tesseract  5.0.0
text2image.cpp
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1 /**********************************************************************
2  * File: text2image.cpp
3  * Description: Program to generate OCR training pages. Given a text file it
4  * outputs an image with a given font and degradation.
5  *
6  * Note that since the results depend on the fonts available on
7  * your system, running the code on a different machine, or
8  * different OS, or even at a different time on the same machine,
9  * may produce different fonts even if --font is given explicitly.
10  * To see names of available fonts, use --list_available_fonts with
11  * the appropriate --fonts_dir path.
12  * Specifying --use_only_legacy_fonts will restrict the available
13  * fonts to those listed in legacy_fonts.h
14  * Authors: Ranjith Unnikrishnan, Ray Smith
15  *
16  * (C) Copyright 2013, Google Inc.
17  * Licensed under the Apache License, Version 2.0 (the "License");
18  * you may not use this file except in compliance with the License.
19  * You may obtain a copy of the License at
20  * http://www.apache.org/licenses/LICENSE-2.0
21  * Unless required by applicable law or agreed to in writing, software
22  * distributed under the License is distributed on an "AS IS" BASIS,
23  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
24  * See the License for the specific language governing permissions and
25  * limitations under the License.
26  *
27  **********************************************************************/
28 
29 #include "boxchar.h"
30 #include "commandlineflags.h"
31 #include "commontraining.h" // CheckSharedLibraryVersion
32 #include "degradeimage.h"
33 #include "errcode.h"
34 #include "fileio.h"
35 #include "helpers.h"
36 #include "normstrngs.h"
37 #include "stringrenderer.h"
38 #include "tlog.h"
39 #include "unicharset.h"
40 
41 #include <allheaders.h> // from leptonica
42 
43 #include <algorithm>
44 #include <cstdlib>
45 #include <cstring>
46 #include <iostream>
47 #include <map>
48 #include <random>
49 #include <string>
50 #include <utility>
51 #include <vector>
52 
53 #ifdef _MSC_VER
54 # define putenv(s) _putenv(s)
55 #endif
56 
57 using namespace tesseract;
58 
59 // A number with which to initialize the random number generator.
60 const int kRandomSeed = 0x18273645;
61 
62 // The text input file.
63 static STRING_PARAM_FLAG(text, "", "File name of text input to process");
64 
65 // The text output file.
66 static STRING_PARAM_FLAG(outputbase, "", "Basename for output image/box file");
67 
68 // Degrade the rendered image to mimic scanner quality.
69 static BOOL_PARAM_FLAG(degrade_image, true,
70  "Degrade rendered image with speckle noise, dilation/erosion "
71  "and rotation");
72 
73 // Rotate the rendered image to have more realistic glyph borders
74 static BOOL_PARAM_FLAG(rotate_image, true, "Rotate the image in a random way.");
75 
76 // Degradation to apply to the image.
77 static INT_PARAM_FLAG(exposure, 0, "Exposure level in photocopier");
78 
79 // Distort the rendered image by various means according to the bool flags.
80 static BOOL_PARAM_FLAG(distort_image, false, "Degrade rendered image with noise, blur, invert.");
81 
82 // Distortion to apply to the image.
83 static BOOL_PARAM_FLAG(invert, true, "Invert the image");
84 
85 // Distortion to apply to the image.
86 static BOOL_PARAM_FLAG(white_noise, true, "Add Gaussian Noise");
87 
88 // Distortion to apply to the image.
89 static BOOL_PARAM_FLAG(smooth_noise, true, "Smoothen Noise");
90 
91 // Distortion to apply to the image.
92 static BOOL_PARAM_FLAG(blur, true, "Blur the image");
93 
94 #if 0
95 
96 // Distortion to apply to the image.
97 static BOOL_PARAM_FLAG(perspective, false, "Generate Perspective Distortion");
98 
99 // Distortion to apply to the image.
100 static INT_PARAM_FLAG(box_reduction, 0, "Integer reduction factor box_scale");
101 
102 #endif
103 
104 // Output image resolution.
105 static INT_PARAM_FLAG(resolution, 300, "Pixels per inch");
106 
107 // Width of output image (in pixels).
108 static INT_PARAM_FLAG(xsize, 3600, "Width of output image");
109 
110 // Max height of output image (in pixels).
111 static INT_PARAM_FLAG(ysize, 4800, "Height of output image");
112 
113 // Max number of pages to produce.
114 static INT_PARAM_FLAG(max_pages, 0, "Maximum number of pages to output (0=unlimited)");
115 
116 // Margin around text (in pixels).
