *src)
Definition: points.h:179
ICOORDELT_LIST * points()
Definition: polyblk.h:39
PolyBlockType isA() const
Definition: polyblk.h:45

◆ BlockType()

PolyBlockType tesseract::PageIterator::BlockType ( ) const

Returns the type of the current block. See apitypes.h for PolyBlockType.

Definition at line 359 of file pageiterator.cpp.

359 {
360 if (it_->block() == nullptr || it_->block()->block == nullptr)
361 return PT_UNKNOWN; // Already at the end!
362 if (it_->block()->block->pdblk.poly_block() == nullptr)
363 return PT_FLOWING_TEXT; // No layout analysis used - assume text.
364 return it_->block()->block->pdblk.poly_block()->isA();
365}
@ PT_FLOWING_TEXT
Definition: capi.h:130
@ PT_UNKNOWN
Definition: capi.h:129

◆ BoundingBox() [1/2]

bool tesseract::PageIterator::BoundingBox ( PageIteratorLevel  level,
int *  left,
int *  top,
int *  right,
int *  bottom 
) const

Returns the bounding rectangle of the current object at the given level. See comment on coordinate system above. Returns false if there is no such object at the current position. The returned bounding box is guaranteed to match the size and position of the image returned by GetBinaryImage, but may clip foreground pixels from a grey image. The padding argument to GetImage can be used to expand the image to include more foreground pixels. See GetImage below.

Returns the bounding rectangle of the current object at the given level in coordinates of the original image. See comment on coordinate system above. Returns false if there is no such object at the current position.

Definition at line 326 of file pageiterator.cpp.

328 {
329 return BoundingBox(level, 0, left, top, right, bottom);
330}
bool BoundingBox(PageIteratorLevel level, int *left, int *top, int *right, int *bottom) const

◆ BoundingBox() [2/2]

bool tesseract::PageIterator::BoundingBox ( PageIteratorLevel  level,
int  padding,
int *  left,
int *  top,
int *  right,
int *  bottom 
) const

Definition at line 332 of file pageiterator.cpp.

334 {
335 if (!BoundingBoxInternal(level, left, top, right, bottom))
336 return false;
337 // Convert to the coordinate system of the original image.
338 *left = ClipToRange(*left / scale_ + rect_left_ - padding,
340 *top = ClipToRange(*top / scale_ + rect_top_ - padding,
342 *right = ClipToRange((*right + scale_ - 1) / scale_ + rect_left_ + padding,
343 *left, rect_left_ + rect_width_);
344 *bottom = ClipToRange((*bottom + scale_ - 1) / scale_ + rect_top_ + padding,
345 *top, rect_top_ + rect_height_);
346 return true;
347}
bool BoundingBoxInternal(PageIteratorLevel level, int *left, int *top, int *right, int *bottom) const

◆ BoundingBoxInternal()

bool tesseract::PageIterator::BoundingBoxInternal ( PageIteratorLevel  level,
int *  left,
int *  top,
int *  right,
int *  bottom 
) const

Returns the bounding rectangle of the object in a coordinate system of the working image rectangle having its origin at (rect_left_, rect_top_) with respect to the original image and is scaled by a factor scale_.

Returns the bounding rectangle of the current object at the given level in the coordinates of the working image that is pix_binary(). See comment on coordinate system above. Returns false if there is no such object at the current position.

Definition at line 266 of file pageiterator.cpp.

