def extract_pdf(path, languages=None):
"""
Extract content from a PDF file.
This will attempt to use pdfminer to extract textual content from
each page. If none is found, it'll send the images through OCR.
"""
with open(path, 'rb') as fh:
rsrcmgr = PDFResourceManager()
laparams = LAParams()
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
interpreter = PDFPageInterpreter(rsrcmgr, device)
parser = PDFParser(fh)
doc = PDFDocument(parser, '')
result = {'pages': []}
if len(doc.info):
for k, v in doc.info[-1].items():
k = k.lower().strip()
v = string_value(v)
if k != 'pages' and v is not None and '<PDFObjRef:' not in v:
result[k] = string_value(v)
for i, page in enumerate(PDFPage.create_pages(doc)):
text = None
try:
interpreter.process_page(page)
layout = device.get_result()
text = _convert_page(layout, path)
except Exception as ex:
log.warning("Failed to parse PDF page: %r", ex)
if text is None or len(text) < 3:
log.info("OCR: %r, pg. %s", path, i + 1)
text = _extract_image_page(path, i + 1, languages)
result['pages'].append(text)
device.close()
return result
def extract_pdf(path, languages=None):
"""
Extract content from a PDF file.
This will attempt to use pdfminer to extract textual content from
each page. If none is found, it'll send the images through OCR.
"""
with open(path, 'rb') as fh:
rsrcmgr = PDFResourceManager()
laparams = LAParams()
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
interpreter = PDFPageInterpreter(rsrcmgr, device)
parser = PDFParser(fh)
doc = PDFDocument(parser, '')
result = {'pages': []}
if len(doc.info):
for k, v in doc.info[-1].items():
k = k.lower().strip()
v = string_value(v)
if k != 'pages' and v is not None and '<PDFObjRef:' not in v:
result[k] = string_value(v)
for i, page in enumerate(PDFPage.create_pages(doc)):
text = None
try:
interpreter.process_page(page)
layout = device.get_result()
text = _convert_page(layout, path)
except Exception as ex:
log.warning("Failed to parse PDF page: %r", ex)
if text is None or len(text) < 3:
log.info("OCR: %r, pg. %s", path, i + 1)
text = _extract_image_page(path, i + 1, languages)
result['pages'].append(text)
device.close()
return result
def _convert_page(interpreter, page, device, page_no, path, languages):
# If this returns None or an empty string, it'll trigger OCR.
text_content = []
ocr_required = False
try:
interpreter.process_page(page)
layout = device.get_result()
for text_obj in _find_objects(layout._objs, (LTTextBox, LTTextLine)):
text = text_obj.get_text()
if text is None:
continue
text = text.strip()
if len(text):
text_content.append(text)
# Generous try/catch because pdfminers image support is
# horrible.
page_area = float(layout.width * layout.height)
for image_obj in _find_objects(layout._objs, LTImage):
image_area = float(image_obj.width * image_obj.height)
page_portion = image_area / page_area
# Go for OCR if an image makes up more than 70% of the page.
if page_portion > 0.7:
ocr_required = True
except Exception as ex:
log.exception(ex)
ocr_required = True
if ocr_required and get_config("OCR_PDF_PAGES"):
log.info("Using OCR for %r, p.%s", path, page_no)
text_content.append(_extract_image_page(path, page_no, languages))
text = "\n".join(text_content)
log.debug("Extracted %d characters of text from %r, p.%s", len(text), path, page_no)
return text.strip()