117 static INT_PARAM_FLAG(margin, 100, "Margin round edges of image");
118 
119 // Size of text (in points).
120 static INT_PARAM_FLAG(ptsize, 12, "Size of printed text");
121 
122 // Inter-character space (in ems).
123 static DOUBLE_PARAM_FLAG(char_spacing, 0, "Inter-character space in ems");
124 
125 // Sets the probability (value in [0, 1]) of starting to render a word with an
126 // underline. Words are assumed to be space-delimited.
127 static DOUBLE_PARAM_FLAG(underline_start_prob, 0,
128  "Fraction of words to underline (value in [0,1])");
129 // Set the probability (value in [0, 1]) of continuing a started underline to
130 // the next word.
131 static DOUBLE_PARAM_FLAG(underline_continuation_prob, 0,
132  "Fraction of words to underline (value in [0,1])");
133 
134 // Inter-line space (in pixels).
135 static INT_PARAM_FLAG(leading, 12, "Inter-line space (in pixels)");
136 
137 // Layout and glyph orientation on rendering.
138 static STRING_PARAM_FLAG(writing_mode, "horizontal",
139  "Specify one of the following writing"
140  " modes.\n"
141  "'horizontal' : Render regular horizontal text. (default)\n"
142  "'vertical' : Render vertical text. Glyph orientation is"
143  " selected by Pango.\n"
144  "'vertical-upright' : Render vertical text. Glyph "
145  " orientation is set to be upright.");
146 
147 static INT_PARAM_FLAG(box_padding, 0, "Padding around produced bounding boxes");
148 
149 static BOOL_PARAM_FLAG(strip_unrenderable_words, true,
150  "Remove unrenderable words from source text");
151 
152 // Font name.
153 static STRING_PARAM_FLAG(font, "Arial", "Font description name to use");
154 
155 static BOOL_PARAM_FLAG(ligatures, false, "Rebuild and render ligatures");
156 
157 static BOOL_PARAM_FLAG(find_fonts, false, "Search for all fonts that can render the text");
158 static BOOL_PARAM_FLAG(render_per_font, true,
159  "If find_fonts==true, render each font to its own image. "
160  "Image filenames are of the form output_name.font_name.tif");
161 static DOUBLE_PARAM_FLAG(min_coverage, 1.0,
162  "If find_fonts==true, the minimum coverage the font has of "
163  "the characters in the text file to include it, between "
164  "0 and 1.");
165 
166 static BOOL_PARAM_FLAG(list_available_fonts, false, "List available fonts and quit.");
167 
168 static BOOL_PARAM_FLAG(render_ngrams, false,
169  "Put each space-separated entity from the"
170  " input file into one bounding box. The ngrams in the input"
171  " file will be randomly permuted before rendering (so that"
172  " there is sufficient variety of characters on each line).");
173 
174 static BOOL_PARAM_FLAG(output_word_boxes, false,
175  "Output word bounding boxes instead of character boxes. "
176  "This is used for Cube training, and implied by "
177  "--render_ngrams.");
178 
179 static STRING_PARAM_FLAG(unicharset_file, "",
180  "File with characters in the unicharset. If --render_ngrams"
181  " is true and --unicharset_file is specified, ngrams with"
182  " characters that are not in unicharset will be omitted");
183 
184 static BOOL_PARAM_FLAG(bidirectional_rotation, false, "Rotate the generated characters both ways.");
185 
186 static BOOL_PARAM_FLAG(only_extract_font_properties, false,
187  "Assumes that the input file contains a list of ngrams. Renders"
188  " each ngram, extracts spacing properties and records them in"
189  " output_base/[font_name].fontinfo file.");
190 
191 // Use these flags to output zero-padded, square individual character images
192 static BOOL_PARAM_FLAG(output_individual_glyph_images, false,
193  "If true also outputs individual character images");
194 static INT_PARAM_FLAG(glyph_resized_size, 0,
195  "Each glyph is square with this side length in pixels");
196 static INT_PARAM_FLAG(glyph_num_border_pixels_to_pad, 0,
197  "Final_size=glyph_resized_size+2*glyph_num_border_pixels_to_pad");
198 
199 namespace tesseract {
200 
203  SpacingProperties(int b, int a) : x_gap_before(b), x_gap_after(a) {}
204  // These values are obtained from FT_Glyph_Metrics struct
205  // used by the FreeType font engine.
