lmh188
/
twain3.0
mirror of http://192.168.1.51:8099/lmh188/twain3.0
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
twain3.0/3rdparty/hgOCR/include/ccmain/pageiterator.cpp

632 lines
22 KiB
C++
Raw Blame History

///////////////////////////////////////////////////////////////////////
// File: pageiterator.cpp
// Description: Iterator for tesseract page structure that avoids using
// tesseract internal data structures.
// Author: Ray Smith
// Created: Fri Feb 26 14:32:09 PST 2010
//
// (C) Copyright 2010, 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 "pageiterator.h"
#include "allheaders.h"
#include "helpers.h"
#include "pageres.h"
#include "tesseractclass.h"
namespace 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_(page_res),
tesseract_(tesseract),
word_(NULL),
word_length_(0),
blob_index_(0),
cblob_it_(NULL),
include_upper_dots_(false),
include_lower_dots_(false),
scale_(scale),
scaled_yres_(scaled_yres),
rect_left_(rect_left),
rect_top_(rect_top),
rect_width_(rect_width),
rect_height_(rect_height) {
it_ = new PAGE_RES_IT(page_res);
PageIterator::Begin();
}
PageIterator::~PageIterator() {
delete it_;
delete cblob_it_;
}
/**
* 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.
*/
PageIterator::PageIterator(const PageIterator& src)
: page_res_(src.page_res_),
tesseract_(src.tesseract_),
word_(NULL),
word_length_(src.word_length_),
blob_index_(src.blob_index_),
cblob_it_(NULL),
include_upper_dots_(src.include_upper_dots_),
include_lower_dots_(src.include_lower_dots_),
scale_(src.scale_),
scaled_yres_(src.scaled_yres_),
rect_left_(src.rect_left_),
rect_top_(src.rect_top_),
rect_width_(src.rect_width_),
rect_height_(src.rect_height_) {
it_ = new PAGE_RES_IT(*src.it_);
BeginWord(src.blob_index_);
}
const PageIterator& PageIterator::operator=(const PageIterator& src) {
page_res_ = src.page_res_;
tesseract_ = src.tesseract_;
include_upper_dots_ = src.include_upper_dots_;
include_lower_dots_ = src.include_lower_dots_;
scale_ = src.scale_;
scaled_yres_ = src.scaled_yres_;
rect_left_ = src.rect_left_;
rect_top_ = src.rect_top_;
rect_width_ = src.rect_width_;
rect_height_ = src.rect_height_;
delete it_;
it_ = new PAGE_RES_IT(*src.it_);
BeginWord(src.blob_index_);
return *this;
}
bool PageIterator::PositionedAtSameWord(const PAGE_RES_IT* other) const {
return (it_ == NULL && it_ == other) ||
((other != NULL) && (it_ != NULL) && (*it_ == *other));
}
// ============= Moving around within the page ============.
/** Resets the iterator to point to the start of the page. */
void PageIterator::Begin() {
it_->restart_page_with_empties();
BeginWord(0);
}
void PageIterator::RestartParagraph() {
if (it_->block() == NULL) return; // At end of the document.
PAGE_RES_IT para(page_res_);
PAGE_RES_IT next_para(para);
next_para.forward_paragraph();
while (next_para.cmp(*it_) <= 0) {
para = next_para;
next_para.forward_paragraph();
}
*it_ = para;
BeginWord(0);
}
bool PageIterator::IsWithinFirstTextlineOfParagraph() const {
PageIterator p_start(*this);
p_start.RestartParagraph();
return p_start.it_->row() == it_->row();
}
void PageIterator::RestartRow() {
it_->restart_row();
BeginWord(0);
}
/**
* 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.
