Populate title & description from IPTC image data

The IPTC spec defines title and description fields so use those
to populate these fields on the Image unless they've been set by
some other means.

AUTHORS

@@ -13,6 +13,7 @@ alphabetical order):
 - Christophe-Marie Duquesne
 - @datro
 - David Siroky
+- Edwin Steele
 - François D. (@franek)
 - Giel van Schijndel
 - Jamie Starke

sigal/gallery.py

@@ -5,6 +5,7 @@
 # Copyright (c) 2014      - Jonas Kaufmann
 # Copyright (c) 2015      - François D.
 # Copyright (c) 2017      - Mate Lakat
+# Copyright (c) 2018      - Edwin Steele
 
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to
@@ -42,7 +43,8 @@ from os.path import isfile, join, splitext
 
 from . import image, video, signals
 from .compat import PY2, UnicodeMixin, strxfrm, url_quote, text_type, pickle
-from .image import process_image, get_exif_tags, get_exif_data, get_size
+from .image import (process_image, get_exif_tags, get_exif_data, get_size,
+                    get_iptc_data)
 from .settings import get_thumb
 from .utils import (Devnull, copy, check_or_create_dir, url_from_path,
                     read_markdown, cached_property, is_valid_html5_video,
@@ -165,6 +167,23 @@ class Image(Media):
         return (get_exif_tags(self.raw_exif, datetime_format=datetime_format)
                 if self.raw_exif and self.ext in ('.jpg', '.jpeg') else None)
 
+    def _get_metadata(self):
+        super(Image, self)._get_metadata()
+        # If a title or description hasn't been obtained by other means, look
+        #  for the information in IPTC fields as catalogued in:
+        # https://www.iptc.org/std/photometadata/specification/IPTC-PhotoMetadata
+        if not self.title or not self.description:
+            iptc_data = get_iptc_data(self.src_path)
+            if iptc_data and not self.title:
+                # 2:05 is the IPTC title property
+                if (2, 5) in iptc_data:
+                    self.title = iptc_data[(2, 5)].decode('utf-8')
+
+            if iptc_data and not self.description:
+                # 2:120 is the IPTC description property
+                if (2, 120) in iptc_data:
+                    self.description = iptc_data[(2, 120)].decode('utf-8')
+
     @cached_property
     def raw_exif(self):
         try:

sigal/image.py

@@ -2,6 +2,7 @@
 
 # Copyright (c) 2009-2016 - Simon Conseil
 # Copyright (c) 2015 - François D.
+# Copyright (c) 2018 - Edwin Steele
 
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to
@@ -43,6 +44,7 @@ from datetime import datetime
 from PIL.ExifTags import TAGS, GPSTAGS
 from PIL import Image as PILImage
 from PIL import ImageOps
+from PIL import IptcImagePlugin
 from pilkit.processors import Transpose
 from pilkit.utils import save_image
 
@@ -235,6 +237,13 @@ def get_exif_data(filename):
     return data
 
 
+def get_iptc_data(filename):
+    """Return a dict with the raw IPTC data."""
+
+    img = _read_image(filename)
+    return IptcImagePlugin.getiptcinfo(img)
+
+
 def dms_to_degrees(v):
     """Convert degree/minute/second to decimal degrees."""
 

tests/sample/pictures/iptcTest/2.md

@@ -0,0 +1,3 @@
+Title: Markdown title beats iptc
+
+Markdown description beats iptc

tests/sample/pictures/iptcTest/index.md

@@ -0,0 +1,3 @@
+Title: iptc test gallery
+
+## This is used by test_image.py and test_gallery.py to validate iptc handling

tests/test_gallery.py

@@ -111,6 +111,22 @@ def test_media_orig(settings, tmpdir):
     assert m.big == '21.jpg'
 
 
+def test_media_iptc_override(settings):
+    img_with_md = Image('2.jpg', 'iptcTest', settings)
+    assert img_with_md.title == "Markdown title beats iptc"
+    # Markdown parsing adds formatting. Let's just focus on content
+    assert "Markdown description beats iptc" in img_with_md.description
+    img_no_md = Image('1.jpg', 'iptcTest', settings)
+    assert img_no_md.title == 'Haemostratulus clouds over Canberra - ' + \
+            '2005-12-28 at 03-25-07'
+    assert img_no_md.description == \
+            '"Haemo" because they look like haemoglobin ' + \
+            'cells and "stratulus" because I can\'t work out whether ' + \
+            'they\'re Stratus or Cumulus clouds.\nWe\'re driving down ' + \
+            'the main drag in Canberra so it\'s Parliament House that ' + \
+            'you can see at the end of the road.'
+
+
 def test_image(settings, tmpdir):
     settings['destination'] = str(tmpdir)
     settings['datetime_format'] = '%d/%m/%Y'

tests/test_image.py

@@ -7,7 +7,7 @@ from PIL import Image
 
 from sigal import init_logging
 from sigal.image import (generate_image, generate_thumbnail, get_exif_tags,
-                         get_exif_data, get_size, process_image)
+                         get_exif_data, get_size, process_image, get_iptc_data)
 from sigal.settings import create_settings, Status
 
 CURRENT_DIR = os.path.dirname(__file__)
@@ -162,6 +162,27 @@ def test_get_exif_tags():
     assert 'gps' not in simple
 
 
+def test_get_iptc_data():
+    test_image = '1.jpg'
+    src_file = os.path.join(CURRENT_DIR, 'sample', 'pictures', 'iptcTest',
+                            test_image)
+    data = get_iptc_data(src_file)
+    # Title
+    assert data[(2, 5)] == b'Haemostratulus clouds over Canberra - ' + \
+            b'2005-12-28 at 03-25-07'
+    # Description
+    assert data[(2, 120)] == b'"Haemo" because they look like haemoglobin ' + \
+            b'cells and "stratulus" because I can\'t work out whether ' + \
+            b'they\'re Stratus or Cumulus clouds.\nWe\'re driving down ' + \
+            b'the main drag in Canberra so it\'s Parliament House that ' + \
+            b'you can see at the end of the road.'
+    # This file has no IPTC data
+    test_image = '21.jpg'
+    src_file = os.path.join(CURRENT_DIR, 'sample', 'pictures', 'exifTest',
+                            test_image)
+    assert get_iptc_data(src_file) is None
+
+
 def test_iso_speed_ratings():
     data = {'ISOSpeedRatings': ()}
     simple = get_exif_tags(data)