206  int x_gap_before; // horizontal x bearing
207  int x_gap_after; // horizontal advance - x_gap_before - width
208  std::map<std::string, int> kerned_x_gaps;
209 };
210 
211 static bool IsWhitespaceBox(const BoxChar *boxchar) {
212  return (boxchar->box() == nullptr || SpanUTF8Whitespace(boxchar->ch().c_str()));
213 }
214 
215 static std::string StringReplace(const std::string &in, const std::string &oldsub,
216  const std::string &newsub) {
217  std::string out;
218  size_t start_pos = 0, pos;
219  while ((pos = in.find(oldsub, start_pos)) != std::string::npos) {
220  out.append(in.data() + start_pos, pos - start_pos);
221  out.append(newsub.data(), newsub.length());
222  start_pos = pos + oldsub.length();
223  }
224  out.append(in.data() + start_pos, in.length() - start_pos);
225  return out;
226 }
227 
228 // Assumes that each word (whitespace-separated entity) in text is a bigram.
229 // Renders the bigrams and calls FontInfo::GetSpacingProperties() to
230 // obtain spacing information. Produces the output .fontinfo file with a line
231 // per unichar of the form:
232 // unichar space_before space_after kerned1 kerned_space1 kerned2 ...
233 // Fox example, if unichar "A" has spacing of 0 pixels before and -1 pixels
234 // after, is kerned with "V" resulting in spacing of "AV" to be -7 and kerned
235 // with "T", such that "AT" has spacing of -5, the entry/line for unichar "A"
236 // in .fontinfo file will be:
237 // A 0 -1 T -5 V -7
238 static void ExtractFontProperties(const std::string &utf8_text, StringRenderer *render,
239  const std::string &output_base) {
240  std::map<std::string, SpacingProperties> spacing_map;
241  std::map<std::string, SpacingProperties>::iterator spacing_map_it0;
242  std::map<std::string, SpacingProperties>::iterator spacing_map_it1;
243  int x_bearing, x_advance;
244  int len = utf8_text.length();
245  int offset = 0;
246  const char *text = utf8_text.c_str();
247  while (offset < len) {
248  offset += render->RenderToImage(text + offset, strlen(text + offset), nullptr);
249  const std::vector<BoxChar *> &boxes = render->GetBoxes();
250 
251  // If the page break split a bigram, correct the offset so we try the bigram
252  // on the next iteration.
253  if (boxes.size() > 2 && !IsWhitespaceBox(boxes[boxes.size() - 1]) &&
254  IsWhitespaceBox(boxes[boxes.size() - 2])) {
255  if (boxes.size() > 3) {
256  tprintf("WARNING: Adjusting to bad page break after '%s%s'\n",
257  boxes[boxes.size() - 4]->ch().c_str(), boxes[boxes.size() - 3]->ch().c_str());
258  }
259  offset -= boxes[boxes.size() - 1]->ch().size();
260  }
261 
262  for (size_t b = 0; b < boxes.size(); b += 2) {
263  while (b < boxes.size() && IsWhitespaceBox(boxes[b])) {
264  ++b;
265  }
266  if (b + 1 >= boxes.size()) {
267  break;
268  }
269  const std::string &ch0 = boxes[b]->ch();
270  // We encountered a ligature. This happens in at least two scenarios:
271  // One is when the rendered bigram forms a grapheme cluster (eg. the
272  // second character in the bigram is a combining vowel), in which case we
273  // correctly output only one bounding box.
274  // A second far less frequent case is when caused some fonts like 'DejaVu
275  // Sans Ultra-Light' force Pango to render a ligatured character even if
276  // the input consists of the separated characters. NOTE(ranjith): As per
277  // behdad@ this is not currently controllable at the level of the Pango
278  // API.
279  // The most frequent of all is a single character "word" made by the CJK
280  // segmenter.
281  // Safeguard against these cases here by just skipping the bigram.
