tesseract-ocr/ccmain/pageiterator.h

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// File:        pageiterator.h
// Description: Iterator for tesseract page structure that avoids using
//              tesseract internal data structures.
// Author:      Ray Smith
// Created:     Fri Feb 26 11:01:06 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.
//

#ifndef TESSERACT_CCMAIN_PAGEITERATOR_H__
#define TESSERACT_CCMAIN_PAGEITERATOR_H__

#include "publictypes.h"
#include "platform.h"

class C_BLOB_IT;
class PBLOB_IT;
class PAGE_RES;
class PAGE_RES_IT;
class WERD;
struct Pix;

namespace tesseract {

class Tesseract;

class TESS_API PageIterator {
 public:
  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 PageIterator& operator=(const PageIterator& src);

  bool PositionedAtSameWord(const PAGE_RES_IT* other) const;

  // ============= Moving around within the page ============.

  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;

  // ============= 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.

  bool BoundingBox(PageIteratorLevel level,
                   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;

  Pix* GetBinaryImage(PageIteratorLevel level) const;

  Pix* GetImage(PageIteratorLevel level, int padding,
                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;

 protected:
  TESS_LOCAL void BeginWord(int offset);

  PAGE_RES* page_res_;
  Tesseract* tesseract_;
  PAGE_RES_IT* it_;
  WERD* word_;
  int word_length_;
  int blob_index_;
  C_BLOB_IT* cblob_it_;
  int scale_;
  int scaled_yres_;
  int rect_left_;
  int rect_top_;
  int rect_width_;
  int rect_height_;
};

}  // namespace tesseract.

#endif  // TESSERACT_CCMAIN_PAGEITERATOR_H__