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