282  if (IsWhitespaceBox(boxes[b + 1])) {
283  continue;
284  }
285  int xgap = (boxes[b + 1]->box()->x - (boxes[b]->box()->x + boxes[b]->box()->w));
286  spacing_map_it0 = spacing_map.find(ch0);
287  int ok_count = 0;
288  if (spacing_map_it0 == spacing_map.end() &&
289  render->font().GetSpacingProperties(ch0, &x_bearing, &x_advance)) {
290  spacing_map[ch0] = SpacingProperties(x_bearing, x_advance - x_bearing - boxes[b]->box()->w);
291  spacing_map_it0 = spacing_map.find(ch0);
292  ++ok_count;
293  }
294  const std::string &ch1 = boxes[b + 1]->ch();
295  tlog(3, "%s%s\n", ch0.c_str(), ch1.c_str());
296  spacing_map_it1 = spacing_map.find(ch1);
297  if (spacing_map_it1 == spacing_map.end() &&
298  render->font().GetSpacingProperties(ch1, &x_bearing, &x_advance)) {
299  spacing_map[ch1] =
300  SpacingProperties(x_bearing, x_advance - x_bearing - boxes[b + 1]->box()->w);
301  spacing_map_it1 = spacing_map.find(ch1);
302  ++ok_count;
303  }
304  if (ok_count == 2 &&
305  xgap != (spacing_map_it0->second.x_gap_after + spacing_map_it1->second.x_gap_before)) {
306  spacing_map_it0->second.kerned_x_gaps[ch1] = xgap;
307  }
308  }
309  render->ClearBoxes();
310  }
311  std::string output_string;
312  const int kBufSize = 1024;
313  char buf[kBufSize];
314  snprintf(buf, kBufSize, "%d\n", static_cast<int>(spacing_map.size()));
315  output_string.append(buf);
316  std::map<std::string, SpacingProperties>::const_iterator spacing_map_it;
317  for (spacing_map_it = spacing_map.begin(); spacing_map_it != spacing_map.end();
318  ++spacing_map_it) {
319  snprintf(buf, kBufSize, "%s %d %d %d", spacing_map_it->first.c_str(),
320  spacing_map_it->second.x_gap_before, spacing_map_it->second.x_gap_after,
321  static_cast<int>(spacing_map_it->second.kerned_x_gaps.size()));
322  output_string.append(buf);
323  std::map<std::string, int>::const_iterator kern_it;
324  for (kern_it = spacing_map_it->second.kerned_x_gaps.begin();
325  kern_it != spacing_map_it->second.kerned_x_gaps.end(); ++kern_it) {
326  snprintf(buf, kBufSize, " %s %d", kern_it->first.c_str(), kern_it->second);
327  output_string.append(buf);
328  }
329  output_string.append("\n");
330  }
331  File::WriteStringToFileOrDie(output_string, output_base + ".fontinfo");
332 }
333 
334 static bool MakeIndividualGlyphs(Image pix, const std::vector<BoxChar *> &vbox,
335  const int input_tiff_page) {
336  // If checks fail, return false without exiting text2image
337  if (!pix) {
338  tprintf("ERROR: MakeIndividualGlyphs(): Input Pix* is nullptr\n");
339  return false;
340  } else if (FLAGS_glyph_resized_size <= 0) {
341  tprintf("ERROR: --glyph_resized_size must be positive\n");
342  return false;
343  } else if (FLAGS_glyph_num_border_pixels_to_pad < 0) {
344  tprintf("ERROR: --glyph_num_border_pixels_to_pad must be 0 or positive\n");
345  return false;
346  }
347 
348  const int n_boxes = vbox.size();
349  int n_boxes_saved = 0;
350  int current_tiff_page = 0;
351  int y_previous = 0;
352  static int glyph_count = 0;
353  for (int i = 0; i < n_boxes; i++) {
354  // Get one bounding box
355  Box *b = vbox[i]->mutable_box();
356  if (!b) {
357  continue;
358  }
359  const int x = b->x;
360  const int y = b->y;
361  const int w = b->w;
362  const int h = b->h;
363  // Check present tiff page (for multipage tiff)
364  if (y < y_previous - pixGetHeight(pix) / 10) {
365  tprintf("ERROR: Wrap-around encountered, at i=%d\n", i);
366  current_tiff_page++;
367  }
368  if (current_tiff_page < input_tiff_page) {
369  continue;
370  } else if (current_tiff_page > input_tiff_page) {
371  break;
372  }
373  // Check box validity
374  if (x < 0 || y < 0 || (x + w - 1) >= pixGetWidth(pix) || (y + h - 1) >= pixGetHeight(pix)) {
375  tprintf(
376  "ERROR: MakeIndividualGlyphs(): Index out of range, at i=%d"
377  " (x=%d, y=%d, w=%d, h=%d\n)",
378  i, x, y, w, h);
379  continue;
380  } else if (w < FLAGS_glyph_num_border_pixels_to_pad &&
381  h < FLAGS_glyph_num_border_pixels_to_pad) {
382  tprintf("ERROR: Input image too small to be a character, at i=%d\n", i);
383  continue;
384  }
385  // Crop the boxed character