268 {
269 if (Empty(level))
270 return false;
271 TBOX box;
272 PARA *para = nullptr;
273 switch (level) {
274 case RIL_BLOCK:
277 break;
278 case RIL_PARA:
279 para = it_->row()->row->para();
280 // Fall through.
281 case RIL_TEXTLINE:
284 break;
285 case RIL_WORD:
288 break;
289 case RIL_SYMBOL:
290 if (cblob_it_ == nullptr)
291 box = it_->word()->box_word->BlobBox(blob_index_);
292 else
293 box = cblob_it_->data()->bounding_box();
294 }
295 if (level == RIL_PARA) {
296 PageIterator other = *this;
297 other.Begin();
298 do {
299 if (other.it_->block() &&
300 other.it_->block()->block == it_->block()->block &&
301 other.it_->row() && other.it_->row()->row &&
302 other.it_->row()->row->para() == para) {
303 box = box.bounding_union(other.it_->row()->row->bounding_box());
304 }
305 } while (other.Next(RIL_TEXTLINE));
306 }
307 if (level != RIL_SYMBOL || cblob_it_ != nullptr)
308 box.rotate(it_->block()->block->re_rotation());
309 // Now we have a box in tesseract coordinates relative to the image rectangle,
310 // we have to convert the coords to a top-down system.
311 const int pix_height = pixGetHeight(tesseract_->pix_binary());
312 const int pix_width = pixGetWidth(tesseract_->pix_binary());
313 *left = ClipToRange(static_cast<int>(box.left()), 0, pix_width);
314 *top = ClipToRange(pix_height - box.top(), 0, pix_height);
315 *right = ClipToRange(static_cast<int>(box.right()), *left, pix_width);
316 *bottom = ClipToRange(pix_height - box.bottom(), *top, pix_height);
317 return true;
318}
bool Empty(PageIteratorLevel level) const
PageIterator(PAGE_RES *page_res, Tesseract *tesseract, int scale, int scaled_yres, int rect_left, int rect_top, int rect_width, int rect_height)
Pix * pix_binary() const
const TBOX & BlobBox(int index) const
Definition: boxword.h:84
TBOX restricted_bounding_box(bool upper_dots, bool lower_dots) const
Definition: ocrblock.cpp:85
Definition: ocrpara.h:29
TBOX restricted_bounding_box(bool upper_dots, bool lower_dots) const
Definition: ocrrow.cpp:84
PARA * para() const
Definition: ocrrow.h:118
void rotate(const FCOORD &vec)
Definition: rect.h:197
int16_t top() const
Definition: rect.h:58
int16_t bottom() const
Definition: rect.h:65
TBOX bounding_union(const TBOX &box) const
Definition: rect.cpp:129
TBOX restricted_bounding_box(bool upper_dots, bool lower_dots) const
Definition: werd.cpp:152

◆ Cmp()

int tesseract::PageIterator::Cmp ( const PageIterator other) const

Returns whether this iterator is positioned before other: -1 equal to other: 0 after other: 1

Definition at line 236 of file pageiterator.cpp.

236 {
237 int word_cmp = it_->cmp(*other.it_);
238 if (word_cmp != 0)
239 return word_cmp;
240 if (blob_index_ < other.blob_index_)
241 return -1;
242 if (blob_index_ == other.blob_index_)
243 return 0;
244 return 1;
245}
int cmp(const PAGE_RES_IT &other) const
Definition: pageres.cpp:1145

◆ Empty()

bool tesseract::PageIterator::Empty ( PageIteratorLevel  level) const

Returns whether there is no object of a given level.

Return that there is no such object at a given level.

Definition at line 350 of file pageiterator.cpp.

350 {
351 if (it_->block() == nullptr) return true; // Already at the end!
352 if (it_->word() == nullptr && level != RIL_BLOCK) return true; // image block
353 if (level == RIL_SYMBOL && blob_index_ >= word_length_)
354 return true; // Zero length word, or already at the end of it.
355 return false;
356}

◆ GetBinaryImage()

Pix * tesseract::PageIterator::GetBinaryImage ( PageIteratorLevel  level) const

Returns a binary image of the current object at the given level. The position and size match the return from BoundingBoxInternal, and so this could be upscaled with respect to the original input image. Use pixDestroy to delete the image after use.

Returns a binary image of the current object at the given level. The position and size match the return from BoundingBoxInternal, and so this could be upscaled with respect to the original input image. Use pixDestroy to delete the image after use. The following methods are used to generate the images: RIL_BLOCK: mask the page image with the block polygon. RIL_TEXTLINE: Clip the rectangle of the line box from the page image. TODO(rays) fix this to generate and use a line polygon. RIL_WORD: Clip the rectangle of the word box from the page image. RIL_SYMBOL: Render the symbol outline to an image for cblobs (prior to recognition) or the bounding box otherwise. A reconstruction of the original image (using xor to check for double representation) should be reasonably accurate, apart from removed noise, at the block level. Below the block level, the reconstruction will be missing images and line separators. At the symbol level, kerned characters will be invade the bounding box if rendered after recognition, making an xor reconstruction inaccurate, but an or construction better. Before recognition, symbol-level reconstruction should be good, even with xor, since the images come from the connected components.

