#! /usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2013, Marten de Vries
#
# This file is part of OpenTeacher.
#
# OpenTeacher is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OpenTeacher is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with OpenTeacher. If not, see <http://www.gnu.org/licenses/>.
import os
import tempfile
import subprocess
import distutils.spawn
class TesseractOCRModule:
"""Recognizes text in an image with the Tesseract OCR program.
Outputs to HOCR.
"""
def __init__(self, moduleManager, *args, **kwargs):
super().__init__(*args, **kwargs)
self._mm = moduleManager
self.type = "ocrRecognizer"
self.priorities = {
"default": 333,
}
def toHocr(self, path):
fd, hocrPath = tempfile.mkstemp(".html")
os.close(fd)
self._callTesseract(path, os.path.splitext(hocrPath)[0], "hocr")
with open(hocrPath, 'r', encoding="UTF-8") as f:
hocr = f.read()
os.remove(hocrPath)
return hocr
def _callTesseract(self, *args):
with open(os.devnull, "wb") as f:
return subprocess.call(["tesseract"] + list(args), stdout=f, stderr=subprocess.STDOUT)
def enable(self):
if not distutils.spawn.find_executable("tesseract"):# pragma: no cover
#remain inactive
return
self.active = True
def disable(self):
self.active = False
def init(moduleManager):
return TesseractOCRModule(moduleManager)