386  Image pix_glyph = pixClipRectangle(pix, b, nullptr);
387  if (!pix_glyph) {
388  tprintf("ERROR: MakeIndividualGlyphs(): Failed to clip, at i=%d\n", i);
389  continue;
390  }
391  // Resize to square
392  Image pix_glyph_sq =
393  pixScaleToSize(pix_glyph, FLAGS_glyph_resized_size, FLAGS_glyph_resized_size);
394  if (!pix_glyph_sq) {
395  tprintf("ERROR: MakeIndividualGlyphs(): Failed to resize, at i=%d\n", i);
396  continue;
397  }
398  // Zero-pad
399  Image pix_glyph_sq_pad = pixAddBorder(pix_glyph_sq, FLAGS_glyph_num_border_pixels_to_pad, 0);
400  if (!pix_glyph_sq_pad) {
401  tprintf("ERROR: MakeIndividualGlyphs(): Failed to zero-pad, at i=%d\n", i);
402  continue;
403  }
404  // Write out
405  Image pix_glyph_sq_pad_8 = pixConvertTo8(pix_glyph_sq_pad, false);
406  char filename[1024];
407  snprintf(filename, 1024, "%s_%d.jpg", FLAGS_outputbase.c_str(), glyph_count++);
408  if (pixWriteJpeg(filename, pix_glyph_sq_pad_8, 100, 0)) {
409  tprintf(
410  "ERROR: MakeIndividualGlyphs(): Failed to write JPEG to %s,"
411  " at i=%d\n",
412  filename, i);
413  continue;
414  }
415 
416  pix_glyph.destroy();
417  pix_glyph_sq.destroy();
418  pix_glyph_sq_pad.destroy();
419  pix_glyph_sq_pad_8.destroy();
420  n_boxes_saved++;
421  y_previous = y;
422  }
423  if (n_boxes_saved == 0) {
424  return false;
425  } else {
426  tprintf("Total number of characters saved = %d\n", n_boxes_saved);
427  return true;
428  }
429 }
430 } // namespace tesseract
431 
433 using tesseract::ExtractFontProperties;
434 using tesseract::File;
439 
440 static int Main() {
441  if (FLAGS_list_available_fonts) {
442  const std::vector<std::string> &all_fonts = FontUtils::ListAvailableFonts();
443  for (unsigned int i = 0; i < all_fonts.size(); ++i) {
444  // Remove trailing comma: pango-font-description-to-string adds a comma
445  // to some fonts.
446  // See https://github.com/tesseract-ocr/tesseract/issues/408
447  std::string font_name(all_fonts[i].c_str());
448  if (font_name.back() == ',') {
449  font_name.pop_back();
450  }
451  printf("%3u: %s\n", i, font_name.c_str());
452  ASSERT_HOST_MSG(FontUtils::IsAvailableFont(all_fonts[i].c_str()),
453  "Font %s is unrecognized.\n", all_fonts[i].c_str());
454  }
455  return EXIT_SUCCESS;
456  }
457 
458  // Check validity of input flags.
459  if (FLAGS_text.empty()) {
460  tprintf("'--text' option is missing!\n");
461  exit(1);
462  }
463  if (FLAGS_outputbase.empty()) {
464  tprintf("'--outputbase' option is missing!\n");
465  exit(1);
466  }
467  if (!FLAGS_unicharset_file.empty() && FLAGS_render_ngrams) {
468  tprintf("Use '--unicharset_file' only if '--render_ngrams' is set.\n");
469  exit(1);
470  }
471 
472  std::string font_name = FLAGS_font.c_str();
473  if (!FLAGS_find_fonts && !FontUtils::IsAvailableFont(font_name.c_str())) {
474  font_name += ',';
475  std::string pango_name;
476  if (!FontUtils::IsAvailableFont(font_name.c_str(), &pango_name)) {
477  tprintf("Could not find font named '%s'.\n", FLAGS_font.c_str());
478  if (!pango_name.empty()) {
479  tprintf("Pango suggested font '%s'.\n", pango_name.c_str());
480  }
481  tprintf("Please correct --font arg.\n");
482  exit(1);
483  }
484  }
485 
486  if (FLAGS_render_ngrams) {
487  FLAGS_output_word_boxes = true;
488  }
489 
490  char font_desc_name[1024];
491  snprintf(font_desc_name, 1024, "%s %d", font_name.c_str(), static_cast<int>(FLAGS_ptsize));
492 
493  StringRenderer render(font_desc_name, FLAGS_xsize, FLAGS_ysize);
494  render.set_add_ligatures(FLAGS_ligatures);
495  render.set_leading(FLAGS_leading);
496  render.set_resolution(FLAGS_resolution);
497  render.set_char_spacing(FLAGS_char_spacing * FLAGS_ptsize);
498  render.set_h_margin(FLAGS_margin);
499  render.set_v_margin(FLAGS_margin);
500  render.set_output_word_boxes(FLAGS_output_word_boxes);
501  render.set_box_padding(FLAGS_box_padding);
502  render.set_strip_unrenderable_words(FLAGS_strip_unrenderable_words);
503  render.set_underline_start_prob(FLAGS_underline_start_prob);
504  render.set_underline_continuation_prob(FLAGS_underline_continuation_prob);
505 
506  // Set text rendering orientation and their forms.
