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
  20 from mediagoblin import mg_globals as mgg
  21 from mediagoblin.processing import BadMediaFail, \
  22     create_pub_filepath, THUMB_SIZE, MEDIUM_SIZE
  23 from mediagoblin.tools.exif import exif_fix_image_orientation, \
  24     extract_exif, clean_exif, get_gps_data, get_useful
  25
  26 def process_image(entry):
  27     """
  28     Code to process an image
  29     """
  30     workbench = mgg.workbench_manager.create_workbench()
  31     # Conversions subdirectory to avoid collisions
  32     conversions_subdir = os.path.join(
  33         workbench.dir, 'conversions')
  34     os.mkdir(conversions_subdir)
  35
  36     queued_filepath = entry.queued_media_file
  37     queued_filename = workbench.localized_file(
  38         mgg.queue_store, queued_filepath,
  39         'source')
  40
  41     filename_bits = os.path.splitext(queued_filename)
  42     basename = os.path.split(filename_bits[0])[1]
  43     extension = filename_bits[1].lower()
  44
  45     # EXIF extraction
  46     exif_tags = extract_exif(queued_filename)
  47     gps_data = get_gps_data(exif_tags)
  48
  49     try:
  50         thumb = Image.open(queued_filename)
  51     except IOError:
  52         raise BadMediaFail()
  53
  54     thumb = exif_fix_image_orientation(thumb, exif_tags)
  55
  56     thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
  57
  58     # Copy the thumb to the conversion subdir, then remotely.
  59     thumb_filename = 'thumbnail' + extension
  60     thumb_filepath = create_pub_filepath(entry, thumb_filename)
  61
  62     tmp_thumb_filename = os.path.join(
  63         conversions_subdir, thumb_filename)
  64
  65     with file(tmp_thumb_filename, 'w') as thumb_file:
  66         thumb.save(thumb_file)
  67
  68     mgg.public_store.copy_local_to_storage(
  69         tmp_thumb_filename, thumb_filepath)
  70
  71     # If the size of the original file exceeds the specified size of a `medium`
  72     # file, a `medium.jpg` files is created and later associated with the media
  73     # entry.
  74     medium = Image.open(queued_filename)
  75
  76     # Fix orientation
  77     medium = exif_fix_image_orientation(medium, exif_tags)
  78
  79     if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
  80         medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
  81
  82     medium_filename = 'medium' + extension
  83     medium_filepath = create_pub_filepath(entry, medium_filename)
  84
  85     tmp_medium_filename = os.path.join(
  86         conversions_subdir, medium_filename)
  87
  88     with file(tmp_medium_filename, 'w') as medium_file:
  89         medium.save(medium_file)
  90
  91     mgg.public_store.copy_local_to_storage(
  92         tmp_medium_filename, medium_filepath)
  93
  94     # we have to re-read because unlike PIL, not everything reads
  95     # things in string representation :)
  96     queued_file = file(queued_filename, 'rb')
  97
  98     with queued_file:
  99         #create_pub_filepath(entry, queued_filepath[-1])
 100         original_filepath = create_pub_filepath(entry, basename + extension)
 101
 102         with mgg.public_store.get_file(original_filepath, 'wb') \
 103             as original_file:
 104             original_file.write(queued_file.read())
 105
 106     # Remove queued media file from storage and database
 107     mgg.queue_store.delete_file(queued_filepath)
 108     entry.queued_media_file = []
 109
 110     # Insert media file information into database
 111     media_files_dict = entry.setdefault('media_files', {})
 112     media_files_dict['thumb'] = thumb_filepath
 113     media_files_dict['original'] = original_filepath
 114     media_files_dict['medium'] = medium_filepath
 115
 116     # Insert exif data into database
 117     exif_all = clean_exif(exif_tags)
 118
 119     if len(exif_all):
 120         entry.media_data_init(exif_all=exif_all)
 121
 122     if len(gps_data):
 123         for key in list(gps_data.keys()):
 124             gps_data['gps_' + key] = gps_data.pop(key)
 125         entry.media_data_init(**gps_data)
 126
 127     # clean up workbench
 128     workbench.destroy_self()
 129
 130 if __name__ == '__main__':
 131     import sys
 132     import pprint
 133
 134     pp = pprint.PrettyPrinter()
 135
 136     result = extract_exif(sys.argv[1])
 137     gps = get_gps_data(result)
 138     clean = clean_exif(result)
 139     useful = get_useful(clean)
 140
 141     print pp.pprint(
 142         clean)