tesseract/training/boxchar.h

120 lines
4.2 KiB
C++

/**********************************************************************
* File: boxchar.h
* Description: Simple class to associate a Tesseract classification unit with
* its bounding box so that the boxes can be rotated as the image
* is rotated for degradation. Also includes routines to output
* the character-tagged boxes to a boxfile.
* Author: Ray Smith
* Created: Mon Nov 18 2013
*
* (C) Copyright 2013, 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_TRAINING_BOXCHAR_H_
#define TESSERACT_TRAINING_BOXCHAR_H_
#include <string>
#include <vector>
#include "allheaders.h" // from Leptonica
#ifdef USE_STD_NAMESPACE
using std::string;
using std::vector;
#endif
struct Box;
namespace tesseract {
class BoxChar {
public:
BoxChar(const char* utf8_str, int len);
~BoxChar();
// Accessors.
const string& ch() const { return ch_; }
const Box* box() const { return box_; }
const int& page() const { return page_; }
// Set the box_ member.
void AddBox(int x, int y, int width, int height);
void set_page(int page) { page_ = page; }
string* mutable_ch() { return &ch_; }
Box* mutable_box() { return box_; }
// Sort function for sorting by left edge of box. Note that this will not
// work properly until after InsertNewlines and InsertSpaces.
bool operator<(const BoxChar& other) const {
if (box_ == NULL) return true;
if (other.box_ == NULL) return false;
return box_->x < other.box_->x;
}
static void TranslateBoxes(int xshift, int yshift,
vector<BoxChar*>* boxes);
// Prepares for writing the boxes to a file by inserting newlines, spaces,
// and re-ordering so the boxes are strictly left-to-right.
static void PrepareToWrite(vector<BoxChar*>* boxes);
// Inserts newline (tab) characters into the vector at newline positions.
static void InsertNewlines(bool rtl_rules, bool vertical_rules,
vector<BoxChar*>* boxes);
// Converts NULL boxes to space characters, with appropriate bounding boxes.
static void InsertSpaces(bool rtl_rules, bool vertical_rules,
vector<BoxChar*>* boxes);
// Reorders text in a right-to-left script in left-to-right order.
static void ReorderRTLText(vector<BoxChar*>* boxes);
// Returns true if the vector contains mostly RTL characters.
static bool ContainsMostlyRTL(const vector<BoxChar*>& boxes);
// Returns true if the text is mostly laid out vertically.
static bool MostlyVertical(const vector<BoxChar*>& boxes);
// Returns the total length of all the strings in the boxes.
static int TotalByteLength(const vector<BoxChar*>& boxes);
// Rotate the vector of boxes between start and end by the given rotation.
// The rotation is in radians clockwise about the given center.
static void RotateBoxes(float rotation,
int xcenter,
int ycenter,
int start_box,
int end_box,
vector<BoxChar*>* boxes);
// Create a tesseract box file from the vector of boxes. The image height
// is needed to convert to tesseract coordinates.
static void WriteTesseractBoxFile(const string& name, int height,
const vector<BoxChar*>& boxes);
private:
string ch_;
Box* box_;
int page_;
};
// Sort predicate to sort a vector of BoxChar*.
struct BoxCharPtrSort {
bool operator()(const BoxChar* box1, const BoxChar* box2) const {
return *box1 < *box2;
}
};
} // namespace tesseract
#endif // TESSERACT_TRAINING_BOXCHAR_H_