Definition at line 417 of file pageiterator.cpp.

417 {
418 int left, top, right, bottom;
419 if (!BoundingBoxInternal(level, &left, &top, &right, &bottom))
420 return nullptr;
421 if (level == RIL_SYMBOL && cblob_it_ != nullptr &&
422 cblob_it_->data()->area() != 0)
423 return cblob_it_->data()->render();
424 Box* box = boxCreate(left, top, right - left, bottom - top);
425 Pix* pix = pixClipRectangle(tesseract_->pix_binary(), box, nullptr);
426 boxDestroy(&box);
427 if (level == RIL_BLOCK || level == RIL_PARA) {
428 // Clip to the block polygon as well.
429 TBOX mask_box;
430 Pix* mask = it_->block()->block->render_mask(&mask_box);
431 int mask_x = left - mask_box.left();
432 int mask_y = top - (tesseract_->ImageHeight() - mask_box.top());
433 // AND the mask and pix, putting the result in pix.
434 pixRasterop(pix, std::max(0, -mask_x), std::max(0, -mask_y), pixGetWidth(pix),
435 pixGetHeight(pix), PIX_SRC & PIX_DST, mask, std::max(0, mask_x),
436 std::max(0, mask_y));
437 pixDestroy(&mask);
438 }
439 return pix;
440}
Pix * render_mask(TBOX *mask_box)
Definition: ocrblock.h:160

◆ GetImage()

Pix * tesseract::PageIterator::GetImage ( PageIteratorLevel  level,
int  padding,
Pix *  original_img,
int *  left,
int *  top 
) const

Returns an image of the current object at the given level in greyscale if available in the input. To guarantee a binary image use BinaryImage. NOTE that in order to give the best possible image, the bounds are expanded slightly over the binary connected component, by the supplied padding, so the top-left position of the returned image is returned in (left,top). These will most likely not match the coordinates returned by BoundingBox. If you do not supply an original image, you will get a binary one. Use pixDestroy to delete the image after use.

Definition at line 453 of file pageiterator.cpp.

455 {
456 int right, bottom;
457 if (!BoundingBox(level, left, top, &right, &bottom))
458 return nullptr;
459 if (original_img == nullptr)
460 return GetBinaryImage(level);
461
462 // Expand the box.
463 *left = std::max(*left - padding, 0);
464 *top = std::max(*top - padding, 0);
465 right = std::min(right + padding, rect_width_);
466 bottom = std::min(bottom + padding, rect_height_);
467 Box* box = boxCreate(*left, *top, right - *left, bottom - *top);
468 Pix* grey_pix = pixClipRectangle(original_img, box, nullptr);
469 boxDestroy(&box);
470 if (level == RIL_BLOCK || level == RIL_PARA) {
471 // Clip to the block polygon as well.
472 TBOX mask_box;
473 Pix* mask = it_->block()->block->render_mask(&mask_box);
474 // Copy the mask registered correctly into an image the size of grey_pix.
475 int mask_x = *left - mask_box.left();
476 int mask_y = *top - (pixGetHeight(original_img) - mask_box.top());
477 int width = pixGetWidth(grey_pix);
478 int height = pixGetHeight(grey_pix);
479 Pix* resized_mask = pixCreate(width, height, 1);
480 pixRasterop(resized_mask, std::max(0, -mask_x), std::max(0, -mask_y), width, height,
481 PIX_SRC, mask, std::max(0, mask_x), std::max(0, mask_y));
482 pixDestroy(&mask);
483 pixDilateBrick(resized_mask, resized_mask, 2 * padding + 1,
484 2 * padding + 1);
485 pixInvert(resized_mask, resized_mask);
486 pixSetMasked(grey_pix, resized_mask, UINT32_MAX);
487 pixDestroy(&resized_mask);
488 }
489 return grey_pix;
490}
Pix * GetBinaryImage(PageIteratorLevel level) const

◆ IsAtBeginningOf()

bool tesseract::PageIterator::IsAtBeginningOf ( PageIteratorLevel  level) const
virtual

Returns true if the iterator is at the start of an object at the given level.

