Files
mayan-edms/apps/converter/api.py

227 lines
7.5 KiB
Python

import os
import subprocess
from django.utils.importlib import import_module
from django.template.defaultfilters import slugify
from converter.conf.settings import UNPAPER_PATH
from converter.conf.settings import OCR_OPTIONS
from converter.conf.settings import DEFAULT_OPTIONS
from converter.conf.settings import LOW_QUALITY_OPTIONS
from converter.conf.settings import HIGH_QUALITY_OPTIONS
from converter.conf.settings import PRINT_QUALITY_OPTIONS
from converter.conf.settings import GRAPHICS_BACKEND
from converter.conf.settings import UNOCONV_PATH
from converter.exceptions import UnpaperError, OfficeConversionError
from common import TEMPORARY_DIRECTORY
from documents.utils import document_save_to_temp_dir
DEFAULT_ZOOM_LEVEL = 100
DEFAULT_ROTATION = 0
DEFAULT_PAGE_INDEX_NUMBER = 0
DEFAULT_FILE_FORMAT = u'jpg'
DEFAULT_OCR_FILE_FORMAT = u'tif'
QUALITY_DEFAULT = u'quality_default'
QUALITY_LOW = u'quality_low'
QUALITY_HIGH = u'quality_high'
QUALITY_PRINT = u'quality_print'
QUALITY_SETTINGS = {
QUALITY_DEFAULT: DEFAULT_OPTIONS,
QUALITY_LOW: LOW_QUALITY_OPTIONS,
QUALITY_HIGH: HIGH_QUALITY_OPTIONS,
QUALITY_PRINT: PRINT_QUALITY_OPTIONS
}
CONVERTER_OFFICE_FILE_EXTENSIONS = [
u'ods', u'docx', u'doc'
]
def _lazy_load(fn):
_cached = []
def _decorated():
if not _cached:
_cached.append(fn())
return _cached[0]
return _decorated
@_lazy_load
def _get_backend():
return import_module(GRAPHICS_BACKEND)
try:
backend = _get_backend()
except ImportError:
raise ImportError(u'Missing or incorrect converter backend: %s' % GRAPHICS_BACKEND)
def cleanup(filename):
''' tries to remove the given filename. Ignores non-existent files '''
try:
os.remove(filename)
except OSError:
pass
def execute_unpaper(input_filepath, output_filepath):
command = []
command.append(UNPAPER_PATH)
command.append(u'--overwrite')
command.append(input_filepath)
command.append(output_filepath)
proc = subprocess.Popen(command, close_fds=True, stderr=subprocess.PIPE)
return_code = proc.wait()
if return_code != 0:
raise UnpaperError(proc.stderr.readline())
def execute_unoconv(input_filepath, arguments=''):
command = []
command.append(UNOCONV_PATH)
command.extend(unicode(arguments).split())
command.append(input_filepath)
proc = subprocess.Popen(command, close_fds=True, stderr=subprocess.PIPE)
return_code = proc.wait()
if return_code != 0:
raise OfficeConversionError(proc.stderr.readline())
def cache_cleanup(input_filepath, *args, **kwargs):
try:
os.remove(create_image_cache_filename(input_filepath, *args, **kwargs))
except OSError:
pass
def create_image_cache_filename(input_filepath, *args, **kwargs):
if input_filepath:
temp_filename, separator = os.path.splitext(os.path.basename(input_filepath))
temp_path = os.path.join(TEMPORARY_DIRECTORY, temp_filename)
final_filepath = []
[final_filepath.append(str(arg)) for arg in args]
final_filepath.extend([u'%s_%s' % (key, value) for key, value in kwargs.items()])
temp_path += slugify(u'_'.join(final_filepath))
return temp_path
else:
return None
def convert_office_document(input_filepath):
if os.path.exists(UNOCONV_PATH):
execute_unoconv(input_filepath, arguments='-f pdf')
return input_filepath + u'.pdf'
return None
def convert_document(document, *args, **kwargs):
document_filepath = create_image_cache_filename(document.checksum, *args, **kwargs)
if os.path.exists(document_filepath):
return document_filepath
return convert(document_save_to_temp_dir(document, document.checksum), *args, **kwargs)
