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     exif_image_needs_rotation
  26
  27 def process_image(entry):
  28     """
  29     Code to process an image
  30     """
  31     workbench = mgg.workbench_manager.create_workbench()
  32     # Conversions subdirectory to avoid collisions
  33     conversions_subdir = os.path.join(
  34         workbench.dir, 'conversions')
  35     os.mkdir(conversions_subdir)
  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     if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1] \
  76         or exif_image_needs_rotation(exif_tags):
  77
  78         medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
  79
  80
  81
  82         # Fix orientation
  83         medium = exif_fix_image_orientation(medium, exif_tags)
  84
  85
  86
  87         medium_filename = 'medium' + extension
  88         medium_filepath = create_pub_filepath(entry, medium_filename)
  89
  90         tmp_medium_filename = os.path.join(
  91             conversions_subdir, medium_filename)
  92
  93         with file(tmp_medium_filename, 'w') as medium_file:
  94             medium.save(medium_file)
  95
  96         mgg.public_store.copy_local_to_storage(
  97             tmp_medium_filename, medium_filepath)
  98     else:
  99         medium_filepath = None
 100
 101     # we have to re-read because unlike PIL, not everything reads
 102     # things in string representation :)
 103     queued_file = file(queued_filename, 'rb')
 104
 105     with queued_file:
 106         #create_pub_filepath(entry, queued_filepath[-1])
 107         original_filepath = create_pub_filepath(entry, basename + extension)
 108
 109         with mgg.public_store.get_file(original_filepath, 'wb') \
 110             as original_file:
 111             original_file.write(queued_file.read())
 112
 113     # Remove queued media file from storage and database
 114     mgg.queue_store.delete_file(queued_filepath)
 115     entry.queued_media_file = []
 116
 117     # Insert media file information into database
 118     media_files_dict = entry.setdefault('media_files', {})
 119     media_files_dict['thumb'] = thumb_filepath
 120     media_files_dict['original'] = original_filepath
 121     if medium_filepath:
 122         media_files_dict['medium'] = medium_filepath
 123
 124     # Insert exif data into database
 125     media_data = entry.setdefault('media_data', {})
 126     media_data['exif'] = {
 127         'clean': clean_exif(exif_tags)}
 128     media_data['exif']['useful'] = get_useful(
 129         media_data['exif']['clean'])
 130     media_data['gps'] = gps_data
 131
 132     # clean up workbench
 133     workbench.destroy_self()
 134
 135 if __name__ == '__main__':
 136     import sys
 137     import pprint
 138
 139     pp = pprint.PrettyPrinter()
 140
 141     result = extract_exif(sys.argv[1])
 142     gps = get_gps_data(result)
 143     clean = clean_exif(result)
 144     useful = get_useful(clean)
 145
 146     print pp.pprint(
 147         clean)