For instance, suppose an iterator it is pointed to the first symbol of the first word of the third line of the second paragraph of the first block in a page, then: it.IsAtBeginningOf(RIL_BLOCK) = false it.IsAtBeginningOf(RIL_PARA) = false it.IsAtBeginningOf(RIL_TEXTLINE) = true it.IsAtBeginningOf(RIL_WORD) = true it.IsAtBeginningOf(RIL_SYMBOL) = true

Returns true if the iterator is at the start of an object at the given level. Possible uses include determining if a call to Next(RIL_WORD) moved to the start of a RIL_PARA.

Reimplemented in tesseract::ResultIterator.

Definition at line 186 of file pageiterator.cpp.

186 {
187 if (it_->block() == nullptr) return false; // Already at the end!
188 if (it_->word() == nullptr) return true; // In an image block.
189 switch (level) {
190 case RIL_BLOCK:
191 return blob_index_ == 0 && it_->block() != it_->prev_block();
192 case RIL_PARA:
193 return blob_index_ == 0 &&
194 (it_->block() != it_->prev_block() ||
195 it_->row()->row->para() != it_->prev_row()->row->para());
196 case RIL_TEXTLINE:
197 return blob_index_ == 0 && it_->row() != it_->prev_row();
198 case RIL_WORD:
199 return blob_index_ == 0;
200 case RIL_SYMBOL:
201 return true;
202 }
203 return false;
204}
BLOCK_RES * prev_block() const
Definition: pageres.h:751
ROW_RES * prev_row() const
Definition: pageres.h:748

◆ IsAtFinalElement()

bool tesseract::PageIterator::IsAtFinalElement ( PageIteratorLevel  level,
PageIteratorLevel  element 
) const
virtual

Returns whether the iterator is positioned at the last element in a given level. (e.g. the last word in a line, the last line in a block)

Here's some two-paragraph example

text. It starts off innocuously enough but quickly turns bizarre. The author inserts a cornucopia of words to guard against confused references.

Now take an iterator it pointed to the start of "bizarre." it.IsAtFinalElement(RIL_PARA, RIL_SYMBOL) = false it.IsAtFinalElement(RIL_PARA, RIL_WORD) = true it.IsAtFinalElement(RIL_BLOCK, RIL_WORD) = false

Returns whether the iterator is positioned at the last element in a given level. (e.g. the last word in a line, the last line in a block)

Reimplemented in tesseract::ResultIterator.

Definition at line 210 of file pageiterator.cpp.

211 {
212 if (Empty(element)) return true; // Already at the end!
213 // The result is true if we step forward by element and find we are
214 // at the the end of the page or at beginning of *all* levels in:
215 // [level, element).
216 // When there is more than one level difference between element and level,
217 // we could for instance move forward one symbol and still be at the first
218 // word on a line, so we also have to be at the first symbol in a word.
219 PageIterator next(*this);
220 next.Next(element);
221 if (next.Empty(element)) return true; // Reached the end of the page.
222 while (element > level) {
223 element = static_cast<PageIteratorLevel>(element - 1);
224 if (!next.IsAtBeginningOf(element))
225 return false;
226 }
227 return true;
228}

◆ IsWithinFirstTextlineOfParagraph()

bool tesseract::PageIterator::IsWithinFirstTextlineOfParagraph ( ) const

Return whether this iterator points anywhere in the first textline of a paragraph.

Definition at line 124 of file pageiterator.cpp.

124 {
125 PageIterator p_start(*this);
126 p_start.RestartParagraph();
127 return p_start.it_->row() == it_->row();
128}

◆ Next()

bool tesseract::PageIterator::Next ( PageIteratorLevel  level)
virtual

Moves to the start of the next object at the given level in the page hierarchy, and returns false if the end of the page was reached. NOTE that RIL_SYMBOL will skip non-text blocks, but all other PageIteratorLevel level values will visit each non-text block once. Think of non text blocks as containing a single para, with a single line, with a single imaginary word. Calls to Next with different levels may be freely intermixed. This function iterates words in right-to-left scripts correctly, if the appropriate language has been loaded into Tesseract.