def convert(input_filepath, *args, **kwargs):
size = kwargs.get('size')
file_format = kwargs.get('file_format', DEFAULT_FILE_FORMAT)
extra_options = kwargs.get('extra_options', u'')
zoom = kwargs.get('zoom', DEFAULT_ZOOM_LEVEL)
rotation = kwargs.get('rotation', DEFAULT_ROTATION)
page = kwargs.get('page', DEFAULT_PAGE_INDEX_NUMBER)
cleanup_files = kwargs.get('cleanup_files', True)
quality = kwargs.get('quality', QUALITY_DEFAULT)
unoconv_output = None
output_filepath = create_image_cache_filename(input_filepath, *args, **kwargs)
if os.path.exists(output_filepath):
return output_filepath
path, extension = os.path.splitext(input_filepath)
if extension[1:].lower() in CONVERTER_OFFICE_FILE_EXTENSIONS:
result = convert_office_document(input_filepath)
if result:
unoconv_output = result
input_filepath = result
extra_options = u''
input_arg = u'%s[%s]' % (input_filepath, page)
extra_options += u' -resize %s' % size
if zoom != 100:
extra_options += u' -resize %d%% ' % zoom
if rotation != 0 and rotation != 360:
extra_options += u' -rotate %d ' % rotation
if format == u'jpg':
extra_options += u' -quality 85'
try:
backend.execute_convert(input_filepath=input_arg, arguments=extra_options, output_filepath=u'%s:%s' % (file_format, output_filepath), quality=quality)
finally:
if cleanup_files:
cleanup(input_filepath)
if unoconv_output:
cleanup(unoconv_output)
return output_filepath
def get_page_count(input_filepath):
try:
return len(backend.execute_identify(unicode(input_filepath)).splitlines())
except:
#TODO: send to other page number identifying program
return 1
def get_document_dimensions(document, *args, **kwargs):
document_filepath = create_image_cache_filename(document.checksum, *args, **kwargs)
if os.path.exists(document_filepath):
options = [u'-format', u'%w %h']
return [int(dimension) for dimension in backend.execute_identify(unicode(document_filepath), options).split()]
else:
return [0, 0]
def convert_document_for_ocr(document, page=DEFAULT_PAGE_INDEX_NUMBER, file_format=DEFAULT_OCR_FILE_FORMAT):
#Extract document file
input_filepath = document_save_to_temp_dir(document, document.uuid)
#Convert for OCR
temp_filename, separator = os.path.splitext(os.path.basename(input_filepath))
temp_path = os.path.join(TEMPORARY_DIRECTORY, temp_filename)
transformation_output_file = u'%s_trans%s%s%s' % (temp_path, page, os.extsep, file_format)
unpaper_input_file = u'%s_unpaper_in%s%spnm' % (temp_path, page, os.extsep)
unpaper_output_file = u'%s_unpaper_out%s%spnm' % (temp_path, page, os.extsep)
convert_output_file = u'%s_ocr%s%s%s' % (temp_path, page, os.extsep, file_format)
input_arg = u'%s[%s]' % (input_filepath, page)
try:
document_page = document.documentpage_set.get(page_number=page + 1)
transformation_string, warnings = document_page.get_transformation_string()
#Apply default transformations
backend.execute_convert(input_filepath=input_arg, quality=QUALITY_HIGH, arguments=transformation_string, output_filepath=transformation_output_file)
#Do OCR operations
backend.execute_convert(input_filepath=transformation_output_file, arguments=OCR_OPTIONS, output_filepath=unpaper_input_file)
# Process by unpaper
execute_unpaper(input_filepath=unpaper_input_file, output_filepath=unpaper_output_file)
# Convert to tif
backend.execute_convert(input_filepath=unpaper_output_file, output_filepath=convert_output_file)
finally:
cleanup(transformation_output_file)
cleanup(unpaper_input_file)
cleanup(unpaper_output_file)
return convert_output_file