diff --git a/.gitignore b/.gitignore index ea31e7e..ade5785 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,4 @@ pdf/* images/* audio/* +scripts/venv/* diff --git a/scripts/hocrtransform.py b/scripts/hocrtransform.py new file mode 100755 index 0000000..63a3cd7 --- /dev/null +++ b/scripts/hocrtransform.py @@ -0,0 +1,500 @@ +#!/usr/bin/env python3 +# +# Copyright (c) 2010, Jonathan Brinley +# Original version from: https://github.com/jbrinley/HocrConverter +# +# Copyright (c) 2013-14, Julien Pfefferkorn +# Modifications +# +# Copyright (c) 2015-16, James R. Barlow +# Set text to transparent +# +# Permission is hereby granted, free of charge, to any person obtaining a +# copy of this software and associated documentation files (the +# "Software"), to deal in the Software without restriction, including +# without limitation the rights to use, copy, modify, merge, publish, +# distribute, sublicense, and/or sell copies of the Software, and to +# permit persons to whom the Software is furnished to do so, subject to +# the following conditions: +# +# The above copyright notice and this permission notice shall be included +# in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +import argparse +import os +import re +from itertools import chain +from math import atan, cos, sin +from pathlib import Path +from typing import Any, NamedTuple, Optional, Tuple, Union +from xml.etree import ElementTree + +from reportlab.lib.colors import black, cyan, magenta, red +from reportlab.lib.units import inch +from reportlab.pdfgen.canvas import Canvas + +# According to Wikipedia these languages are supported in the ISO-8859-1 character +# set, meaning reportlab can generate them and they are compatible with hocr, +# assuming Tesseract has the necessary languages installed. Note that there may +# not be language packs for them. +HOCR_OK_LANGS = frozenset( + [ + # Languages fully covered by Latin-1: + 'afr', # Afrikaans + 'alb', # Albanian + 'ast', # Leonese + 'baq', # Basque + 'bre', # Breton + 'cos', # Corsican + 'eng', # English + 'eus', # Basque + 'fao', # Faoese + 'gla', # Scottish Gaelic + 'glg', # Galician + 'glv', # Manx + 'ice', # Icelandic + 'ind', # Indonesian + 'isl', # Icelandic + 'ita', # Italian + 'ltz', # Luxembourgish + 'mal', # Malay Rumi + 'mga', # Irish + 'nor', # Norwegian + 'oci', # Occitan + 'por', # Portugeuse + 'roh', # Romansh + 'sco', # Scots + 'sma', # Sami + 'spa', # Spanish + 'sqi', # Albanian + 'swa', # Swahili + 'swe', # Swedish + 'tgl', # Tagalog + 'wln', # Walloon + # Languages supported by Latin-1 except for a few rare characters that OCR + # is probably not trained to recognize anyway: + 'cat', # Catalan + 'cym', # Welsh + 'dan', # Danish + 'deu', # German + 'dut', # Dutch + 'est', # Estonian + 'fin', # Finnish + 'fra', # French + 'hun', # Hungarian + 'kur', # Kurdish + 'nld', # Dutch + 'wel', # Welsh + ] +) + + +Element = ElementTree.Element + + +class Rect(NamedTuple): # pylint: disable=inherit-non-class + """A rectangle for managing PDF coordinates.""" + + x1: Any + y1: Any + x2: Any + y2: Any + + +class HocrTransformError(Exception): + pass + + +class HocrTransform: + + """ + A class for converting documents from the hOCR format. + For details of the hOCR format, see: + http://kba.cloud/hocr-spec/ + """ + + box_pattern = re.compile(r'bbox((\s+\d+){4})') + baseline_pattern = re.compile( + r''' + baseline \s+ + ([\-\+]?\d*\.?\d*) \s+ # +/- decimal float + ([\-\+]?\d+) # +/- int''', + re.VERBOSE, + ) + ligatures = str.maketrans( + {'ff': 'ff', 'ffi': 'f‌f‌i', 'ffl': 'f‌f‌l', 'fi': 'fi', 'fl': 'fl'} + ) + + def __init__(self, *, hocr_filename: Union[str, Path], dpi: float): + self.dpi = dpi + self.hocr = ElementTree.parse(os.fspath(hocr_filename)) + + # if the hOCR file has a namespace, ElementTree requires its use to + # find elements + matches = re.match(r'({.