Moves to the start of the next object at the given level in the page hierarchy, and returns false if the end of the page was reached. NOTE (CHANGED!) that ALL PageIteratorLevel level values will visit each non-text block at least once. Think of non text blocks as containing a single para, with at least one line, with a single imaginary word, containing a single symbol. The bounding boxes mark out any polygonal nature of the block, and PTIsTextType(BLockType()) is false for non-text blocks. Calls to Next with different levels may be freely intermixed. This function iterates words in right-to-left scripts correctly, if the appropriate language has been loaded into Tesseract.

Reimplemented in tesseract::ResultIterator.

Definition at line 148 of file pageiterator.cpp.

148 {
149 if (it_->block() == nullptr) return false; // Already at the end!
150 if (it_->word() == nullptr)
151 level = RIL_BLOCK;
152
153 switch (level) {
154 case RIL_BLOCK:
156 break;
157 case RIL_PARA:
159 break;
160 case RIL_TEXTLINE:
161 for (it_->forward_with_empties(); it_->row() == it_->prev_row();
163 break;
164 case RIL_WORD:
166 break;
167 case RIL_SYMBOL:
168 if (cblob_it_ != nullptr)
169 cblob_it_->forward();
170 ++blob_index_;
173 else
174 return true;
175 break;
176 }
177 BeginWord(0);
178 return it_->block() != nullptr;
179}
WERD_RES * forward_block()
Definition: pageres.cpp:1660
WERD_RES * forward_paragraph()
Definition: pageres.cpp:1645
WERD_RES * forward_with_empties()
Definition: pageres.h:738

◆ operator=()

const PageIterator & tesseract::PageIterator::operator= ( const PageIterator src)

Definition at line 81 of file pageiterator.cpp.

81 {
82 page_res_ = src.page_res_;
83 tesseract_ = src.tesseract_;
84 include_upper_dots_ = src.include_upper_dots_;
85 include_lower_dots_ = src.include_lower_dots_;
86 scale_ = src.scale_;
87 scaled_yres_ = src.scaled_yres_;
88 rect_left_ = src.rect_left_;
89 rect_top_ = src.rect_top_;
90 rect_width_ = src.rect_width_;
91 rect_height_ = src.rect_height_;
92 delete it_;
93 it_ = new PAGE_RES_IT(*src.it_);
94 BeginWord(src.blob_index_);
95 return *this;
96}

◆ Orientation()

void tesseract::PageIterator::Orientation ( tesseract::Orientation orientation,
tesseract::WritingDirection writing_direction,
tesseract::TextlineOrder textline_order,
float *  deskew_angle 
) const

Returns orientation for the block the iterator points to. orientation, writing_direction, textline_order: see publictypes.h deskew_angle: after rotating the block so the text orientation is upright, how many radians does one have to rotate the block anti-clockwise for it to be level? -Pi/4 <= deskew_angle <= Pi/4

Definition at line 519 of file pageiterator.cpp.

522 {
523 BLOCK* block = it_->block()->block;
524
525 // Orientation
526 FCOORD up_in_image(0.0, 1.0);
527 up_in_image.unrotate(block->classify_rotation());
528 up_in_image.rotate(block->re_rotation());
529
530 if (up_in_image.x() == 0.0F) {
531 if (up_in_image.y() > 0.0F) {
532 *orientation = ORIENTATION_PAGE_UP;
533 } else {
534 *orientation = ORIENTATION_PAGE_DOWN;
535 }
536 } else if (up_in_image.x() > 0.0F) {
537 *orientation = ORIENTATION_PAGE_RIGHT;
538 } else {
539 *orientation = ORIENTATION_PAGE_LEFT;
540 }
541
542 // Writing direction
543 bool is_vertical_text = (block->classify_rotation().x() == 0.0);
544 bool right_to_left = block->right_to_left();
545 *writing_direction =
546 is_vertical_text
548 : (right_to_left
551
552 // Textline Order
553 const bool is_mongolian = false; // TODO(eger): fix me
554 *textline_order = is_vertical_text
555 ? (is_mongolian
559
560 // Deskew angle
561 FCOORD skew = block->skew(); // true horizontal for textlines
562 *deskew_angle = -skew.angle();
563}
@ TEXTLINE_ORDER_LEFT_TO_RIGHT
Definition: publictypes.h:153
@ TEXTLINE_ORDER_RIGHT_TO_LEFT
Definition: publictypes.h:154
@ TEXTLINE_ORDER_TOP_TO_BOTTOM
Definition: publictypes.h:155
@ ORIENTATION_PAGE_LEFT
Definition: publictypes.h:124
@ ORIENTATION_PAGE_DOWN
Definition: publictypes.h:123
@ ORIENTATION_PAGE_UP
Definition: publictypes.h:121
@ ORIENTATION_PAGE_RIGHT
Definition: publictypes.h:122
@ WRITING_DIRECTION_TOP_TO_BOTTOM
Definition: publictypes.h:138
@ WRITING_DIRECTION_LEFT_TO_RIGHT
Definition: publictypes.h:136
@ WRITING_DIRECTION_RIGHT_TO_LEFT
Definition: publictypes.h:137
Definition: ocrblock.h:31
FCOORD skew() const
Definition: ocrblock.h:146
FCOORD classify_rotation() const
Definition: ocrblock.h:140
bool right_to_left() const
Definition: ocrblock.h:79
Definition: points.h:189
float angle() const
find angle
Definition: points.h:247
float x() const
Definition: points.h:207

