66 lines
2.0 KiB
Python
66 lines
2.0 KiB
Python
#Some code from http://wiki.github.com/hoffstaetter/python-tesseract
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import codecs
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import os
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import subprocess
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import tempfile
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from django.utils.translation import ugettext as _
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from django.contrib import messages
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from common import TEMPORARY_DIRECTORY
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from documents.models import Document
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from converter.api import convert_document_for_ocr
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from ocr.conf.settings import TESSERACT_PATH
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from ocr.conf.settings import TESSERACT_LANGUAGE
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class TesseractError(Exception):
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pass
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def cleanup(filename):
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''' tries to remove the given filename. Ignores non-existent files '''
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try:
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os.remove(filename)
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except OSError:
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pass
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def run_tesseract(input_filename, output_filename_base, lang=None):
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command = [TESSERACT_PATH, input_filename, output_filename_base]
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if lang is not None:
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command += ['-l', lang]
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proc = subprocess.Popen(command, close_fds=True, stderr=subprocess.PIPE, stdout=subprocess.PIPE)
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return_code = proc.wait()
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if return_code != 0:
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error_text = proc.stderr.read()
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raise TesseractError(error_text)
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def do_document_ocr(document):
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for page_index, document_page in enumerate(document.documentpage_set.all()):
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imagefile = convert_document_for_ocr(document, page=page_index)
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desc, filepath = tempfile.mkstemp()
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try:
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run_tesseract(imagefile, filepath, TESSERACT_LANGUAGE)
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ocr_output = os.extsep.join([filepath, 'txt'])
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f = codecs.open(ocr_output, 'r', 'utf-8')
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document_page = document.documentpage_set.get(page_number=page_index+1)
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document_page.content = f.read().strip()
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document_page.page_label = _(u'Text from OCR')
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document_page.save()
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f.close()
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cleanup(ocr_output)
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except TesseractError, e:
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cleanup(filepath)
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cleanup(imagefile)
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raise TesseractError(e)
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finally:
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cleanup(filepath)
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cleanup(imagefile)
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