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 try:
  18     from PIL import Image
  19 except ImportError:
  20     import Image
  21 import os
  22 import logging
  23 import argparse
  24
  25 from mediagoblin import mg_globals as mgg
  26 from mediagoblin.processing import (
  27     BadMediaFail, FilenameBuilder,
  28     MediaProcessor, ProcessingManager,
  29     request_from_args, get_process_filename,
  30     store_public, copy_original)
  31 from mediagoblin.tools.exif import exif_fix_image_orientation, \
  32     extract_exif, clean_exif, get_gps_data, get_useful, \
  33     exif_image_needs_rotation
  34
  35 _log = logging.getLogger(__name__)
  36
  37 PIL_FILTERS = {
  38     'NEAREST': Image.NEAREST,
  39     'BILINEAR': Image.BILINEAR,
  40     'BICUBIC': Image.BICUBIC,
  41     'ANTIALIAS': Image.ANTIALIAS}
  42
  43 MEDIA_TYPE = 'mediagoblin.media_types.image'
  44
  45
  46 def resize_image(entry, resized, keyname, target_name, new_size,
  47                  exif_tags, workdir, quality, filter):
  48     """
  49     Store a resized version of an image and return its pathname.
  50
  51     Arguments:
  52     proc_state -- the processing state for the image to resize
  53     resized -- an image from Image.open() of the original image being resized
  54     keyname -- Under what key to save in the db.
  55     target_name -- public file path for the new resized image
  56     exif_tags -- EXIF data for the original image
  57     workdir -- directory path for storing converted image files
  58     new_size -- 2-tuple size for the resized image
  59     quality -- level of compression used when resizing images
  60     filter -- One of BICUBIC, BILINEAR, NEAREST, ANTIALIAS
  61     """
  62     resized = exif_fix_image_orientation(resized, exif_tags)  # Fix orientation
  63
  64     try:
  65         resize_filter = PIL_FILTERS[filter.upper()]
  66     except KeyError:
  67         raise Exception('Filter "{0}" not found, choose one of {1}'.format(
  68             unicode(filter),
  69             u', '.join(PIL_FILTERS.keys())))
  70
  71     resized.thumbnail(new_size, resize_filter)
  72
  73     # Copy the new file to the conversion subdir, then remotely.
  74     tmp_resized_filename = os.path.join(workdir, target_name)
  75     with file(tmp_resized_filename, 'w') as resized_file:
  76         resized.save(resized_file, quality=quality)
  77     store_public(entry, keyname, tmp_resized_filename, target_name)
  78
  79     # store the thumb/medium info
  80     image_info = {'width': new_size[0],
  81                   'height': new_size[1],
  82                   'quality': quality,
  83                   'filter': filter}
  84
  85     entry.set_file_metadata(keyname, **image_info)
  86
  87
  88 def resize_tool(entry,
  89                 force, keyname, orig_file, target_name,
  90                 conversions_subdir, exif_tags, quality, filter, new_size=None):
  91     # Use the default size if new_size was not given
  92     if not new_size:
  93         max_width = mgg.global_config['media:' + keyname]['max_width']
  94         max_height = mgg.global_config['media:' + keyname]['max_height']
  95         new_size = (max_width, max_height)
  96
  97     # If thumb or medium is already the same quality and size, then don't
  98     # reprocess
  99     if _skip_resizing(entry, keyname, new_size, quality, filter):
 100         _log.info('{0} of same size and quality already in use, skipping '
 101                   'resizing of media {1}.'.format(keyname, entry.id))
 102         return
 103
 104     # If the size of the original file exceeds the specified size for the desized
 105     # file, a target_name file is created and later associated with the media
 106     # entry.
 107     # Also created if the file needs rotation, or if forced.
