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
  80 def resize_tool(entry,
  81                 force, keyname, orig_file, target_name,
  82                 conversions_subdir, exif_tags, quality, filter, new_size=None):
  83     # Use the default size if new_size was not given
  84     if not new_size:
  85         max_width = mgg.global_config['media:' + keyname]['max_width']
  86         max_height = mgg.global_config['media:' + keyname]['max_height']
  87         new_size = (max_width, max_height)
  88
  89     # If the size of the original file exceeds the specified size for the desized
  90     # file, a target_name file is created and later associated with the media
  91     # entry.
  92     # Also created if the file needs rotation, or if forced.
  93     try:
  94         im = Image.open(orig_file)
  95     except IOError:
  96         raise BadMediaFail()
  97     if force \
  98         or im.size[0] > new_size[0]\
  99         or im.size[1] > new_size[1]\
 100         or exif_image_needs_rotation(exif_tags):
 101         resize_image(
 102             entry, im, unicode(keyname), target_name,
 103             new_size,
 104             exif_tags, conversions_subdir,
 105             quality, filter)
 106
 107
 108 SUPPORTED_FILETYPES = ['png', 'gif', 'jpg', 'jpeg', 'tiff']
 109
 110
 111 def sniff_handler(media_file, **kw):
 112     _log.info('Sniffing {0}'.format(MEDIA_TYPE))
 113     if kw.get('media') is not None:  # That's a double negative!
 114         name, ext = os.path.splitext(kw['media'].filename)
 115         clean_ext = ext[1:].lower()  # Strip the . from ext and make lowercase
 116
 117         if clean_ext in SUPPORTED_FILETYPES:
 118             _log.info('Found file extension in supported filetypes')
 119             return MEDIA_TYPE
 120         else:
 121             _log.debug('Media present, extension not found in {0}'.format(
 122                     SUPPORTED_FILETYPES))
 123     else:
 124         _log.warning('Need additional information (keyword argument \'media\')'
 125                      ' to be able to handle sniffing')
 126
 127     return None
 128
 129
 130 class CommonImageProcessor(MediaProcessor):
 131     """
 132     Provides a base for various media processing steps
 133     """
 134     # list of acceptable file keys in order of prefrence for reprocessing
 135     acceptable_files = ['original', 'medium']
 136
 137     def common_setup(self):
 138         """
 139         Set up the workbench directory and pull down the original file
 140         """
 141         self.image_config = mgg.global_config[
 142             'media_type:mediagoblin.media_types.image']
 143
 144         ## @@: Should this be two functions?
 145         # Conversions subdirectory to avoid collisions
 146         self.conversions_subdir = os.path.join(
 147             self.workbench.dir, 'convirsions')
 148         os.mkdir(self.conversions_subdir)
 149
 150         # Pull down and set up the processing file
 151         self.process_filename = get_process_filename(
 152             self.entry, self.workbench, self.acceptable_files)
 153         self.name_builder = FilenameBuilder(self.process_filename)
 154
 155         # Exif extraction
 156         self.exif_tags = extract_exif(self.process_filename)
 157
 158     def generate_medium_if_applicable(self, size=None, quality=None,
 159                                       filter=None):
 160         if not quality:
 161             quality = self.image_config['quality']
 162         if not filter:
 163             filter = self.image_config['resize_filter']
 164
 165         resize_tool(self.entry, False, 'medium', self.process_filename,
 166                     self.name_builder.fill('{basename}.medium{ext}'),
 167                     self.conversions_subdir, self.exif_tags, quality,
 168                     filter, size)
 169
 170     def generate_thumb(self, size=None, quality=None, filter=None):
 171         if not quality:
 172             quality = self.image_config['quality']
 173         if not filter:
 174             filter = self.image_config['resize_filter']
 175
 176         resize_tool(self.entry, True, 'thumb', self.process_filename,
 177                     self.name_builder.fill('{basename}.thumbnail{ext}'),
 178                     self.conversions_subdir, self.exif_tags, quality,
 179                     filter, size)
 180
 181     def copy_original(self):
 182         copy_original(
 183             self.entry, self.process_filename,
 184             self.name_builder.fill('{basename}{ext}'))
 185
 186     def extract_metadata(self):
 187         # Is there any GPS data
 188         gps_data = get_gps_data(self.exif_tags)
 189
 190         # Insert exif data into database
 191         exif_all = clean_exif(self.exif_tags)
 192
 193         if len(exif_all):
 194             self.entry.media_data_init(exif_all=exif_all)
 195
 196         if len(gps_data):