*})html', self.hocr.getroot().tag) + self.xmlns = '' + if matches: + self.xmlns = matches.group(1) + + # get dimension in pt (not pixel!!!!) of the OCRed image + self.width, self.height = None, None + for div in self.hocr.findall(self._child_xpath('div', 'ocr_page')): + coords = self.element_coordinates(div) + pt_coords = self.pt_from_pixel(coords) + self.width = pt_coords.x2 - pt_coords.x1 + self.height = pt_coords.y2 - pt_coords.y1 + # there shouldn't be more than one, and if there is, we don't want + # it + break + if self.width is None or self.height is None: + raise HocrTransformError("hocr file is missing page dimensions") + + def __str__(self): # pragma: no cover + """ + Return the textual content of the HTML body + """ + if self.hocr is None: + return '' + body = self.hocr.find(self._child_xpath('body')) + if body: + return self._get_element_text(body) + else: + return '' + + def _get_element_text(self, element: Element): + """ + Return the textual content of the element and its children + """ + text = '' + if element.text is not None: + text += element.text + for child in element: + text += self._get_element_text(child) + if element.tail is not None: + text += element.tail + return text + + @classmethod + def element_coordinates(cls, element: Element) -> Rect: + """ + Returns a tuple containing the coordinates of the bounding box around + an element + """ + out = Rect._make(0 for _ in range(4)) + if 'title' in element.attrib: + matches = cls.box_pattern.search(element.attrib['title']) + if matches: + coords = matches.group(1).split() + out = Rect._make(int(coords[n]) for n in range(4)) + return out + + @classmethod + def baseline(cls, element: Element) -> Tuple[float, float]: + """ + Returns a tuple containing the baseline slope and intercept. + """ + if 'title' in element.attrib: + matches = cls.baseline_pattern.search(element.attrib['title']) + if matches: + return float(matches.group(1)), int(matches.group(2)) + return (0.0, 0.0) + + def pt_from_pixel(self, pxl) -> Rect: + """ + Returns the quantity in PDF units (pt) given quantity in pixels + """ + return Rect._make((c / self.dpi * inch) for c in pxl) + + def _child_xpath(self, html_tag: str, html_class: Optional[str] = None) -> str: + xpath = f".//{self.xmlns}{html_tag}" + if html_class: + xpath += f"[@class='{html_class}']" + return xpath + + @classmethod + def replace_unsupported_chars(cls, s: str) -> str: + """ + Given an input string, returns the corresponding string that: + * is available in the Helvetica facetype + * does not contain any ligature (to allow easy search in the PDF file) + """ + return s.translate(cls.ligatures) + + def topdown_position(self, element): + pxl_line_coords = self.element_coordinates(element) + line_box = self.pt_from_pixel(pxl_line_coords) + # Coordinates here are still in the hocr coordinate system, so 0 on the y axis + # is the top of the page and increasing values of y will move towards the + # bottom of the page. + return line_box.y2 + + def to_pdf( + self, + *, + out_filename: Path, + image_filename: Optional[Path] = None, + show_bounding_boxes: bool = False, + fontname: str = "Helvetica", + invisible_text: bool = False, + interword_spaces: bool = False, + ) -> None: + """ + Creates a PDF file with an image superimposed on top of the text. + Text is positioned according to the bounding box of the lines in + the hOCR file. + The image need not be identical to the image used to create the hOCR + file. + It can have a lower resolution, different color mode, etc. + + Arguments: + out_filename: Path of PDF to write. + image_filename: Image to use for this file. If omitted, the OCR text + is shown. + show_bounding_boxes: Show bounding boxes around various text regions, + for debugging. + fontname: Name of font to use. + invisible_text: If True, text is rendered invisible so that is + selectable but never drawn. If False, text is visible and may + be seen if the image is skipped or deleted in Acrobat. + interword_spaces: If True, insert spaces between words rather than + drawing each word without spaces. Generally this improves text + extraction. + """ + # create the PDF file + # page size in points (1/72 in.) + pdf = Canvas( + os.fspath(out_filename), + pagesize=(self.width, self.height), + pageCompression=1, + ) + + # draw bounding box for each paragraph + # light blue for bounding box of paragraph + pdf.setStrokeColor(cyan) + # light blue for bounding box of paragraph + pdf.setFillColor(cyan) + pdf.setLineWidth(0) # no line for bounding box + for elem in self.hocr.iterfind(self._child_xpath('p', 'ocr_par')): + elemtxt = self._get_element_text(elem).rstrip() + if len(elemtxt) == 0: + continue + + pxl_coords = self.element_coordinates(elem) + pt = self.pt_from_pixel(pxl_coords) + + # draw the bbox border + if show_bounding_boxes: # pragma: no cover + pdf.rect( + pt.x1, self.height - pt.y2, pt.x2 - pt.x1, pt.y2 - pt.y1, fill=1 + ) + + found_lines = False + for line in sorted( + chain( + self.hocr.iterfind(self._child_xpath('span', 'ocr_header')), + self.hocr.iterfind(self._child_xpath('span', 'ocr_line')), + self.hocr.iterfind(self._child_xpath('span', 'ocr_textfloat')), + ), + key=self.topdown_position, + ): + found_lines = True + self._do_line( + pdf, + line, + "ocrx_word", + fontname, + invisible_text, + interword_spaces, + show_bounding_boxes, + ) + + if not found_lines: + # Tesseract did not report any lines (just words) + root = self.hocr.find(self._child_xpath('div', 'ocr_page')) + self._do_line( + pdf, + root, + "ocrx_word", + fontname, + invisible_text, + interword_spaces, + show_bounding_boxes, + ) + # put the image on the page, scaled to fill the page + if image_filename is not None: + pdf.drawImage( + os.fspath(image_filename), 0, 0, width=self.width, height=self.height + ) + + # finish up the page and save it + pdf.showPage() + pdf.save() + + @classmethod + def polyval(cls, poly, x): # pragma: no cover + return x * poly[0] + poly[1] + + def _do_line( + self, + pdf: Canvas, + line: Optional[Element], + elemclass: str, + fontname: str, + invisible_text: bool, + interword_spaces: bool, + show_bounding_boxes: bool, + ): + if not line: + return + pxl_line_coords = self.element_coordinates(line) + line_box = self.pt_from_pixel(pxl_line_coords) + line_height = line_box.y2 - line_box.y1 + + slope, pxl_intercept = self.baseline(line) + if abs(slope) < 0.005: + slope = 0.0 + angle = atan(slope) + cos_a, sin_a = cos(angle), sin(angle) + + text = pdf.beginText() + intercept = pxl_intercept / self.dpi * inch + + # Don't allow the font to break out of the bounding box. Division by + # cos_a accounts for extra clearance between the glyph's vertical axis + # on a sloped baseline and the edge of the bounding box. + fontsize = (line_height - abs(intercept)) / cos_a + text.setFont(fontname, fontsize) + if invisible_text: + text.setTextRenderMode(3) # Invisible (indicates OCR text) + + # Intercept is normally negative, so this places it above the bottom + # of the line box + baseline_y2 = self.height - (line_box.y2 + intercept) + + if show_bounding_boxes: # pragma: no cover + # draw the baseline in magenta, dashed + pdf.setDash() + pdf.setStrokeColor(magenta) + pdf.setLineWidth(0.5) + # negate slope because it is defined as a rise/run in pixel + # coordinates and page coordinates have the y axis flipped + pdf.line( + line_box.x1, + baseline_y2, + line_box.x2, + self.polyval((-slope, baseline_y2), line_box.x2 - line_box.x1), + ) + # light green for bounding box of word/line + pdf.setDash(6, 3) + pdf.setStrokeColor(red) + + text.setTextTransform(cos_a, -sin_a, sin_a, cos_a, line_box.x1, baseline_y2) + pdf.setFillColor(black) # text