 108     try:
 109         im = Image.open(orig_file)
 110     except IOError:
 111         raise BadMediaFail()
 112     if force \
 113         or im.size[0] > new_size[0]\
 114         or im.size[1] > new_size[1]\
 115         or exif_image_needs_rotation(exif_tags):
 116         resize_image(
 117             entry, im, unicode(keyname), target_name,
 118             tuple(new_size),
 119             exif_tags, conversions_subdir,
 120             quality, filter)
 121
 122
 123 def _skip_resizing(entry, keyname, size, quality, filter):
 124     """
 125     Determines wither the saved thumb or medium is of the same quality and size
 126     """
 127     image_info = entry.get_file_metadata(keyname)
 128
 129     if not image_info:
 130         return False
 131
 132     skip = True
 133
 134     if image_info.get('width') != size[0]:
 135         skip = False
 136
 137     elif image_info.get('height') != size[1]:
 138         skip = False
 139
 140     elif image_info.get('filter') != filter:
 141         skip = False
 142
 143     elif image_info.get('quality') != quality:
 144         skip = False
 145
 146     return skip
 147
 148
 149 SUPPORTED_FILETYPES = ['png', 'gif', 'jpg', 'jpeg', 'tiff']
 150
 151
 152 def sniff_handler(media_file, **kw):
 153     _log.info('Sniffing {0}'.format(MEDIA_TYPE))
 154     if kw.get('media') is not None:  # That's a double negative!
 155         name, ext = os.path.splitext(kw['media'].filename)
 156         clean_ext = ext[1:].lower()  # Strip the . from ext and make lowercase
 157
 158         if clean_ext in SUPPORTED_FILETYPES:
 159             _log.info('Found file extension in supported filetypes')
 160             return MEDIA_TYPE
 161         else:
 162             _log.debug('Media present, extension not found in {0}'.format(
 163                     SUPPORTED_FILETYPES))
 164     else:
 165         _log.warning('Need additional information (keyword argument \'media\')'
 166                      ' to be able to handle sniffing')
 167
 168     return None
 169
 170
 171 class CommonImageProcessor(MediaProcessor):
 172     """
 173     Provides a base for various media processing steps
 174     """
 175     # list of acceptable file keys in order of prefrence for reprocessing
 176     acceptable_files = ['original', 'medium']
 177
 178     def common_setup(self):
 179         """
 180         Set up the workbench directory and pull down the original file
 181         """
 182         self.image_config = mgg.global_config[
 183             'media_type:mediagoblin.media_types.image']
 184
 185         ## @@: Should this be two functions?
 186         # Conversions subdirectory to avoid collisions
 187         self.conversions_subdir = os.path.join(
 188             self.workbench.dir, 'convirsions')
 189         os.mkdir(self.conversions_subdir)
 190
 191         # Pull down and set up the processing file
 192         self.process_filename = get_process_filename(
 193             self.entry, self.workbench, self.acceptable_files)
 194         self.name_builder = FilenameBuilder(self.process_filename)
 195
 196         # Exif extraction
 197         self.exif_tags = extract_exif(self.process_filename)
 198
 199     def generate_medium_if_applicable(self, size=None, quality=None,
 200                                       filter=None):
 201         if not quality:
 202             quality = self.image_config['quality']
 203         if not filter:
 204             filter = self.image_config['resize_filter']
 205
 206         resize_tool(self.entry, False, 'medium', self.process_filename,
 207                     self.name_builder.fill('{basename}.medium{ext}'),
 208                     self.conversions_subdir, self.exif_tags, quality,
 209                     filter, size)
 210
 211     def generate_thumb(self, size=None, quality=None, filter=None):
 212         if not quality:
 213             quality = self.image_config['quality']
 214         if not filter:
 215             filter = self.image_config['resize_filter']
 216
 217         resize_tool(self.entry, True, 'thumb', self.process_filename,
 218                     self.name_builder.fill('{basename}.thumbnail{ext}'),
 219                     self.conversions_subdir, self.exif_tags, quality,
 220                     filter, size)
 221
 222     def copy_original(self):
 223         copy_original(
 224             self.entry, self.process_filename,
 225             self.name_builder.fill('{basename}{ext}'))
 226
 227     def extract_metadata(self):
 228         # Is there any GPS data
 229         gps_data = get_gps_data(self.exif_tags)
 230
 231         # Insert exif data into database
 232         exif_all = clean_exif(self.exif_tags)
 233
 234         if len(exif_all):
 235             self.entry.media_data_init(exif_all=exif_all)
 236
 237         if len(gps_data):
 238             for key in list(gps_data.keys()):
