1 files changed, 107 insertions, 0 deletions
diff --git a/tesseract/src/api/lstmboxrenderer.cpp b/tesseract/src/api/lstmboxrenderer.cpp
new file mode 100644
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+++ b/tesseract/src/api/lstmboxrenderer.cpp
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+/**********************************************************************
+ * File:        lstmboxrenderer.cpp
+ * Description: Renderer for creating box file for LSTM training.
+ *              based on the tsv renderer.
+ *
+ * (C) Copyright 2019, 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 <tesseract/baseapi.h>  // for TessBaseAPI
+#include <tesseract/renderer.h>
+#include "tesseractclass.h"  // for Tesseract
+
+namespace tesseract {
+
+/**
+ * Create a UTF8 box file for LSTM training from the internal data structures.
+ * page_number is a 0-base page index that will appear in the box file.
+ * Returned string must be freed with the delete [] operator.
+ */
+static void AddBoxToLSTM(int right, int bottom, int top, int image_height,
+                         int page_num, STRING* text) {
+  text->add_str_int(" ", image_height - bottom);
+  text->add_str_int(" ", right + 5);
+  text->add_str_int(" ", image_height - top);
+  text->add_str_int(" ", page_num);
+}
+
+char* TessBaseAPI::GetLSTMBoxText(int page_number=0) {
+  if (tesseract_ == nullptr || (page_res_ == nullptr && Recognize(nullptr) < 0))
+    return nullptr;
+
+  STRING lstm_box_str("");
+  bool first_word = true;
+  int left = 0, top = 0, right = 0, bottom = 0;
+
+  LTRResultIterator* res_it = GetLTRIterator();
+  while (!res_it->Empty(RIL_BLOCK)) {
+    if (res_it->Empty(RIL_SYMBOL)) {
+      res_it->Next(RIL_SYMBOL);
+      continue;
+    }
+    if (!first_word) {
+      if (!(res_it->IsAtBeginningOf(RIL_TEXTLINE))) {
+        if (res_it->IsAtBeginningOf(RIL_WORD)) {
+          lstm_box_str.add_str_int("  ", left);
+          AddBoxToLSTM(right, bottom, top, image_height_, page_number,
+                       &lstm_box_str);
+          lstm_box_str += "\n";  // end of row for word
+        }                        // word
+      } else {
+        if (res_it->IsAtBeginningOf(RIL_TEXTLINE)) {
+          lstm_box_str.add_str_int("\t ", left);
+          AddBoxToLSTM(right, bottom, top, image_height_, page_number,
+                       &lstm_box_str);
+          lstm_box_str += "\n";  // end of row for line
+        }                        // line
+      }
+    }  // not first word
+    first_word = false;
+    // Use bounding box for whole line for everything
+    res_it->BoundingBox(RIL_TEXTLINE, &left, &top, &right, &bottom);
+    do {
+      lstm_box_str +=
+          std::unique_ptr<const char[]>(res_it->GetUTF8Text(RIL_SYMBOL)).get();
+      res_it->Next(RIL_SYMBOL);
+    } while (!res_it->Empty(RIL_BLOCK) && !res_it->IsAtBeginningOf(RIL_SYMBOL));
+    lstm_box_str.add_str_int(" ", left);
+    AddBoxToLSTM(right, bottom, top, image_height_, page_number, &lstm_box_str);
+    lstm_box_str += "\n";  // end of row for symbol
+  }
+  if (!first_word) {  // if first_word is true  => empty page
+    lstm_box_str.add_str_int("\t ", left);
+    AddBoxToLSTM(right, bottom, top, image_height_, page_number, &lstm_box_str);
+    lstm_box_str += "\n";  // end of PAGE
+  }
+  char* ret = new char[lstm_box_str.length() + 1];
+  strcpy(ret, lstm_box_str.c_str());
+  delete res_it;
+  return ret;
+}
+
+/**********************************************************************
+ * LSTMBox Renderer interface implementation
+ **********************************************************************/
+TessLSTMBoxRenderer::TessLSTMBoxRenderer(const char* outputbase)
+    : TessResultRenderer(outputbase, "box") {}
+
+bool TessLSTMBoxRenderer::AddImageHandler(TessBaseAPI* api) {
+  const std::unique_ptr<const char[]> lstmbox(api->GetLSTMBoxText(imagenum()));
+  if (lstmbox == nullptr) return false;
+
+  AppendString(lstmbox.get());
+
+  return true;
+}
+
+}  // namespace tesseract.