mediagoblin/media_types/image/processing.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import Image
  18 import os
  19 import logging
  20
  21 from mediagoblin import mg_globals as mgg
  22 from mediagoblin.processing import BadMediaFail, \
  23     create_pub_filepath, THUMB_SIZE, MEDIUM_SIZE
  24 from mediagoblin.tools.exif import exif_fix_image_orientation, \
  25     extract_exif, clean_exif, get_gps_data, get_useful
  26
  27 _log = logging.getLogger(__name__)
  28
  29 SUPPORTED_FILETYPES = ['png', 'gif', 'jpg', 'jpeg']
  30
  31 def sniff_handler(media_file, **kw):
  32     if not kw.get('media') == None:  # That's a double negative!
  33         name, ext = os.path.splitext(kw['media'].filename)
  34         clean_ext = ext[1:].lower()  # Strip the . from ext and make lowercase
  35
  36         _log.debug('name: {0}\next: {1}\nlower_ext: {2}'.format(
  37                 name,
  38                 ext,
  39                 clean_ext))
  40
  41         if clean_ext in SUPPORTED_FILETYPES:
  42             _log.info('Found file extension in supported filetypes')
  43             return True
  44         else:
  45             _log.debug('Media present, extension not found in {1}'.format(
  46                     SUPPORTED_FILETYPES))
  47     else:
  48         _log.warning('Need additional information (keyword argument \'media\')'
  49                      ' to be able to handle sniffing')
  50
  51     return False
  52
  53 def process_image(entry):
  54     """
  55     Code to process an image
  56     """
  57     workbench = mgg.workbench_manager.create_workbench()
  58     # Conversions subdirectory to avoid collisions
  59     conversions_subdir = os.path.join(
  60         workbench.dir, 'conversions')
  61     os.mkdir(conversions_subdir)
  62
  63     queued_filepath = entry.queued_media_file
  64     queued_filename = workbench.localized_file(
  65         mgg.queue_store, queued_filepath,
  66         'source')
  67
  68     filename_bits = os.path.splitext(queued_filename)
  69     basename = os.path.split(filename_bits[0])[1]
  70     extension = filename_bits[1].lower()
  71
  72     # EXIF extraction
  73     exif_tags = extract_exif(queued_filename)
  74     gps_data = get_gps_data(exif_tags)
  75
  76     try:
  77         thumb = Image.open(queued_filename)
  78     except IOError:
  79         raise BadMediaFail()
  80
  81     thumb = exif_fix_image_orientation(thumb, exif_tags)
  82
  83     thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
  84
  85     # Copy the thumb to the conversion subdir, then remotely.
  86     thumb_filename = 'thumbnail' + extension
  87     thumb_filepath = create_pub_filepath(entry, thumb_filename)
  88
  89     tmp_thumb_filename = os.path.join(
  90         conversions_subdir, thumb_filename)
  91
  92     with file(tmp_thumb_filename, 'w') as thumb_file:
  93         thumb.save(thumb_file)
  94
  95     mgg.public_store.copy_local_to_storage(
  96         tmp_thumb_filename, thumb_filepath)
  97
  98     # If the size of the original file exceeds the specified size of a `medium`
  99     # file, a `medium.jpg` files is created and later associated with the media
 100     # entry.
 101     medium = Image.open(queued_filename)
 102
 103     # Fix orientation
 104     medium = exif_fix_image_orientation(medium, exif_tags)
 105
 106     if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
 107         medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
 108
 109     medium_filename = 'medium' + extension
 110     medium_filepath = create_pub_filepath(entry, medium_filename)
 111
 112     tmp_medium_filename = os.path.join(
 113         conversions_subdir, medium_filename)
 114
 115     with file(tmp_medium_filename, 'w') as medium_file:
 116         medium.save(medium_file)
 117
 118     mgg.public_store.copy_local_to_storage(
 119         tmp_medium_filename, medium_filepath)
 120
 121     # we have to re-read because unlike PIL, not everything reads
 122     # things in string representation :)
 123     queued_file = file(queued_filename, 'rb')
 124
 125     with queued_file:
 126         #create_pub_filepath(entry, queued_filepath[-1])
 127         original_filepath = create_pub_filepath(entry, basename + extension)
 128
 129         with mgg.public_store.get_file(original_filepath, 'wb') \
 130             as original_file:
 131             original_file.write(queued_file.read())
 132
 133     # Remove queued media file from storage and database
 134     mgg.queue_store.delete_file(queued_filepath)
 135     entry.queued_media_file = []
 136
 137     # Insert media file information into database
 138     media_files_dict = entry.setdefault('media_files', {})
 139     media_files_dict['thumb'] = thumb_filepath
 140     media_files_dict['original'] = original_filepath
 141     media_files_dict['medium'] = medium_filepath
 142
 143     # Insert exif data into database
 144     media_data = entry.setdefault('media_data', {})
 145     media_data['exif'] = {
 146         'clean': clean_exif(exif_tags)}
 147     media_data['exif']['useful'] = get_useful(
 148         media_data['exif']['clean'])
 149     media_data['gps'] = gps_data
 150
 151     # clean up workbench
 152     workbench.destroy_self()
 153
 154 if __name__ == '__main__':
 155     import sys
 156     import pprint
 157
 158     pp = pprint.PrettyPrinter()
 159
 160     result = extract_exif(sys.argv[1])
 161     gps = get_gps_data(result)
 162     clean = clean_exif(result)
 163     useful = get_useful(clean)
 164
 165     print pp.pprint(
 166         clean)