*/
bool PageIterator::Next(PageIteratorLevel level) {
if (it_->block() == NULL) return false; // Already at the end!
if (it_->word() == NULL)
level = RIL_BLOCK;
switch (level) {
case RIL_BLOCK:
it_->forward_block();
break;
case RIL_PARA:
it_->forward_paragraph();
break;
case RIL_TEXTLINE:
for (it_->forward_with_empties(); it_->row() == it_->prev_row();
it_->forward_with_empties());
break;
case RIL_WORD:
it_->forward_with_empties();
break;
case RIL_SYMBOL:
if (cblob_it_ != NULL)
cblob_it_->forward();
++blob_index_;
if (blob_index_ >= word_length_)
it_->forward_with_empties();
else
return true;
break;
}
BeginWord(0);
return it_->block() != NULL;
}
/**
* 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.
*/
bool PageIterator::IsAtBeginningOf(PageIteratorLevel level) const {
if (it_->block() == NULL) return false; // Already at the end!
if (it_->word() == NULL) return true; // In an image block.
switch (level) {
case RIL_BLOCK:
return blob_index_ == 0 && it_->block() != it_->prev_block();
case RIL_PARA:
return blob_index_ == 0 &&
(it_->block() != it_->prev_block() ||
it_->row()->row->para() != it_->prev_row()->row->para());
case RIL_TEXTLINE:
return blob_index_ == 0 && it_->row() != it_->prev_row();
case RIL_WORD:
return blob_index_ == 0;
case RIL_SYMBOL:
return true;
}
return 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)
*/
bool PageIterator::IsAtFinalElement(PageIteratorLevel level,
PageIteratorLevel element) const {
if (Empty(element)) return true; // Already at the end!
// The result is true if we step forward by element and find we are
// at the the end of the page or at beginning of *all* levels in:
// [level, element).
// When there is more than one level difference between element and level,
// we could for instance move forward one symbol and still be at the first
// word on a line, so we also have to be at the first symbol in a word.
PageIterator next(*this);
next.Next(element);
if (next.Empty(element)) return true; // Reached the end of the page.
while (element > level) {
element = static_cast<PageIteratorLevel>(element - 1);
if (!next.IsAtBeginningOf(element))
return false;
}
return true;
}
/**
* Returns whether this iterator is positioned
* before other: -1
* equal to other: 0
* after other: 1
*/
int PageIterator::Cmp(const PageIterator &other) const {
int word_cmp = it_->cmp(*other.it_);
if (word_cmp != 0)
return word_cmp;
if (blob_index_ < other.blob_index_)
return -1;
if (blob_index_ == other.blob_index_)
return 0;
return 1;
}
// ============= Accessing data ==============.
// Coordinate system:
// Integer coordinates are at the cracks between the pixels.
// The top-left corner of the top-left pixel in the image is at (0,0).
// The bottom-right corner of the bottom-right pixel in the image is at
// (width, height).
// Every bounding box goes from the top-left of the top-left contained
// pixel to the bottom-right of the bottom-right contained pixel, so
// the bounding box of the single top-left pixel in the image is:
// (0,0)->(1,1).
// If an image rectangle has been set in the API, then returned coordinates
// relate to the original (full) image, rather than the rectangle.
/**
* 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.
*/
bool PageIterator::BoundingBoxInternal(PageIteratorLevel level,
int* left, int* top,
int* right, int* bottom) const {
if (Empty(level))
return false;
TBOX box;
PARA *para = NULL;
switch (level) {
case RIL_BLOCK:
box = it_->block()->block->restricted_bounding_box(include_upper_dots_,
include_lower_dots_);
break;
case RIL_PARA:
para = it_->row()->row->para();
// explicit fall-through.
case RIL_TEXTLINE:
box = it_->row()->row->restricted_bounding_box(include_upper_dots_,
include_lower_dots_);
break;
case RIL_WORD:
box = it_->word()->word->restricted_bounding_box(include_upper_dots_,
include_lower_dots_);
break;
case RIL_SYMBOL:
if (cblob_it_ == NULL)
box = it_->word()->box_word->BlobBox(blob_index_);
else
box = cblob_it_->data()->bounding_box();
}
if (level == RIL_PARA) {
PageIterator other = *this;
other.Begin();
do {
if (other.it_->block() &&
other.it_->block()->block == it_->block()->block &&
other.it_->row() && other.it_->row()->row &&
other.it_->row()->row->para() == para) {
box = box.bounding_union(other.it_->row()->row->bounding_box());
}
} while (other.Next(RIL_TEXTLINE));
}
if (level != RIL_SYMBOL || cblob_it_ != NULL)
box.rotate(it_->block()->block->re_rotation());
// Now we have a box in tesseract coordinates relative to the image rectangle,
// we have to convert the coords to a top-down system.
