Made JPEG2K support for files conditional on its inclusion in pillow build. Added a JPEG2K icon test.

PIL/IcnsImagePlugin.py

@@ -15,9 +15,13 @@
 # See the README file for information on usage and redistribution.
 #
 
-from PIL import Image, ImageFile, PngImagePlugin, Jpeg2KImagePlugin, _binary
+from PIL import Image, ImageFile, PngImagePlugin, _binary
 import struct, io
 
+enable_jpeg2k = hasattr(Image.core, 'jp2klib_version')
+if enable_jpeg2k:
+    import Jpeg2KImagePlugin
+
 i8 = _binary.i8
 
 HEADERSIZE = 8
@@ -101,6 +105,8 @@ def read_png_or_jpeg2000(fobj, start_length, size):
     elif sig[:4] == b'\xff\x4f\xff\x51' \
         or sig[:4] == b'\x0d\x0a\x87\x0a' \
         or sig == b'\x00\x00\x00\x0cjP  \x0d\x0a\x87\x0a':
+        if not enable_jpeg2k:
+            raise ValueError('Unsupported icon subimage format (rebuild PIL with JPEG 2000 support to fix this)')
         # j2k, jpc or j2c
         fobj.seek(start)
         jp2kstream = fobj.read(length)
@@ -109,6 +115,8 @@ def read_png_or_jpeg2000(fobj, start_length, size):
         if im.mode != 'RGBA':
             im = im.convert('RGBA')
         return {"RGBA": im}
+    else:
+        raise ValueError('Unsupported icon subimage format')
 
 class IcnsFile:
 

Tests/test_file_icns.py

@@ -6,6 +6,8 @@ from PIL import Image
 file = "Images/pillow.icns"
 data = open(file, "rb").read()
 
+enable_jpeg2k = hasattr(Image.core, 'jp2klib_version')
+
 def test_sanity():
     # Loading this icon by default should result in the largest size
     # (512x512@2x) being loaded
@@ -40,3 +42,25 @@ def test_older_icon():
         im2.load()
         assert_equal(im2.mode, 'RGBA')
         assert_equal(im2.size, (wr, hr))
+
+def test_jp2_icon():
+    # This icon was made by using Uli Kusterer's oldiconutil to replace
+    # the PNG images with JPEG 2000 ones.  The advantage of doing this is
+    # that OS X 10.5 supports JPEG 2000 but not PNG; some commercial
+    # software therefore does just this.
+    
+    # (oldiconutil is here: https://github.com/uliwitness/oldiconutil)
+
+    if not enable_jpeg2k:
+        return
+    
+    im = Image.open('Tests/images/pillow3.icns')
+    for w,h,r in im.info['sizes']:
+        wr = w * r
+        hr = h * r
+        im2 = Image.open('Tests/images/pillow3.icns')
+        im2.size = (w, h, r)
+        im2.load()
+        assert_equal(im2.mode, 'RGBA')
+        assert_equal(im2.size, (wr, hr))
+