507  if (FLAGS_writing_mode == "horizontal") {
508  // Render regular horizontal text (default).
509  render.set_vertical_text(false);
510  render.set_gravity_hint_strong(false);
511  render.set_render_fullwidth_latin(false);
512  } else if (FLAGS_writing_mode == "vertical") {
513  // Render vertical text. Glyph orientation is selected by Pango.
514  render.set_vertical_text(true);
515  render.set_gravity_hint_strong(false);
516  render.set_render_fullwidth_latin(false);
517  } else if (FLAGS_writing_mode == "vertical-upright") {
518  // Render vertical text. Glyph orientation is set to be upright.
519  // Also Basic Latin characters are converted to their fullwidth forms
520  // on rendering, since fullwidth Latin characters are well designed to fit
521  // vertical text lines, while .box files store halfwidth Basic Latin
522  // unichars.
523  render.set_vertical_text(true);
524  render.set_gravity_hint_strong(true);
525  render.set_render_fullwidth_latin(true);
526  } else {
527  tprintf("Invalid writing mode: %s\n", FLAGS_writing_mode.c_str());
528  exit(1);
529  }
530 
531  std::string src_utf8;
532  // This c_str is NOT redundant!
533  if (!File::ReadFileToString(FLAGS_text.c_str(), &src_utf8)) {
534  tprintf("Failed to read file: %s\n", FLAGS_text.c_str());
535  exit(1);
536  }
537 
538  // Remove the unicode mark if present.
539  if (strncmp(src_utf8.c_str(), "\xef\xbb\xbf", 3) == 0) {
540  src_utf8.erase(0, 3);
541  }
542  tlog(1, "Render string of size %zu\n", src_utf8.length());
543 
544  if (FLAGS_render_ngrams || FLAGS_only_extract_font_properties) {
545  // Try to preserve behavior of old text2image by expanding inter-word
546  // spaces by a factor of 4.
547  const std::string kSeparator = FLAGS_render_ngrams ? " " : " ";
548  // Also restrict the number of characters per line to try and avoid
549  // line-breaking in the middle of words like "-A", "R$" etc. which are
550  // otherwise allowed by the standard unicode line-breaking rules.
551  const unsigned int kCharsPerLine = (FLAGS_ptsize > 20) ? 50 : 100;
552  std::string rand_utf8;
553  UNICHARSET unicharset;
554  if (FLAGS_render_ngrams && !FLAGS_unicharset_file.empty() &&
555  !unicharset.load_from_file(FLAGS_unicharset_file.c_str())) {
556  tprintf("Failed to load unicharset from file %s\n", FLAGS_unicharset_file.c_str());
557  exit(1);
558  }
559 
560  // If we are rendering ngrams that will be OCRed later, shuffle them so that
561  // tesseract does not have difficulties finding correct baseline, word
562  // spaces, etc.
563  const char *str8 = src_utf8.c_str();
564  int len = src_utf8.length();
565  int step;
566  std::vector<std::pair<int, int>> offsets;
567  int offset = SpanUTF8Whitespace(str8);
568  while (offset < len) {
569  step = SpanUTF8NotWhitespace(str8 + offset);
570  offsets.emplace_back(offset, step);
571  offset += step;
572  offset += SpanUTF8Whitespace(str8 + offset);
573  }
574  if (FLAGS_render_ngrams) {
575  std::seed_seq seed{kRandomSeed};
576  std::mt19937 random_gen(seed);
577  std::shuffle(offsets.begin(), offsets.end(), random_gen);
578  }
579 
580  for (size_t i = 0, line = 1; i < offsets.size(); ++i) {
581  const char *curr_pos = str8 + offsets[i].first;
582  int ngram_len = offsets[i].second;
583  // Skip words that contain characters not in found in unicharset.
