mediagoblin/tests/test_exif.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 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 os
  18 import pkg_resources
  19 import Image
  20
  21 from mediagoblin.tools.exif import exif_fix_image_orientation, \
  22     extract_exif, clean_exif, get_gps_data, get_useful
  23
  24 GOOD_JPG = pkg_resources.resource_filename(
  25     'mediagoblin.tests',
  26     os.path.join(
  27         'test_exif',
  28         'good.jpg'))
  29 EMPTY_JPG = pkg_resources.resource_filename(
  30     'mediagoblin.tests',
  31     os.path.join(
  32         'test_exif',
  33         'empty.jpg'))
  34 BAD_JPG = pkg_resources.resource_filename(
  35     'mediagoblin.tests',
  36     os.path.join(
  37         'test_exif',
  38         'bad.jpg'))
  39 GPS_JPG = pkg_resources.resource_filename(
  40     'mediagoblin.tests',
  41     os.path.join(
  42         'test_exif',
  43         'has-gps.jpg'))
  44
  45 def test_exif_extraction():
  46     '''
  47     Test EXIF extraction from a good image
  48     '''
  49     result = extract_exif(GOOD_JPG)
  50     clean = clean_exif(result)
  51     useful = get_useful(clean)
  52     gps = get_gps_data(result)
  53
  54     # Do we have the result?
  55     assert len(result) == 108
  56
  57     # Do we have clean data?
  58     assert len(clean) == 105
  59
  60     # GPS data?
  61     assert gps == {}
  62
  63     # Do we have the "useful" tags?
  64     assert useful == {
  65         'EXIF Flash': {
  66             'field_type': 3,
  67             'printable': 'No',
  68             'field_offset': 380,
  69             'tag': 37385,
  70             'values': [0],
  71             'field_length': 2},
  72         'EXIF ExposureTime': {
  73             'field_type': 5,
  74             'printable': '1/125',
  75             'field_offset': 700,
  76             'tag': 33434,
  77             'values': [[1, 125]],
  78             'field_length': 8},
  79         'EXIF FocalLength': {
  80             'field_type': 5,
  81             'printable': '18',
  82             'field_offset': 780,
  83             'tag': 37386,
  84             'values': [[18, 1]],
  85             'field_length': 8},
  86         'Image Model': {
  87             'field_type': 2,
  88             'printable': 'NIKON D80',
  89             'field_offset': 152,
  90             'tag': 272,
  91             'values': 'NIKON D80',
  92             'field_length': 10},
  93         'Image Make': {
  94             'field_type': 2,
  95             'printable': 'NIKON CORPORATION',
  96             'field_offset': 134,
  97             'tag': 271,
  98             'values': 'NIKON CORPORATION',
  99             'field_length': 18},
 100         'EXIF ExposureMode': {
 101             'field_type': 3,
 102             'printable': 'Manual Exposure',
 103             'field_offset': 584,
 104             'tag': 41986,
 105             'values': [1],
 106             'field_length': 2},
 107         'EXIF ISOSpeedRatings': {
 108             'field_type': 3,
 109             'printable': '100',
 110             'field_offset': 260,
 111             'tag': 34855,
 112             'values': [100],
 113             'field_length': 2},
 114         'EXIF FNumber': {
 115             'field_type': 5,
 116             'printable': '10',
 117             'field_offset': 708,
 118             'tag': 33437,
 119             'values': [[10, 1]],
 120             'field_length': 8},
 121         'EXIF UserComment': {
 122             'field_type': 7,
 123             'printable': 'Joar Wandborg                       ',
 124             'field_offset': 26180,
 125             'tag': 37510,
 126             'values': [
 127                 65, 83, 67, 73, 73, 0, 0, 0, 74, 111, 97, 114, 32, 87,
 128                 97, 110, 100, 98, 111, 114, 103, 32, 32, 32, 32, 32, 32,
 129                 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
 130                 32, 32, 32],
 131             'field_length': 44}}
 132
 133 def test_exif_image_orientation():
 134     '''
 135     Test image reorientation based on EXIF data
 136     '''
 137     result = extract_exif(GOOD_JPG)
 138
 139     image = exif_fix_image_orientation(
 140         Image.open(GOOD_JPG),
 141         result)
 142
 143     # Are the dimensions correct?
 144     assert image.size == (428, 640)
 145
 146     # If this pixel looks right, the rest of the image probably will too.
 147     assert image.getdata()[10000] == (41, 28, 11)
 148
 149 def test_exif_no_exif():
 150     '''
 151     Test an image without exif
 152     '''
 153     result = extract_exif(EMPTY_JPG)
 154     clean = clean_exif(result)
 155     useful = get_useful(clean)
 156     gps = get_gps_data(result)
 157
 158     assert result == {}
 159     assert clean == {}
 160     assert gps == {}
 161     assert useful == {}
 162
 163 def test_exif_bad_image():
 164     '''
 165     Test EXIF extraction from a faithful, but bad image
 166     '''
 167     result = extract_exif(BAD_JPG)
 168     clean = clean_exif(result)
 169     useful = get_useful(clean)
 170     gps = get_gps_data(result)
 171
 172     assert result == {}
 173     assert clean == {}
 174     assert gps == {}
 175     assert useful == {}
 176
 177 def test_exif_gps_data():
 178     '''
 179     Test extractiion of GPS data
 180     '''
 181     result = extract_exif(GPS_JPG)
 182     gps = get_gps_data(result)
 183
 184     assert gps == {
 185         'latitude': 59.336666666666666,
 186         'direction': 25.674046740467404,
 187         'altitude': 37.64365671641791,
 188         'longitude': 18.016166666666667}
 189