in black + + elements = line.findall(self._child_xpath('span', elemclass)) + for elem in elements: + elemtxt = self._get_element_text(elem).strip() + elemtxt = self.replace_unsupported_chars(elemtxt) + if elemtxt == '': + continue + + pxl_coords = self.element_coordinates(elem) + box = self.pt_from_pixel(pxl_coords) + if interword_spaces: + # if `--interword-spaces` is true, append a space + # to the end of each text element to allow simpler PDF viewers + # such as PDF.js to better recognize words in search and copy + # and paste. Do not remove space from last word in line, even + # though it would look better, because it will interfere with + # naive text extraction. \n does not work either. + elemtxt += ' ' + box = Rect._make( + ( + box.x1, + line_box.y1, + box.x2 + pdf.stringWidth(' ', fontname, line_height), + line_box.y2, + ) + ) + box_width = box.x2 - box.x1 + font_width = pdf.stringWidth(elemtxt, fontname, fontsize) + + # draw the bbox border + if show_bounding_boxes: # pragma: no cover + pdf.rect( + box.x1, self.height - line_box.y2, box_width, line_height, fill=0 + ) + + # Adjust relative position of cursor + # This is equivalent to: + # text.setTextOrigin(pt.x1, self.height - line_box.y2) + # but the former generates a full text reposition matrix (Tm) in the + # content stream while this issues a "offset" (Td) command. + # .moveCursor() is relative to start of the text line, where the + # "text line" means whatever reportlab defines it as. Do not use + # use .getCursor(), since moveCursor() rather unintuitively plans + # its moves relative to .getStartOfLine(). + # For skewed lines, in the text transform we set up a rotated + # coordinate system, so we don't have to account for the + # incremental offset. Surprisingly most PDF viewers can handle this. + cursor = text.getStartOfLine() + dx = box.x1 - cursor[0] + dy = baseline_y2 - cursor[1] + text.moveCursor(dx, dy) + + # If reportlab tells us this word is 0 units wide, our best seems + # to be to suppress this text + if font_width > 0: + text.setHorizScale(100 * box_width / font_width) + text.textOut(elemtxt) + pdf.drawText(text) + + +if __name__ == "__main__": + parser = argparse.ArgumentParser(description='Convert hocr file to PDF') + parser.add_argument( + '-b', + '--boundingboxes', + action="store_true", + default=False, + help='Show bounding boxes borders', + ) + parser.add_argument( + '-r', + '--resolution', + type=int, + default=300, + help='Resolution of the image that was OCRed', + ) + parser.add_argument( + '-i', + '--image', + default=None, + help='Path to the image to be placed above the text', + ) + parser.add_argument( + '--interword-spaces', + action='store_true', + default=False, + help='Add spaces between words', + ) + parser.add_argument('hocrfile', help='Path to the hocr file to be parsed') + parser.add_argument('outputfile', help='Path to the PDF file to be generated') + args = parser.parse_args() + + hocr = HocrTransform(hocr_filename=args.hocrfile, dpi=args.resolution) + hocr.to_pdf( + out_filename=args.outputfile, + image_filename=args.image, + show_bounding_boxes=args.boundingboxes, + interword_spaces=args.interword_spaces, + ) + diff --git a/scripts/hocrtransformpdf.py b/scripts/hocrtransformpdf.py new file mode 100755 index 0000000..c48c6c4 --- /dev/null +++ b/scripts/hocrtransformpdf.py @@ -0,0 +1,518 @@ +#!venv/bin python3 +# +# Copyright (c) 2010, Jonathan Brinley +# Original version from: https://github.com/jbrinley/HocrConverter +# +# Copyright (c) 2013-14, Julien Pfefferkorn +# Modifications +# +# Copyright (c) 2015-16, James R. Barlow +# Set text to transparent + +# Copyright (c) 2022, WordMord & Alex Roidl +# Set text back to visible and change bounding boxes +# +# Permission is hereby granted, free of charge, to any person