const int pix_height = pixGetHeight(tesseract_->pix_binary());
const int pix_width = pixGetWidth(tesseract_->pix_binary());
*left = ClipToRange(static_cast<int>(box.left()), 0, pix_width);
*top = ClipToRange(pix_height - box.top(), 0, pix_height);
*right = ClipToRange(static_cast<int>(box.right()), *left, pix_width);
*bottom = ClipToRange(pix_height - box.bottom(), *top, pix_height);
return true;
}
/**
* 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.
*/
bool PageIterator::BoundingBox(PageIteratorLevel level,
int* left, int* top,
int* right, int* bottom) const {
return BoundingBox(level, 0, left, top, right, bottom);
}
bool PageIterator::BoundingBox(PageIteratorLevel level, const int padding,
int* left, int* top,
int* right, int* bottom) const {
if (!BoundingBoxInternal(level, left, top, right, bottom))
return false;
// Convert to the coordinate system of the original image.
*left = ClipToRange(*left / scale_ + rect_left_ - padding,
rect_left_, rect_left_ + rect_width_);
*top = ClipToRange(*top / scale_ + rect_top_ - padding,
rect_top_, rect_top_ + rect_height_);
*right = ClipToRange((*right + scale_ - 1) / scale_ + rect_left_ + padding,
*left, rect_left_ + rect_width_);
*bottom = ClipToRange((*bottom + scale_ - 1) / scale_ + rect_top_ + padding,
*top, rect_top_ + rect_height_);
return true;
}
/** Return that there is no such object at a given level. */
bool PageIterator::Empty(PageIteratorLevel level) const {
if (it_->block() == NULL) return true; // Already at the end!
if (it_->word() == NULL && level != RIL_BLOCK) return true; // image block
if (level == RIL_SYMBOL && blob_index_ >= word_length_)
return true; // Zero length word, or already at the end of it.
return false;
}
/** Returns the type of the current block. See apitypes.h for PolyBlockType. */
PolyBlockType PageIterator::BlockType() const {
if (it_->block() == NULL || it_->block()->block == NULL)
return PT_UNKNOWN; // Already at the end!
if (it_->block()->block->poly_block() == NULL)
return PT_FLOWING_TEXT; // No layout analysis used - assume text.
return it_->block()->block->poly_block()->isA();
}
/** Returns the polygon outline of the current block. The returned Pta must
* be ptaDestroy-ed after use. */
Pta* PageIterator::BlockPolygon() const {
if (it_->block() == NULL || it_->block()->block == NULL)
return NULL; // Already at the end!
if (it_->block()->block->poly_block() == NULL)
return NULL; // No layout analysis used - no polygon.
ICOORDELT_IT it(it_->block()->block->poly_block()->points());
Pta* pta = ptaCreate(it.length());
int num_pts = 0;
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward(), ++num_pts) {
ICOORD* pt = it.data();
// Convert to top-down coords within the input image.
float x = static_cast<float>(pt->x()) / scale_ + rect_left_;
float y = rect_top_ + rect_height_ - static_cast<float>(pt->y()) / scale_;
ptaAddPt(pta, x, y);
}
return pta;
}
/**
* 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.