◆ ParagraphInfo()

void tesseract::PageIterator::ParagraphInfo ( tesseract::ParagraphJustification justification,
bool *  is_list_item,
bool *  is_crown,
int *  first_line_indent 
) const

Returns information about the current paragraph, if available.

justification - LEFT if ragged right, or fully justified and script is left-to-right. RIGHT if ragged left, or fully justified and script is right-to-left. unknown if it looks like source code or we have very few lines. is_list_item - true if we believe this is a member of an ordered or unordered list. is_crown - true if the first line of the paragraph is aligned with the other lines of the paragraph even though subsequent paragraphs have first line indents. This typically indicates that this is the continuation of a previous paragraph or that it is the very first paragraph in the chapter. first_line_indent - For LEFT aligned paragraphs, the first text line of paragraphs of this kind are indented this many pixels from the left edge of the rest of the paragraph. for RIGHT aligned paragraphs, the first text line of paragraphs of this kind are indented this many pixels from the right edge of the rest of the paragraph. NOTE 1: This value may be negative. NOTE 2: if *is_crown == true, the first line of this paragraph is actually flush, and first_line_indent is set to the "common" first_line_indent for subsequent paragraphs in this block of text.

Definition at line 565 of file pageiterator.cpp.

568 {
570 if (!it_->row() || !it_->row()->row || !it_->row()->row->para() ||
571 !it_->row()->row->para()->model)
572 return;
573
574 PARA *para = it_->row()->row->para();
575 *is_list_item = para->is_list_item;
576 *is_crown = para->is_very_first_or_continuation;
577 *first_line_indent = para->model->first_indent() -
578 para->model->body_indent();
579 *just = para->model->justification();
580}
@ JUSTIFICATION_UNKNOWN
Definition: publictypes.h:252
const ParagraphModel * model
Definition: ocrpara.h:36
bool is_very_first_or_continuation
Definition: ocrpara.h:43
bool is_list_item
Definition: ocrpara.h:38
int first_indent() const
Definition: ocrpara.h:168
tesseract::ParagraphJustification justification() const
Definition: ocrpara.h:164
int body_indent() const
Definition: ocrpara.h:169

◆ PositionedAtSameWord()

bool tesseract::PageIterator::PositionedAtSameWord ( const PAGE_RES_IT other) const

Are we positioned at the same location as other?

Definition at line 98 of file pageiterator.cpp.

98 {
99 return (it_ == nullptr && it_ == other) ||
100 ((other != nullptr) && (it_ != nullptr) && (*it_ == *other));
101}

◆ RestartParagraph()

void tesseract::PageIterator::RestartParagraph ( )
virtual

Moves the iterator to the beginning of the paragraph. This class implements this functionality by moving it to the zero indexed blob of the first (leftmost) word on the first row of the paragraph.

Definition at line 111 of file pageiterator.cpp.