584  std::string cleaned = UNICHARSET::CleanupString(curr_pos, ngram_len);
585  if (!FLAGS_unicharset_file.empty() &&
586  !unicharset.encodable_string(cleaned.c_str(), nullptr)) {
587  continue;
588  }
589  rand_utf8.append(curr_pos, ngram_len);
590  if (rand_utf8.length() > line * kCharsPerLine) {
591  rand_utf8.append(" \n");
592  ++line;
593  if (line & 0x1) {
594  rand_utf8.append(kSeparator);
595  }
596  } else {
597  rand_utf8.append(kSeparator);
598  }
599  }
600  tlog(1, "Rendered ngram string of size %zu\n", rand_utf8.length());
601  src_utf8.swap(rand_utf8);
602  }
603  if (FLAGS_only_extract_font_properties) {
604  tprintf("Extracting font properties only\n");
605  ExtractFontProperties(src_utf8, &render, FLAGS_outputbase.c_str());
606  tprintf("Done!\n");
607  return 0;
608  }
609 
610  int im = 0;
611  std::vector<float> page_rotation;
612  const char *to_render_utf8 = src_utf8.c_str();
613 
614  tesseract::TRand randomizer;
615  randomizer.set_seed(kRandomSeed);
616  std::vector<std::string> font_names;
617  // We use a two pass mechanism to rotate images in both direction.
618  // The first pass(0) will rotate the images in random directions and
619  // the second pass(1) will mirror those rotations.
620  int num_pass = FLAGS_bidirectional_rotation ? 2 : 1;
621  for (int pass = 0; pass < num_pass; ++pass) {
622  int page_num = 0;
623  std::string font_used;
624  for (size_t offset = 0;
625  offset < strlen(to_render_utf8) && (FLAGS_max_pages == 0 || page_num < FLAGS_max_pages);
626  ++im, ++page_num) {
627  tlog(1, "Starting page %d\n", im);
628  Image pix = nullptr;
629  if (FLAGS_find_fonts) {
630  offset += render.RenderAllFontsToImage(FLAGS_min_coverage, to_render_utf8 + offset,
631  strlen(to_render_utf8 + offset), &font_used, &pix);
632  } else {
633  offset +=
634  render.RenderToImage(to_render_utf8 + offset, strlen(to_render_utf8 + offset), &pix);
635  }
636  if (pix != nullptr) {
637  float rotation = 0;
638  if (pass == 1) {
639  // Pass 2, do mirror rotation.
640  rotation = -1 * page_rotation[page_num];
641  }
642  if (FLAGS_degrade_image) {
643  pix = DegradeImage(pix, FLAGS_exposure, &randomizer,
644  FLAGS_rotate_image ? &rotation : nullptr);
645  }
646  if (FLAGS_distort_image) {
647  // TODO: perspective is set to false and box_reduction to 1.
648  pix = PrepareDistortedPix(pix, false, FLAGS_invert, FLAGS_white_noise, FLAGS_smooth_noise,
649  FLAGS_blur, 1, &randomizer, nullptr);
650  }
651  render.RotatePageBoxes(rotation);
652 
653  if (pass == 0) {
654  // Pass 1, rotate randomly and store the rotation..
655  page_rotation.push_back(rotation);
656  }
657 
658  Image gray_pix = pixConvertTo8(pix, false);
659  pix.destroy();
660  Image binary = pixThresholdToBinary(gray_pix, 128);
661  gray_pix.destroy();
662  char tiff_name[1024];
663  if (FLAGS_find_fonts) {
664  if (FLAGS_render_per_font) {
665  std::string fontname_for_file = tesseract::StringReplace(font_used, " ", "_");
666  snprintf(tiff_name, 1024, "%s.%s.tif", FLAGS_outputbase.c_str(),
667  fontname_for_file.c_str());
668  pixWriteTiff(tiff_name, binary, IFF_TIFF_G4, "w");
669  tprintf("Rendered page %d to file %s\n", im, tiff_name);
670  } else {
671  font_names.push_back(font_used);
672  }
673  } else {
674  snprintf(tiff_name, 1024, "%s.tif", FLAGS_outputbase.c_str());
675  pixWriteTiff(tiff_name, binary, IFF_TIFF_G4, im == 0 ? "w" : "a");
676  tprintf("Rendered page %d to file %s\n", im, tiff_name);
677  }
678  // Make individual glyphs
679  if (FLAGS_output_individual_glyph_images) {
680  if (!MakeIndividualGlyphs(binary, render.GetBoxes(), im)) {
681  tprintf("ERROR: Individual glyphs not saved\n");
682  }
683  }
684  binary.destroy();
685  }
686  if (FLAGS_find_fonts && offset != 0) {
687  // We just want a list of names, or some sample images so we don't need
688  // to render more than the first page of the text.
