Fix JPEG saving bug: only accept the kwargs documented by PIL for JPEG files.

jkseppan · jkseppan · commit 10d939a04b9c · 2010-10-04T18:46:18.000Z
svn path=/trunk/matplotlib/; revision=8727
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,6 @@
+2010-10-04 Fix JPEG saving bug: only accept the kwargs documented
+           by PIL for JPEG files. - JKS
+
 2010-09-15 Remove unused _wxagg extension and numerix.h. - EF
 
 2010-08-25 Add new framework for doing animations with examples.- RM
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1784,7 +1784,9 @@ def print_jpg(self, filename_or_obj, *args, **kwargs):
             agg = self.switch_backends(FigureCanvasAgg)
             buf, size = agg.print_to_buffer()
             image = Image.frombuffer('RGBA', size, buf, 'raw', 'RGBA', 0, 1)
-            return image.save(filename_or_obj, **kwargs)
+            options = cbook.restrict_dict(kwargs, ['quality', 'optimize',
+                                                   'progressive'])
+            return image.save(filename_or_obj, **options)
         print_jpeg = print_jpg
 
         filetypes['tif'] = filetypes['tiff'] = 'Tagged Image File Format'
diff --git a/lib/matplotlib/cbook.py b/lib/matplotlib/cbook.py
@@ -1210,6 +1210,12 @@ def reverse_dict(d):
     'reverse the dictionary -- may lose data if values are not unique!'
     return dict([(v,k) for k,v in d.items()])
 
+def restrict_dict(d, keys):
+    """
+    Return a dictionary that contains those keys that appear in both
+    d and keys, with values from d.
+    """
+    return dict([(k,v) for (k,v) in d.iteritems() if k in keys])
 
 def report_memory(i=0):  # argument may go away
     'return the memory consumed by process'
diff --git a/lib/matplotlib/tests/test_cbook.py b/lib/matplotlib/tests/test_cbook.py
@@ -12,3 +12,18 @@ def test_is_string_like():
 
     assert cbook.is_string_like( "hello world" )
     assert_equal( cbook.is_string_like(10), False )
+
+def test_restrict_dict():
+    d = {'foo': 'bar', 1: 2}
+    d1 = cbook.restrict_dict(d, ['foo', 1])
+    assert_equal(d1, d)
+    d2 = cbook.restrict_dict(d, ['bar', 2])
+    assert_equal(d2, {})
+    d3 = cbook.restrict_dict(d, {'foo': 1})
+    assert_equal(d3, {'foo': 'bar'})
+    d4 = cbook.restrict_dict(d, {})
+    assert_equal(d4, {})
+    d5 = cbook.restrict_dict(d, set(['foo',2]))
+    assert_equal(d5, {'foo': 'bar'})
+    # check that d was not modified
+    assert_equal(d, {'foo': 'bar', 1: 2})