*/
Pix* PageIterator::GetBinaryImage(PageIteratorLevel level) const {
int left, top, right, bottom;
if (!BoundingBoxInternal(level, &left, &top, &right, &bottom))
return NULL;
if (level == RIL_SYMBOL && cblob_it_ != NULL &&
cblob_it_->data()->area() != 0)
return cblob_it_->data()->render();
Box* box = boxCreate(left, top, right - left, bottom - top);
Pix* pix = pixClipRectangle(tesseract_->pix_binary(), box, NULL);
boxDestroy(&box);
if (level == RIL_BLOCK || level == RIL_PARA) {
// Clip to the block polygon as well.
TBOX mask_box;
Pix* mask = it_->block()->block->render_mask(&mask_box);
int mask_x = left - mask_box.left();
int mask_y = top - (tesseract_->ImageHeight() - mask_box.top());
// AND the mask and pix, putting the result in pix.
pixRasterop(pix, MAX(0, -mask_x), MAX(0, -mask_y), pixGetWidth(pix),
pixGetHeight(pix), PIX_SRC & PIX_DST, mask, MAX(0, mask_x),
MAX(0, mask_y));
pixDestroy(&mask);
}
return pix;
}
/**
* 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.
*/
Pix* PageIterator::GetImage(PageIteratorLevel level, int padding,
Pix* original_img,
int* left, int* top) const {
int right, bottom;
if (!BoundingBox(level, left, top, &right, &bottom))
return NULL;
if (original_img == NULL)
return GetBinaryImage(level);
// Expand the box.
*left = MAX(*left - padding, 0);
*top = MAX(*top - padding, 0);
right = MIN(right + padding, rect_width_);
bottom = MIN(bottom + padding, rect_height_);
Box* box = boxCreate(*left, *top, right - *left, bottom - *top);
Pix* grey_pix = pixClipRectangle(original_img, box, NULL);
boxDestroy(&box);
if (level == RIL_BLOCK || level == RIL_PARA) {
// Clip to the block polygon as well.
TBOX mask_box;
Pix* mask = it_->block()->block->render_mask(&mask_box);
// Copy the mask registered correctly into an image the size of grey_pix.
int mask_x = *left - mask_box.left();
int mask_y = *top - (pixGetHeight(original_img) - mask_box.top());
int width = pixGetWidth(grey_pix);
int height = pixGetHeight(grey_pix);
Pix* resized_mask = pixCreate(width, height, 1);
pixRasterop(resized_mask, MAX(0, -mask_x), MAX(0, -mask_y), width, height,
PIX_SRC, mask, MAX(0, mask_x), MAX(0, mask_y));
pixDestroy(&mask);
pixDilateBrick(resized_mask, resized_mask, 2 * padding + 1,
2 * padding + 1);
pixInvert(resized_mask, resized_mask);
pixSetMasked(grey_pix, resized_mask, MAX_UINT32);
pixDestroy(&resized_mask);
}
return grey_pix;
}
/**
* 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!
*/
bool PageIterator::Baseline(PageIteratorLevel level,
int* x1, int* y1, int* x2, int* y2) const {
if (it_->word() == NULL) return false; // Already at the end!
ROW* row = it_->row()->row;
WERD* word = it_->word()->word;
TBOX box = (level == RIL_WORD || level == RIL_SYMBOL)
? word->bounding_box()
: row->bounding_box();
int left = box.left();
ICOORD startpt(left, static_cast<inT16>(row->base_line(left) + 0.5));
int right = box.right();
ICOORD endpt(right, static_cast<inT16>(row->base_line(right) + 0.5));
// Rotate to image coordinates and convert to global image coords.