obtaining a +# copy of this software and associated documentation files (the +# "Software"), to deal in the Software without restriction, including +# without limitation the rights to use, copy, modify, merge, publish, +# distribute, sublicense, and/or sell copies of the Software, and to +# permit persons to whom the Software is furnished to do so, subject to +# the following conditions: +# +# The above copyright notice and this permission notice shall be included +# in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +import argparse +import os +import re +from itertools import chain +from math import atan, cos, sin +from pathlib import Path +from typing import Any, NamedTuple, Optional, Tuple, Union +from xml.etree import ElementTree + +from reportlab.lib.colors import black, cyan, magenta, red +from reportlab.lib.units import inch +from reportlab.pdfgen.canvas import Canvas +from reportlab.pdfbase import pdfmetrics +from reportlab.pdfbase.ttfonts import TTFont +from reportlab.pdfbase.pdfmetrics import registerFontFamily + + + +# According to Wikipedia these languages are supported in the ISO-8859-1 character +# set, meaning reportlab can generate them and they are compatible with hocr, +# assuming Tesseract has the necessary languages installed. Note that there may +# not be language packs for them. +HOCR_OK_LANGS = frozenset( + [ + # Languages fully covered by Latin-1: + 'afr', # Afrikaans + 'alb', # Albanian + 'ast', # Leonese + 'baq', # Basque + 'bre', # Breton + 'cos', # Corsican + 'eng', # English + 'eus', # Basque + 'fao', # Faoese + 'gla', # Scottish Gaelic + 'glg', # Galician + 'glv', # Manx + 'ice', # Icelandic + 'ind', # Indonesian + 'isl', # Icelandic + 'ita', # Italian + 'ltz', # Luxembourgish + 'mal', # Malay Rumi + 'mga', # Irish + 'nor', # Norwegian + 'oci', # Occitan + 'por', # Portugeuse + 'roh', # Romansh + 'sco', # Scots + 'sma', # Sami + 'spa', # Spanish + 'sqi', # Albanian + 'swa', # Swahili + 'swe', # Swedish + 'tgl', # Tagalog + 'wln', # Walloon + # Languages supported by Latin-1 except for a few rare characters that OCR + # is probably not trained to recognize anyway: + 'cat', # Catalan + 'cym', # Welsh + 'dan', # Danish + 'deu', # German + 'dut', # Dutch + 'est', # Estonian + 'fin', # Finnish + 'fra', # French + 'hun', # Hungarian + 'kur', # Kurdish + 'nld', # Dutch + 'wel', # Welsh + ] +) + + +Element = ElementTree.Element + + +class Rect(NamedTuple): # pylint: disable=inherit-non-class + """A rectangle for managing PDF coordinates.""" + + x1: Any + y1: Any + x2: Any + y2: Any + + +class HocrTransformError(Exception): + pass + + +class HocrTransform: + + """ + A class for converting documents from the hOCR format. + For details of the hOCR format, see: + http://kba.cloud/hocr-spec/ + """ + + box_pattern = re.compile(r'bbox((\s+\d+){4})') + baseline_pattern = re.compile( + r''' + baseline \s+ + ([\-\+]?\d*\.?\d*) \s+ # +/- decimal float + ([\-\+]?\d+) # +/- int''', + re.VERBOSE, + ) + ligatures = str.maketrans( + {'ff': 'ff', 'ffi': 'f‌f‌i', 'ffl': 'f‌f‌l', 'fi': 'fi', 'fl': 'fl'} + ) + + def __init__(self, *, hocr_filename: Union[str, Path], dpi: float): + self.dpi = dpi + self.hocr = ElementTree.parse(os.fspath(hocr_filename)) + + # if the hOCR file has a namespace, ElementTree requires its use to + # find elements + matches = re.match(r'({.