689  break;
690  }
691  }
692  }
693  if (!FLAGS_find_fonts) {
694  std::string box_name = FLAGS_outputbase.c_str();
695  box_name += ".box";
696  render.WriteAllBoxes(box_name);
697  } else if (!FLAGS_render_per_font && !font_names.empty()) {
698  std::string filename = FLAGS_outputbase.c_str();
699  filename += ".fontlist.txt";
700  FILE *fp = fopen(filename.c_str(), "wb");
701  if (fp == nullptr) {
702  tprintf("Failed to create output font list %s\n", filename.c_str());
703  } else {
704  for (auto &font_name : font_names) {
705  fprintf(fp, "%s\n", font_name.c_str());
706  }
707  fclose(fp);
708  }
709  }
710 
711  return 0;
712 }
713 
714 int main(int argc, char **argv) {
715  // Respect environment variable. could be:
716  // fc (fontconfig), win32, and coretext
717  // If not set force fontconfig for Mac OS.
718  // See https://github.com/tesseract-ocr/tesseract/issues/736
719  char *backend;
720  backend = getenv("PANGOCAIRO_BACKEND");
721  if (backend == nullptr) {
722  static char envstring[] = "PANGOCAIRO_BACKEND=fc";
723  putenv(envstring);
724  } else {
725  printf(
726  "Using '%s' as pango cairo backend based on environment "
727  "variable.\n",
728  backend);
729  }
730  tesseract::CheckSharedLibraryVersion();
731  if (argc > 1) {
732  if ((strcmp(argv[1], "-v") == 0) || (strcmp(argv[1], "--version") == 0)) {
734  printf("Pango version: %s\n", pango_version_string());
735  }
736  }
737  tesseract::ParseCommandLineFlags(argv[0], &argc, &argv, true);
738  return Main();
739 }
#define ASSERT_HOST_MSG(x,...)
Definition: errcode.h:62
#define DOUBLE_PARAM_FLAG(name, val, comment)
#define BOOL_PARAM_FLAG(name, val, comment)
#define STRING_PARAM_FLAG(name, val, comment)
#define tlog(level,...)
Definition: tlog.h:36
int main(int argc, char **argv)
Definition: text2image.cpp:714
const int kRandomSeed
Definition: text2image.cpp:60
void ParseCommandLineFlags(const char *usage, int *argc, char ***argv, const bool remove_flags)
unsigned int SpanUTF8Whitespace(const char *text)
Definition: normstrngs.cpp:237
void tprintf(const char *format,...)
Definition: tprintf.cpp:41
Image PrepareDistortedPix(const Image pix, bool perspective, bool invert, bool white_noise, bool smooth_noise, bool blur, int box_reduction, TRand *randomizer, std::vector< TBOX > *boxes)
INT_PARAM_FLAG(debug_level, 0, "Level of Trainer debugging")
Image DegradeImage(Image input, int exposure, TRand *randomizer, float *rotation)
unsigned int SpanUTF8NotWhitespace(const char *text)
Definition: normstrngs.cpp:249
void destroy()
Definition: image.cpp:32
void set_seed(uint64_t seed)
Definition: helpers.h:62
bool encodable_string(const char *str, unsigned *first_bad_position) const
Definition: unicharset.cpp:224
bool load_from_file(const char *const filename, bool skip_fragments)
Definition: unicharset.h:391
static std::string CleanupString(const char *utf8_str)
Definition: unicharset.h:265
const std::string & ch() const
Definition: boxchar.h:43
const Box * box() const
Definition: boxchar.h:46
bool GetSpacingProperties(const std::string &utf8_char, int *x_bearing, int *x_advance) const
static bool IsAvailableFont(const char *font_desc)
static void PangoFontTypeInfo()
static const std::vector< std::string > & ListAvailableFonts()
int RenderToImage(const char *text, int text_length, Image *pix)
void set_underline_start_prob(const double frac)
void set_vertical_text(bool vertical_text)
int RenderAllFontsToImage(double min_coverage, const char *text, int text_length, std::string *font_used, Image *pix)
void set_render_fullwidth_latin(bool render_fullwidth_latin)
const std::vector< BoxChar * > & GetBoxes() const
void set_gravity_hint_strong(bool gravity_hint_strong)
void set_resolution(const int resolution)
void set_underline_continuation_prob(const double frac)
void set_strip_unrenderable_words(bool val)
void set_add_ligatures(bool add_ligatures)
void set_h_margin(const int h_margin)
void set_char_spacing(int char_spacing)
void set_output_word_boxes(bool val)
void set_v_margin(const int v_margin)
const PangoFontInfo & font() const
void WriteAllBoxes(const std::string &filename)
void RotatePageBoxes(float rotation)
void set_leading(int leading)
std::map< std::string, int > kerned_x_gaps
Definition: text2image.cpp:208
static bool ReadFileToString(const std::string &filename, std::string *out)
Definition: fileio.cpp:73
static void WriteStringToFileOrDie(const std::string &str, const std::string &filename)
Definition: fileio.cpp:54