 239                 gps_data['gps_' + key] = gps_data.pop(key)
 240             self.entry.media_data_init(**gps_data)
 241
 242
 243 class InitialProcessor(CommonImageProcessor):
 244     """
 245     Initial processing step for new images
 246     """
 247     name = "initial"
 248     description = "Initial processing"
 249
 250     @classmethod
 251     def media_is_eligible(cls, entry=None, state=None):
 252         """
 253         Determine if this media type is eligible for processing
 254         """
 255         if not state:
 256             state = entry.state
 257         return state in (
 258             "unprocessed", "failed")
 259
 260     ###############################
 261     # Command line interface things
 262     ###############################
 263
 264     @classmethod
 265     def generate_parser(cls):
 266         parser = argparse.ArgumentParser(
 267             description=cls.description,
 268             prog=cls.name)
 269
 270         parser.add_argument(
 271             '--size',
 272             nargs=2,
 273             metavar=('max_width', 'max_height'),
 274             type=int)
 275
 276         parser.add_argument(
 277             '--thumb-size',
 278             nargs=2,
 279             metavar=('max_width', 'max_height'),
 280             type=int)
 281
 282         parser.add_argument(
 283             '--filter',
 284             choices=['BICUBIC', 'BILINEAR', 'NEAREST', 'ANTIALIAS'])
 285
 286         parser.add_argument(
 287             '--quality',
 288             type=int,
 289             help='level of compression used when resizing images')
 290
 291         return parser
 292
 293     @classmethod
 294     def args_to_request(cls, args):
 295         return request_from_args(
 296             args, ['size', 'thumb_size', 'filter', 'quality'])
 297
 298     def process(self, size=None, thumb_size=None, quality=None, filter=None):
 299         self.common_setup()
 300         self.generate_medium_if_applicable(size=size, filter=filter,
 301                                            quality=quality)
 302         self.generate_thumb(size=thumb_size, filter=filter, quality=quality)
 303         self.copy_original()
 304         self.extract_metadata()
 305         self.delete_queue_file()
 306
 307
 308 class Resizer(CommonImageProcessor):
 309     """
 310     Resizing process steps for processed media
 311     """
 312     name = 'resize'
 313     description = 'Resize image'
 314     thumb_size = 'size'
 315
 316     @classmethod
 317     def media_is_eligible(cls, entry=None, state=None):
 318         """
 319         Determine if this media type is eligible for processing
 320         """
 321         if not state:
 322             state = entry.state
 323         return state in 'processed'
 324
 325     ###############################
 326     # Command line interface things
 327     ###############################
 328
 329     @classmethod
 330     def generate_parser(cls):
 331         parser = argparse.ArgumentParser(
 332             description=cls.description,
 333             prog=cls.name)
 334
 335         parser.add_argument(
 336             '--size',
 337             nargs=2,
 338             metavar=('max_width', 'max_height'),
 339             type=int)
 340
 341         parser.add_argument(
 342             '--filter',
 343             choices=['BICUBIC', 'BILINEAR', 'NEAREST', 'ANTIALIAS'])
 344
 345         parser.add_argument(
 346             '--quality',
 347             type=int,
 348             help='level of compression used when resizing images')
 349
 350         parser.add_argument(
 351             'file',
 352             choices=['medium', 'thumb'])
 353
 354         return parser
 355
 356     @classmethod
 357     def args_to_request(cls, args):
 358         return request_from_args(
 359             args, ['size', 'file', 'quality', 'filter'])
 360
 361     def process(self, file, size=None, filter=None, quality=None):
 362         self.common_setup()
 363         if file == 'medium':
 364             self.generate_medium_if_applicable(size=size, filter=filter,
 365                                               quality=quality)
 366         elif file == 'thumb':
 367             self.generate_thumb(size=size, filter=filter, quality=quality)
 368
 369
 370 class ImageProcessingManager(ProcessingManager):
 371     def __init__(self):
 372         super(self.__class__, self).__init__()
 373         self.add_processor(InitialProcessor)
 374         self.add_processor(Resizer)
 375
 376
 377 if __name__ == '__main__':
 378     import sys
 379     import pprint
 380
 381     pp = pprint.PrettyPrinter()
 382
 383     result = extract_exif(sys.argv[1])
 384     gps = get_gps_data(result)
 385     clean = clean_exif(result)
 386     useful = get_useful(clean)
 387
 388     print pp.pprint(
 389         clean)