*})html', self.hocr.getroot().tag) + self.xmlns = '' + if matches: + self.xmlns = matches.group(1) + + # get dimension in pt (not pixel!!!!) of the OCRed image + self.width, self.height = None, None + for div in self.hocr.findall(self._child_xpath('div', 'ocr_page')): + coords = self.element_coordinates(div) + pt_coords = self.pt_from_pixel(coords) + self.width = pt_coords.x2 - pt_coords.x1 + self.height = pt_coords.y2 - pt_coords.y1 + # there shouldn't be more than one, and if there is, we don't want + # it + break + if self.width is None or self.height is None: + raise HocrTransformError("hocr file is missing page dimensions") + + def __str__(self): # pragma: no cover + """ + Return the textual content of the HTML body + """ + if self.hocr is None: + return '' + body = self.hocr.find(self._child_xpath('body')) + if body: + return self._get_element_text(body) + else: + return '' + + def _get_element_text(self, element: Element): + """ + Return the textual content of the element and its children + """ + text = '' + if element.text is not None: + text += element.text + for child in element: + text += self._get_element_text(child) + if element.tail is not None: + text += element.tail + return text + + @classmethod + def element_coordinates(cls, element: Element) -> Rect: + """ + Returns a tuple containing the coordinates of the bounding box around + an element + """ + out = Rect._make(0 for _ in range(4)) + if 'title' in element.attrib: + matches = cls.box_pattern.search(element.attrib['title']) + if matches: + coords = matches.group(1).split() + out = Rect._make(int(coords[n]) for n in range(4)) + return out + + @classmethod + def baseline(cls, element: Element) -> Tuple[float, float]: + """ + Returns a tuple containing the baseline slope and intercept. + """ + if 'title' in element.attrib: + matches = cls.baseline_pattern.search(element.attrib['title']) + if matches: + return float(matches.group(1)), int(matches.group(2)) + return (0.0, 0.0) + + def pt_from_pixel(self, pxl) -> Rect: + """ + Returns the quantity in PDF units (pt) given quantity in pixels + """ + return Rect._make((c / self.dpi * inch) for c in pxl) + + def _child_xpath(self, html_tag: str, html_class: Optional[str] = None) -> str: + xpath = f".//{self.xmlns}{html_tag}" + if html_class: + xpath += f"[@class='{html_class}']" + return xpath + + @classmethod + def replace_unsupported_chars(cls, s: str) -> str: + """ + Given an input string, returns the corresponding string that: + * is available in the Helvetica facetype + * does not contain any ligature (to allow easy search in the PDF file) + """ + return s.translate(cls.ligatures) + + def topdown_position(self, element): + pxl_line_coords = self.element_coordinates(element) + line_box = self.pt_from_pixel(pxl_line_coords) + # Coordinates here are still in the hocr coordinate system, so 0 on the y axis + # is the top of the page and increasing values of y will move towards the + # bottom of the page. + return line_box.y2 + + def to_pdf( + self, + *, + out_filename: Path, + image_filename: Optional[Path] = None, + show_bounding_boxes: bool = False, + fontname: str = "Helvetica", + invisible_text: bool = False, + interword_spaces: bool = False, + ) -> None: + """ + Creates a PDF file with an image superimposed on top of the text. + Text is positioned according to the bounding box of the lines in + the hOCR file. + The image need not be identical to the image used to create the hOCR + file. + It can have a lower resolution, different color mode, etc. + + Arguments: + out_filename: Path of PDF to write. + image_filename: Image to use for this file. If omitted, the OCR text + is shown. + show_bounding_boxes: Show bounding boxes around various text regions, + for debugging. + fontname: Name of font to use. + invisible_text: If True, text is rendered invisible so that is + selectable but never drawn. If False, text is visible and may + be seen if the image is skipped or deleted in Acrobat. + interword_spaces: If True, insert spaces between words rather than + drawing each word without spaces. Generally this improves text + extraction. + """ + # create the PDF file + # page size in points (1/72 in.) + + pdfmetrics.registerFont(TTFont('Greek', '../styles/fonts/greek.ttf')) + pdfmetrics.registerFont(TTFont('GreekB', '../styles/fonts/greek-bold.ttf')) + registerFontFamily('Greek', normal='Greek', bold='GreekB') + + pdf = Canvas( + os.fspath(out_filename), + pagesize=(self.width, self.height), + pageCompression=1, + ) + + if image_filename is not None: + pdf.drawImage( + os.fspath(image_filename), 0, 0, width=self.width, height=self.height + ) + + # draw bounding box for each paragraph + # light blue for bounding box of paragraph + pdf.setStrokeColor(black) + # light blue for bounding box of paragraph + pdf.setFillColor(black) + pdf.setLineWidth(1) # no line for bounding box + for elem in self.hocr.iterfind(self._child_xpath('p', 'ocr_par')): + elemtxt = self._get_element_text(elem).rstrip() + if len(elemtxt) == 0: + continue + + pxl_coords = self.element_coordinates(elem) + pt = self.pt_from_pixel(pxl_coords) + + # draw the bbox border + if show_bounding_boxes: # pragma: no cover + pdf.rect( + pt.x1, self.height - pt.y2, pt.x2 - pt.x1, pt.y2 - pt.y1, fill=1 + ) + + found_lines = False + for line in sorted( + chain( + self.hocr.iterfind(self._child_xpath('span', 'ocr_header')), + self.hocr.iterfind(self._child_xpath('span', 'ocr_line')), + self.hocr.iterfind(self._child_xpath('span', 'ocr_textfloat')), + ), + key=self.topdown_position, + ): + found_lines = True + self._do_line( + pdf, + line, + "ocrx_word", + fontname, + invisible_text, + interword_spaces, + show_bounding_boxes, + ) + + if not found_lines: + # Tesseract did not report any lines (just words) + root = self.hocr.find(self._child_xpath('div', 'ocr_page')) + self._do_line( + pdf, + root, + "ocrx_word", + fontname, + invisible_text, + interword_spaces, + show_bounding_boxes, + ) + # put the image on the page, scaled to fill the page + + + # finish up the page and save it + pdf.showPage() + pdf.save() + + @classmethod + def polyval(cls, poly, x): # pragma: no cover + return x * poly[0] + poly[1] + + def _do_line( + self, + pdf: Canvas, + line: Optional[Element], + elemclass: str, + fontname: str, + invisible_text: bool, + interword_spaces: bool, + show_bounding_boxes: bool, + ): + if not line: + return + pxl_line_coords = self.element_coordinates(line) + line_box = self.pt_from_pixel(pxl_line_coords) + line_height = line_box.y2 - line_box.y1 + + slope, pxl_intercept = self.baseline(line) + if abs(slope) < 0.005: + slope = 0.0 + angle = atan(slope) + cos_a, sin_a = cos(angle), sin(angle) + + text = pdf.beginText() + intercept = pxl_intercept / self.dpi * inch + + # Don't allow the font to break out of the bounding box. Division by + # cos_a accounts for extra clearance between the glyph's vertical axis + # on a sloped baseline and the edge of the bounding box. + fontsize = (line_height - abs(intercept)) / cos_a * 1.2 + #fontsize = 10.5 + text.setFont('Greek', fontsize) + #if invisible_text: + # text.setTextRenderMode(3) # Invisible (indicates OCR text) + + # Intercept is normally negative, so this places it above the bottom + # of the line box + baseline_y2 = self.height - (line_box.y2 + intercept) + + if False: # pragma: no cover + # draw the baseline in magenta, dashed + pdf.setDash() + pdf.setStrokeColor(magenta) + pdf.setLineWidth(0.5) + # negate slope because it is defined as a rise/run in pixel + # coordinates and page coordinates have the y axis flipped + pdf.line( + line_box.x1, + baseline_y2, + line_box.x2, + self.polyval((-slope, baseline_y2), line_box.x2 - line_box.x1), + ) + # light green for bounding box of word/line + pdf.setDash(6, 3) + pdf.setStrokeColor(red) + + #text.setTextTransform(cos_a, -sin_a, sin_a, cos_a, line_box.x1, baseline_y2) + text.setTextOrigin(line_box.x1, baseline_y2) + ##pdf.translate(line_box.x1, baseline_y2) + pdf.setFillColor(black) # text in black + + elements = line.findall(self._child_xpath('span', elemclass)) + for elem in elements: + elemtxt = self._get_element_text(elem).strip() + elemtxt = self.replace_unsupported_chars(elemtxt) + if elemtxt == '': + continue + + pxl_coords = self.element_coordinates(elem) + box = self.pt_from_pixel(pxl_coords) + if False: + # if `--interword-spaces` is true, append a space + # to the end of each text element to allow simpler PDF viewers + # such as PDF.js to better recognize words in search and copy + # and paste. Do not remove space from last word in line, even + # though it would look better, because it will interfere with + # naive text extraction. \n does not work either. + elemtxt += ' ' + box = Rect._make( + ( + box.x1, + line_box.y1, + box.x2 + pdf.stringWidth(' ', fontname, line_height), + line_box.y2, + ) + ) + box_width = box.x2 - box.x1 + font_width = pdf.stringWidth(elemtxt, fontname, fontsize) + + # draw the bbox border + if False: # pragma: no cover + pdf.rect( + box.x1, self.height - line_box.y2, box_width, line_height, fill=0 + ) + + # Adjust relative position of cursor + # This is equivalent to: + # text.setTextOrigin(pt.x1, self.height - line_box.y2) + # but the former generates a full text reposition matrix (Tm) in the + # content stream while this issues a "offset" (Td) command. + # .moveCursor() is relative to start of the text line, where the + # "text line" means whatever reportlab defines it as. Do not use + # use .getCursor(), since moveCursor() rather unintuitively plans + # its moves relative to .getStartOfLine(). + # For skewed lines, in the text transform we set up a rotated + # coordinate system, so we don't have to account for the + # incremental offset. Surprisingly most PDF viewers can handle this. + cursor = text.getStartOfLine() + dx = box.x1 - cursor[0] + dy = baseline_y2 - cursor[1] + text.moveCursor(dx, dy) + + # If reportlab tells us this word is 0 units wide, our best seems + # to be to suppress this text + if font_width > 0: + #text.setHorizScale(100 * box_width / font_width) + text.textOut(elemtxt) + pdf.drawText(text) + + +if __name__ == "__main__": + parser = argparse.ArgumentParser(description='Convert hocr file to PDF') + parser.add_argument( + '-b', + '--boundingboxes', + action="store_true", + default=False, + help='Show bounding boxes borders', + ) + parser.add_argument( + '-r', + '--resolution', + type=int, + default=300, + help='Resolution of the image that was OCRed', + ) + parser.add_argument( + '-i', + '--image', + default=None, + help='Path to the image to be placed above the text', + ) + parser.add_argument( + '--interword-spaces', + action='store_true', + default=False, + help='Add spaces between words', + ) + parser.add_argument('hocrfile', help='Path to the hocr file to be parsed') + parser.add_argument('outputfile', help='Path to the PDF file to be generated') + args = parser.parse_args() + + hocr = HocrTransform(hocr_filename=args.hocrfile, dpi=args.resolution) + hocr.to_pdf( + out_filename=args.outputfile, + image_filename=args.image, + show_bounding_boxes=args.boundingboxes, + interword_spaces=args.interword_spaces, + ) + diff --git a/scripts/templates/base.html b/scripts/templates/base.html new file mode 100644 index 0000000..251235b --- /dev/null +++ b/scripts/templates/base.html @@ -0,0 +1,23 @@ + + + + + + + + + {% block title %} {% endblock %} WordMord + + + +
+ {% block content %} {% endblock %} +
+ + \ No newline at end of file diff --git a/scripts/templates/results.html b/scripts/templates/results.html new file mode 100644 index 0000000..6e8f945 --- /dev/null +++ b/scripts/templates/results.html @@ -0,0 +1,121 @@ +{% extends 'base.html' %} + +{% block content %} + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ perioxi epikollimenou keimenou / pasted text area +
+
+ + + + +
+ epishmeiomenos poinikos kodikas / annotated penal code + +
+ metalucktriomeno PDF / distorted PDF +
+
+
+ +
+ 		+ +
+ + + + + + +{% endblock %}