tesseract  5.0.0
lstmboxrenderer.cpp
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1 /**********************************************************************
2  * File: lstmboxrenderer.cpp
3  * Description: Renderer for creating box file for LSTM training.
4  * based on the tsv renderer.
5  *
6  * (C) Copyright 2019, Google Inc.
7  ** Licensed under the Apache License, Version 2.0 (the "License");
8  ** you may not use this file except in compliance with the License.
9  ** You may obtain a copy of the License at
10  ** http://www.apache.org/licenses/LICENSE-2.0
11  ** Unless required by applicable law or agreed to in writing, software
12  ** distributed under the License is distributed on an "AS IS" BASIS,
13  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  ** See the License for the specific language governing permissions and
15  ** limitations under the License.
16  *
17  **********************************************************************/
18 
19 #include <tesseract/baseapi.h> // for TessBaseAPI
20 #include <tesseract/renderer.h>
21 #include "tesseractclass.h" // for Tesseract
22 
23 namespace tesseract {
24 
30 static void AddBoxToLSTM(int right, int bottom, int top, int image_height, int page_num,
31  std::string &text) {
32  text += " " + std::to_string(image_height - bottom);
33  text += " " + std::to_string(right + 5);
34  text += " " + std::to_string(image_height - top);
35  text += " " + std::to_string(page_num);
36 }
37 
38 char *TessBaseAPI::GetLSTMBoxText(int page_number = 0) {
39  if (tesseract_ == nullptr || (page_res_ == nullptr && Recognize(nullptr) < 0)) {
40  return nullptr;
41  }
42 
43  std::string lstm_box_str;
44  bool first_word = true;
45  int left = 0, top = 0, right = 0, bottom = 0;
46 
48  while (!res_it->Empty(RIL_BLOCK)) {
49  if (res_it->Empty(RIL_SYMBOL)) {
50  res_it->Next(RIL_SYMBOL);
51  continue;
52  }
53  if (!first_word) {
54  if (!(res_it->IsAtBeginningOf(RIL_TEXTLINE))) {
55  if (res_it->IsAtBeginningOf(RIL_WORD)) {
56  lstm_box_str += " " + std::to_string(left);
57  AddBoxToLSTM(right, bottom, top, image_height_, page_number, lstm_box_str);
58  lstm_box_str += "\n"; // end of row for word
59  } // word
60  } else {
61  if (res_it->IsAtBeginningOf(RIL_TEXTLINE)) {
62  lstm_box_str += "\t " + std::to_string(left);
63  AddBoxToLSTM(right, bottom, top, image_height_, page_number, lstm_box_str);
64  lstm_box_str += "\n"; // end of row for line
65  } // line
66  }
67  } // not first word
68  first_word = false;
69  // Use bounding box for whole line for everything
70  res_it->BoundingBox(RIL_TEXTLINE, &left, &top, &right, &bottom);
71  do {
72  lstm_box_str += std::unique_ptr<const char[]>(res_it->GetUTF8Text(RIL_SYMBOL)).get();
73  res_it->Next(RIL_SYMBOL);
74  } while (!res_it->Empty(RIL_BLOCK) && !res_it->IsAtBeginningOf(RIL_SYMBOL));
75  lstm_box_str += " " + std::to_string(left);
76  AddBoxToLSTM(right, bottom, top, image_height_, page_number, lstm_box_str);
77  lstm_box_str += "\n"; // end of row for symbol
78  }
79  if (!first_word) { // if first_word is true => empty page
80  lstm_box_str += "\t " + std::to_string(left);
81  AddBoxToLSTM(right, bottom, top, image_height_, page_number, lstm_box_str);
82  lstm_box_str += "\n"; // end of PAGE
83  }
84  char *ret = new char[lstm_box_str.length() + 1];
85  strcpy(ret, lstm_box_str.c_str());
86  delete res_it;
87  return ret;
88 }
89 
90 /**********************************************************************
91  * LSTMBox Renderer interface implementation
92  **********************************************************************/
94  : TessResultRenderer(outputbase, "box") {}
95 
97  const std::unique_ptr<const char[]> lstmbox(api->GetLSTMBoxText(imagenum()));
98  if (lstmbox == nullptr) {
99  return false;
100  }
101 
102  AppendString(lstmbox.get());
103 
104  return true;
105 }
106 
107 } // namespace tesseract.
int Recognize(ETEXT_DESC *monitor)
Definition: baseapi.cpp:831
PAGE_RES * page_res_
The page-level data.
Definition: baseapi.h:774
Tesseract * tesseract_
The underlying data object.
Definition: baseapi.h:767
char * GetLSTMBoxText(int page_number)
LTRResultIterator * GetLTRIterator()
Definition: baseapi.cpp:1296
char * GetUTF8Text(PageIteratorLevel level) const
virtual bool Next(PageIteratorLevel level)
virtual bool IsAtBeginningOf(PageIteratorLevel level) const
bool Empty(PageIteratorLevel level) const
bool BoundingBox(PageIteratorLevel level, int *left, int *top, int *right, int *bottom) const
void AppendString(const char *s)
Definition: renderer.cpp:111
bool AddImageHandler(TessBaseAPI *api) override
TessLSTMBoxRenderer(const char *outputbase)