111 {
112 if (it_->block() == nullptr) return; // At end of the document.
114 PAGE_RES_IT next_para(para);
115 next_para.forward_paragraph();
116 while (next_para.cmp(*it_) <= 0) {
117 para = next_para;
118 next_para.forward_paragraph();
119 }
120 *it_ = para;
121 BeginWord(0);
122}

◆ RestartRow()

void tesseract::PageIterator::RestartRow ( )
virtual

Moves the iterator to the beginning of the text line. This class implements this functionality by moving it to the zero indexed blob of the first (leftmost) word of the row.

Definition at line 130 of file pageiterator.cpp.

130 {
131 it_->restart_row();
132 BeginWord(0);
133}
WERD_RES * restart_row()
Definition: pageres.cpp:1630

◆ SetBoundingBoxComponents()

void tesseract::PageIterator::SetBoundingBoxComponents ( bool  include_upper_dots,
bool  include_lower_dots 
)
inline

Controls what to include in a bounding box. Bounding boxes of all levels between RIL_WORD and RIL_BLOCK can include or exclude potential diacritics. Between layout analysis and recognition, it isn't known where all diacritics belong, so this control is used to include or exclude some diacritics that are above or below the main body of the word. In most cases where the placement is obvious, and after recognition, it doesn't make as much difference, as the diacritics will already be included in the word.

Definition at line 191 of file pageiterator.h.

192 {
193 include_upper_dots_ = include_upper_dots;
194 include_lower_dots_ = include_lower_dots;
195 }

◆ SetWordBlamerBundle()

bool tesseract::PageIterator::SetWordBlamerBundle ( BlamerBundle blamer_bundle)

Definition at line 626 of file pageiterator.cpp.

626 {
627 if (it_->word() != nullptr) {
628 it_->word()->blamer_bundle = blamer_bundle;
629 return true;
630 } else {
631 return false;
632 }
633}
BlamerBundle * blamer_bundle
Definition: pageres.h:252

Member Data Documentation

◆ blob_index_

int tesseract::PageIterator::blob_index_
protected

The current blob index within the word.

Definition at line 343 of file pageiterator.h.

◆ cblob_it_

C_BLOB_IT* tesseract::PageIterator::cblob_it_
protected

Iterator to the blobs within the word. If nullptr, then we are iterating OCR results in the box_word. Owned by this ResultIterator.

Definition at line 349 of file pageiterator.h.

◆ include_lower_dots_

bool tesseract::PageIterator::include_lower_dots_
protected

Definition at line 352 of file pageiterator.h.

◆ include_upper_dots_

bool tesseract::PageIterator::include_upper_dots_
protected

Control over what to include in bounding boxes.

Definition at line 351 of file pageiterator.h.

◆ it_

PAGE_RES_IT* tesseract::PageIterator::it_
protected

The iterator to the page_res_. Owned by this ResultIterator. A pointer just to avoid dragging in Tesseract includes.

Definition at line 334 of file pageiterator.h.

◆ page_res_

PAGE_RES* tesseract::PageIterator::page_res_
protected

Pointer to the page_res owned by the API.

Definition at line 327 of file pageiterator.h.

◆ rect_height_

int tesseract::PageIterator::rect_height_
protected

Definition at line 359 of file pageiterator.h.

◆ rect_left_

int tesseract::PageIterator::rect_left_
protected

Definition at line 356 of file pageiterator.h.

◆ rect_top_

int tesseract::PageIterator::rect_top_
protected

Definition at line 357 of file pageiterator.h.

◆ rect_width_

int tesseract::PageIterator::rect_width_
protected

Definition at line 358 of file pageiterator.h.

◆ scale_

int tesseract::PageIterator::scale_
protected

Parameters saved from the Thresholder. Needed to rebuild coordinates.

Definition at line 354 of file pageiterator.h.

◆ scaled_yres_

int tesseract::PageIterator::scaled_yres_
protected

Definition at line 355 of file pageiterator.h.

◆ tesseract_

Tesseract* tesseract::PageIterator::tesseract_
protected

Pointer to the Tesseract object owned by the API.

Definition at line 329 of file pageiterator.h.

◆ word_

WERD* tesseract::PageIterator::word_
protected

The current input WERD being iterated. If there is an output from OCR, then word_ is nullptr. Owned by the API

Definition at line 339 of file pageiterator.h.

◆ word_length_

int tesseract::PageIterator::word_length_
protected

The length of the current word_.

Definition at line 341 of file pageiterator.h.


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