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
  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
  32 def sniff_handler(media_file, **kw):
  33     if kw.get('media') is not None:  # That's a double negative!
  34         name, ext = os.path.splitext(kw['media'].filename)
  35         clean_ext = ext[1:].lower()  # Strip the . from ext and make lowercase
  36
  37         _log.debug('name: {0}\next: {1}\nlower_ext: {2}'.format(
  38                 name,
  39                 ext,
  40                 clean_ext))
  41
  42         if clean_ext in SUPPORTED_FILETYPES:
  43             _log.info('Found file extension in supported filetypes')
  44             return True
  45         else:
  46             _log.debug('Media present, extension not found in {0}'.format(
  47                     SUPPORTED_FILETYPES))
  48     else:
  49         _log.warning('Need additional information (keyword argument \'media\')'
  50                      ' to be able to handle sniffing')
  51
  52     return False
  53
  54
  55 def process_image(entry):
  56     """
  57     Code to process an image
  58     """
  59     workbench = mgg.workbench_manager.create_workbench()
  60     # Conversions subdirectory to avoid collisions
  61     conversions_subdir = os.path.join(
  62         workbench.dir, 'conversions')
  63     os.mkdir(conversions_subdir)
  64
  65     queued_filepath = entry.queued_media_file
  66     queued_filename = workbench.localized_file(
  67         mgg.queue_store, queued_filepath,
  68         'source')
  69
  70     filename_bits = os.path.splitext(queued_filename)
  71     basename = os.path.split(filename_bits[0])[1]
  72     extension = filename_bits[1].lower()
  73
  74     # EXIF extraction
  75     exif_tags = extract_exif(queued_filename)
  76     gps_data = get_gps_data(exif_tags)
  77
  78     try:
  79         thumb = Image.open(queued_filename)
  80     except IOError:
  81         raise BadMediaFail()
  82
  83     thumb = exif_fix_image_orientation(thumb, exif_tags)
  84
  85     thumb.thumbnail(
  86         (mgg.global_config['media:thumb']['max_width'],
  87          mgg.global_config['media:thumb']['max_height']),
  88         Image.ANTIALIAS)
  89
  90     # Copy the thumb to the conversion subdir, then remotely.
  91     thumb_filename = 'thumbnail' + extension
  92     thumb_filepath = create_pub_filepath(entry, thumb_filename)
  93
  94     tmp_thumb_filename = os.path.join(
  95         conversions_subdir, thumb_filename)
  96
  97     with file(tmp_thumb_filename, 'w') as thumb_file:
  98         thumb.save(thumb_file)
  99
 100     mgg.public_store.copy_local_to_storage(
 101         tmp_thumb_filename, thumb_filepath)
 102
 103     # If the size of the original file exceeds the specified size of a `medium`
 104     # file, a `medium.jpg` files is created and later associated with the media
 105     # entry.
 106     medium = Image.open(queued_filename)
 107
 108     # Fix orientation
 109     medium = exif_fix_image_orientation(medium, exif_tags)
 110
 111     if medium.size[0] > mgg.global_config['media:medium']['max_width'] \
 112         or medium.size[1] > mgg.global_config['media:medium']['max_height']:
 113         medium.thumbnail(
 114             (mgg.global_config['media:medium']['max_width'],
 115              mgg.global_config['media:medium']['max_height']),
 116             Image.ANTIALIAS)
 117
 118     medium_filename = 'medium' + extension
 119     medium_filepath = create_pub_filepath(entry, medium_filename)
 120
 121     tmp_medium_filename = os.path.join(
 122         conversions_subdir, medium_filename)
 123
 124     with file(tmp_medium_filename, 'w') as medium_file:
 125         medium.save(medium_file)
 126
 127     mgg.public_store.copy_local_to_storage(
 128         tmp_medium_filename, medium_filepath)
 129
 130     # we have to re-read because unlike PIL, not everything reads
 131     # things in string representation :)
 132     queued_file = file(queued_filename, 'rb')
 133
 134     with queued_file:
 135         #create_pub_filepath(entry, queued_filepath[-1])
 136         original_filepath = create_pub_filepath(entry, basename + extension)
 137
 138         with mgg.public_store.get_file(original_filepath, 'wb') \
 139             as original_file:
 140             original_file.write(queued_file.read())
 141
 142     # Remove queued media file from storage and database
 143     mgg.queue_store.delete_file(queued_filepath)
 144     entry.queued_media_file = []
 145
 146     # Insert media file information into database
 147     media_files_dict = entry.setdefault('media_files', {})
 148     media_files_dict['thumb'] = thumb_filepath
 149     media_files_dict['original'] = original_filepath
 150     media_files_dict['medium'] = medium_filepath
 151
 152     # Insert exif data into database
 153     media_data = entry.setdefault('media_data', {})
 154     media_data['exif'] = {
 155         'clean': clean_exif(exif_tags)}
 156     media_data['exif']['useful'] = get_useful(
 157         media_data['exif']['clean'])
 158     media_data['gps'] = gps_data
 159
 160     # clean up workbench
 161     workbench.destroy_self()
 162
 163 if __name__ == '__main__':
 164     import sys
 165     import pprint
 166
 167     pp = pprint.PrettyPrinter()
 168
 169     result = extract_exif(sys.argv[1])
 170     gps = get_gps_data(result)
 171     clean = clean_exif(result)
 172     useful = get_useful(clean)
 173
 174     print pp.pprint(
 175         clean)