 197             for key in list(gps_data.keys()):
 198                 gps_data['gps_' + key] = gps_data.pop(key)
 199             self.entry.media_data_init(**gps_data)
 200
 201
 202 class InitialProcessor(CommonImageProcessor):
 203     """
 204     Initial processing step for new images
 205     """
 206     name = "initial"
 207     description = "Initial processing"
 208
 209     @classmethod
 210     def media_is_eligible(cls, entry=None, state=None):
 211         """
 212         Determine if this media type is eligible for processing
 213         """
 214         if not state:
 215             state = entry.state
 216         return state in (
 217             "unprocessed", "failed")
 218
 219     ###############################
 220     # Command line interface things
 221     ###############################
 222
 223     @classmethod
 224     def generate_parser(cls):
 225         parser = argparse.ArgumentParser(
 226             description=cls.description,
 227             prog=cls.name)
 228
 229         parser.add_argument(
 230             '--size',
 231             nargs=2,
 232             metavar=('max_width', 'max_height'),
 233             type=int)
 234
 235         parser.add_argument(
 236             '--thumb-size',
 237             nargs=2,
 238             metavar=('max_width', 'max_height'),
 239             type=int)
 240
 241         parser.add_argument(
 242             '--filter',
 243             choices=['BICUBIC', 'BILINEAR', 'NEAREST', 'ANTIALIAS'])
 244
 245         parser.add_argument(
 246             '--quality',
 247             type=int,
 248             help='level of compression used when resizing images')
 249
 250         return parser
 251
 252     @classmethod
 253     def args_to_request(cls, args):
 254         return request_from_args(
 255             args, ['size', 'thumb_size', 'filter', 'quality'])
 256
 257     def process(self, size=None, thumb_size=None, quality=None, filter=None):
 258         self.common_setup()
 259         self.generate_medium_if_applicable(size=size, filter=filter,
 260                                            quality=quality)
 261         self.generate_thumb(size=thumb_size, filter=filter, quality=quality)
 262         self.copy_original()
 263         self.extract_metadata()
 264         self.delete_queue_file()
 265
 266
 267 class Resizer(CommonImageProcessor):
 268     """
 269     Resizing process steps for processed media
 270     """
 271     name = 'resize'
 272     description = 'Resize image'
 273     thumb_size = 'size'
 274
 275     @classmethod
 276     def media_is_eligible(cls, entry=None, state=None):
 277         """
 278         Determine if this media type is eligible for processing
 279         """
 280         if not state:
 281             state = entry.state
 282         return state in 'processed'
 283
 284     ###############################
 285     # Command line interface things
 286     ###############################
 287
 288     @classmethod
 289     def generate_parser(cls):
 290         parser = argparse.ArgumentParser(
 291             description=cls.description,
 292             prog=cls.name)
 293
 294         parser.add_argument(
 295             '--size',
 296             nargs=2,
 297             metavar=('max_width', 'max_height'),
 298             type=int)
 299
 300         parser.add_argument(
 301             '--filter',
 302             choices=['BICUBIC', 'BILINEAR', 'NEAREST', 'ANTIALIAS'])
 303
 304         parser.add_argument(
 305             '--quality',
 306             type=int,
 307             help='level of compression used when resizing images')
 308
 309         parser.add_argument(
 310             'file',
 311             choices=['medium', 'thumb'])
 312
 313         return parser
 314
 315     @classmethod
 316     def args_to_request(cls, args):
 317         return request_from_args(
 318             args, ['size', 'file', 'quality', 'filter'])
 319
 320     def process(self, file, size=None, filter=None, quality=None):
 321         self.common_setup()
 322         if file == 'medium':
 323             self.generate_medium_if_applicable(size=size, filter=filter,
 324                                               quality=quality)
 325         elif file == 'thumb':
 326             self.generate_thumb(size=size, filter=filter, quality=quality)
 327
 328
 329 class ImageProcessingManager(ProcessingManager):
 330     def __init__(self):
 331         super(self.__class__, self).__init__()
 332         self.add_processor(InitialProcessor)
 333         self.add_processor(Resizer)
 334
 335
 336 if __name__ == '__main__':
 337     import sys
 338     import pprint
 339
 340     pp = pprint.PrettyPrinter()
 341
 342     result = extract_exif(sys.argv[1])
 343     gps = get_gps_data(result)
 344     clean = clean_exif(result)
 345     useful = get_useful(clean)
 346
 347     print pp.pprint(
 348         clean)