startpt.rotate(it_->block()->block->re_rotation());
endpt.rotate(it_->block()->block->re_rotation());
*x1 = startpt.x() / scale_ + rect_left_;
*y1 = (rect_height_ - startpt.y()) / scale_ + rect_top_;
*x2 = endpt.x() / scale_ + rect_left_;
*y2 = (rect_height_ - endpt.y()) / scale_ + rect_top_;
return true;
}
void PageIterator::Orientation(tesseract::Orientation *orientation,
tesseract::WritingDirection *writing_direction,
tesseract::TextlineOrder *textline_order,
float *deskew_angle) const {
BLOCK* block = it_->block()->block;
// Orientation
FCOORD up_in_image(0.0, 1.0);
up_in_image.unrotate(block->classify_rotation());
up_in_image.rotate(block->re_rotation());
if (up_in_image.x() == 0.0F) {
if (up_in_image.y() > 0.0F) {
*orientation = ORIENTATION_PAGE_UP;
}
else {
*orientation = ORIENTATION_PAGE_DOWN;
}
}
else if (up_in_image.x() > 0.0F) {
*orientation = ORIENTATION_PAGE_RIGHT;
}
else {
*orientation = ORIENTATION_PAGE_LEFT;
}
return;
// Writing direction
bool is_vertical_text = (block->classify_rotation().x() == 0.0);
bool right_to_left = block->right_to_left();
*writing_direction =
is_vertical_text
? WRITING_DIRECTION_TOP_TO_BOTTOM
: (right_to_left
? WRITING_DIRECTION_RIGHT_TO_LEFT
: WRITING_DIRECTION_LEFT_TO_RIGHT);
// Textline Order
bool is_mongolian = false; // TODO(eger): fix me
*textline_order = is_vertical_text
? (is_mongolian
? TEXTLINE_ORDER_LEFT_TO_RIGHT
: TEXTLINE_ORDER_RIGHT_TO_LEFT)
: TEXTLINE_ORDER_TOP_TO_BOTTOM;
// Deskew angle
FCOORD skew = block->skew(); // true horizontal for textlines
*deskew_angle = -skew.angle();
}
void PageIterator::ParagraphInfo(tesseract::ParagraphJustification *just,
bool *is_list_item,
bool *is_crown,
int *first_line_indent) const {
*just = tesseract::JUSTIFICATION_UNKNOWN;
if (!it_->row() || !it_->row()->row || !it_->row()->row->para() ||
!it_->row()->row->para()->model)
return;
PARA *para = it_->row()->row->para();
*is_list_item = para->is_list_item;
*is_crown = para->is_very_first_or_continuation;
*first_line_indent = para->model->first_indent() -
para->model->body_indent();
*just = para->model->justification();
}
/**
* Sets up the internal data for iterating the blobs of a new word, then
* moves the iterator to the given offset.
*/
void PageIterator::BeginWord(int offset) {
WERD_RES* word_res = it_->word();
if (word_res == NULL) {
// This is a non-text block, so there is no word.
word_length_ = 0;
blob_index_ = 0;
word_ = NULL;
return;
}
if (word_res->best_choice != NULL) {
// Recognition has been done, so we are using the box_word, which
// is already baseline denormalized.
word_length_ = word_res->best_choice->length();
if (word_res->box_word != NULL) {
if (word_res->box_word->length() != word_length_) {
tprintf("Corrupted word! best_choice[len=%d] = %s, box_word[len=%d]: ",
word_length_, word_res->best_choice->unichar_string().string(),
word_res->box_word->length());
word_res->box_word->bounding_box().print();
}
ASSERT_HOST(word_res->box_word->length() == word_length_);
}
word_ = NULL;
// We will be iterating the box_word.
delete cblob_it_;
cblob_it_ = NULL;
}
else {
// No recognition yet, so a "symbol" is a cblob.
word_ = word_res->word;
ASSERT_HOST(word_->cblob_list() != NULL);
word_length_ = word_->cblob_list()->length();
if (cblob_it_ == NULL) cblob_it_ = new C_BLOB_IT;
cblob_it_->set_to_list(word_->cblob_list());
}
for (blob_index_ = 0; blob_index_ < offset; ++blob_index_) {
if (cblob_it_ != NULL)
cblob_it_->forward();
}
}
bool PageIterator::SetWordBlamerBundle(BlamerBundle *blamer_bundle) {
if (it_->word() != NULL) {
it_->word()->blamer_bundle = blamer_bundle;
return true;
}
else {
return false;
}
}
} // namespace tesseract.
Reference in New Issue View Git Blame Copy Permalink