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_orig_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):
  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     """
  60     config = mgg.global_config['media_type:mediagoblin.media_types.image']
  61
  62     resized = exif_fix_image_orientation(resized, exif_tags)  # Fix orientation
  63
  64     filter_config = config['resize_filter']
  65     try:
  66         resize_filter = PIL_FILTERS[filter_config.upper()]
  67     except KeyError:
  68         raise Exception('Filter "{0}" not found, choose one of {1}'.format(
  69             unicode(filter_config),
  70             u', '.join(PIL_FILTERS.keys())))
  71
  72     resized.thumbnail(new_size, resize_filter)
  73
  74     # Copy the new file to the conversion subdir, then remotely.
  75     tmp_resized_filename = os.path.join(workdir, target_name)
  76     with file(tmp_resized_filename, 'w') as resized_file:
  77         resized.save(resized_file, quality=config['quality'])
  78     store_public(entry, keyname, tmp_resized_filename, target_name)
  79
  80
  81 def resize_tool(entry,
  82                 force, keyname, orig_file, target_name,
  83                 conversions_subdir, exif_tags, new_size=None):
  84     # Use the default size if new_size was not given
  85     if not new_size:
  86         max_width = mgg.global_config['media:' + keyname]['max_width']
  87         max_height = mgg.global_config['media:' + keyname]['max_height']
  88         new_size = (max_width, max_height)
  89
  90     # If the size of the original file exceeds the specified size for the desized
  91     # file, a target_name file is created and later associated with the media
  92     # entry.
  93     # Also created if the file needs rotation, or if forced.
  94     try:
  95         im = Image.open(orig_file)
  96     except IOError:
  97         raise BadMediaFail()
  98     if force \
  99         or im.size[0] > new_size[0]\
 100         or im.size[1] > new_size[1]\
 101         or exif_image_needs_rotation(exif_tags):
 102         resize_image(
 103             entry, im, unicode(keyname), target_name,
 104             new_size,
 105             exif_tags, conversions_subdir)
 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     def common_setup(self):
 135         """
 136         Set up the workbench directory and pull down the original file
 137         """
 138         ## @@: Should this be two functions?
 139         # Conversions subdirectory to avoid collisions
 140         self.conversions_subdir = os.path.join(
 141             self.workbench.dir, 'convirsions')
 142         os.mkdir(self.conversions_subdir)
 143
 144         # Pull down and set up the original file
 145         self.orig_filename = get_orig_filename(
 146             self.entry, self.workbench)
 147         self.name_builder = FilenameBuilder(self.orig_filename)
 148
 149         # Exif extraction
 150         self.exif_tags = extract_exif(self.orig_filename)
 151
 152     def generate_medium_if_applicable(self, size=None):
 153         resize_tool(self.entry, False, 'medium', self.orig_filename,
 154                     self.name_builder.fill('{basename}.medium{ext}'),
 155                     self.conversions_subdir, self.exif_tags, size)
 156
 157     def generate_thumb(self, size=None):
 158         resize_tool(self.entry, True, 'thumb', self.orig_filename,
 159                     self.name_builder.fill('{basename}.thumbnail{ext}'),
 160                     self.conversions_subdir, self.exif_tags, size)
 161
 162     def copy_original(self):
 163         copy_original(
 164             self.entry, self.orig_filename,
 165             self.name_builder.fill('{basename}{ext}'))
 166
 167     def extract_metadata(self):
 168         # Is there any GPS data
 169         gps_data = get_gps_data(self.exif_tags)
 170
 171         # Insert exif data into database
 172         exif_all = clean_exif(self.exif_tags)
 173
 174         if len(exif_all):
 175             self.entry.media_data_init(exif_all=exif_all)
 176
 177         if len(gps_data):
 178             for key in list(gps_data.keys()):
 179                 gps_data['gps_' + key] = gps_data.pop(key)
 180             self.entry.media_data_init(**gps_data)
 181
 182
 183 class InitialProcessor(CommonImageProcessor):
 184     """
 185     Initial processing step for new images
 186     """
 187     name = "initial"
 188     description = "Initial processing"
 189
 190     @classmethod
 191     def media_is_eligible(cls, entry=None, state=None):
 192         """
 193         Determine if this media type is eligible for processing
 194         """
 195         if not state:
 196             state = entry.state
 197         return state in (
 198             "unprocessed", "failed")
 199
 200     ###############################
 201     # Command line interface things
 202     ###############################
 203
 204     @classmethod
 205     def generate_parser(cls):
 206         parser = argparse.ArgumentParser(
 207             description=cls.description,
 208             prog=cls.name)
 209
 210         parser.add_argument(
 211             '--size',
 212             nargs=2,
 213             metavar=('max_width', 'max_height'),
 214             type=int)
 215
 216         parser.add_argument(
 217             '--thumb-size',
 218             nargs=2,
 219             metavar=('max_width', 'max_height'),
 220             type=int)
 221
 222         return parser
 223
 224     @classmethod
 225     def args_to_request(cls, args):
 226         return request_from_args(
 227             args, ['size', 'thumb_size'])
 228
 229     def process(self, size=None, thumb_size=None):
 230         self.common_setup()
 231         self.generate_medium_if_applicable(size=size)
 232         self.generate_thumb(size=thumb_size)
 233         self.copy_original()
 234         self.extract_metadata()
 235         self.delete_queue_file()
 236
 237
 238 class Resizer(CommonImageProcessor):
 239     """
 240     Resizing process steps for processed media
 241     """
 242     name = 'resize'
 243     description = 'Resize image'
 244
 245     @classmethod
 246     def media_is_eligible(cls, entry=None, state=None):
 247         """
 248         Determine if this media type is eligible for processing
 249         """
 250         if not state:
 251             state = entry.state
 252         return state in 'processed'
 253
 254     ###############################
 255     # Command line interface things
 256     ###############################
 257
 258     @classmethod
 259     def generate_parser(cls):
 260         parser = argparse.ArgumentParser(
 261             description=cls.description,
 262             prog=cls.name)
 263
 264         parser.add_argument(
 265             '--size',
 266             nargs=2,
 267             metavar=('max_width', 'max_height'),
 268             type=int)
 269
 270         parser.add_argument(
 271             'file',
 272             choices=['medium', 'thumb'])
 273
 274         return parser
 275
 276     @classmethod
 277     def args_to_request(cls, args):
 278         return request_from_args(
 279             args, ['size', 'file'])
 280
 281     def process(self, file, size=None):
 282         self.common_setup()
 283         if file == 'medium':
 284             self.generate_medium_if_applicable(size=size)
 285         elif file == 'thumb':
 286             self.generate_thumb(size=size)
 287
 288
 289 class ImageProcessingManager(ProcessingManager):
 290     def __init__(self):
 291         super(self.__class__, self).__init__()
 292         self.add_processor(InitialProcessor)
 293         self.add_processor(Resizer)
 294
 295
 296 if __name__ == '__main__':
 297     import sys
 298     import pprint
 299
 300     pp = pprint.PrettyPrinter()
 301
 302     result = extract_exif(sys.argv[1])
 303     gps = get_gps_data(result)
 304     clean = clean_exif(result)
 305     useful = get_useful(clean)
 306
 307     print pp.pprint(
 308         clean)