Use truth value when checking for optimize option on save

PIL/JpegImagePlugin.py

@@ -688,12 +688,14 @@ def _save(im, fp, filename):
     progressive = info.get("progressive", False) or\
                   info.get("progression", False)
 
+    optimize = info.get("optimize", False)
+
     # get keyword arguments
     im.encoderconfig = (
         quality,
         progressive,
         info.get("smooth", 0),
-        "optimize" in info,
+        optimize,
         info.get("streamtype", 0),
         dpi[0], dpi[1],
         subsampling,
@@ -707,7 +709,7 @@ def _save(im, fp, filename):
     # channels*size, this is a value that's been used in a django patch.
     # https://github.com/matthewwithanm/django-imagekit/issues/50
     bufsize = 0
-    if "optimize" in info or progressive:
+    if optimize or progressive:
         # keep sets quality to 0, but the actual value may be high.
         if quality >= 95 or quality == 0:
             bufsize = 2 * im.size[0] * im.size[1]

PIL/PngImagePlugin.py

@@ -696,15 +696,10 @@ def _save(im, fp, filename, chunk=putchunk, check=0):
             mode = "%s;%d" % (mode, bits)
 
     # encoder options
-    if "dictionary" in im.encoderinfo:
-        dictionary = im.encoderinfo["dictionary"]
-    else:
-        dictionary = b""
-
-    im.encoderconfig = ("optimize" in im.encoderinfo,
+    im.encoderconfig = (im.encoderinfo.get("optimize", False),
                         im.encoderinfo.get("compress_level", -1),
                         im.encoderinfo.get("compress_type", -1),
-                        dictionary)
+                        im.encoderinfo.get("dictionary", b""))
 
     # get the corresponding PNG mode
     try:

Tests/test_file_jpeg.py

@@ -126,9 +126,12 @@ class TestFileJpeg(PillowTestCase):
 
     def test_optimize(self):
         im1 = self.roundtrip(hopper())
-        im2 = self.roundtrip(hopper(), optimize=1)
+        im2 = self.roundtrip(hopper(), optimize=0)
+        im3 = self.roundtrip(hopper(), optimize=1)
         self.assert_image_equal(im1, im2)
+        self.assert_image_equal(im1, im3)
         self.assertGreaterEqual(im1.bytes, im2.bytes)
+        self.assertGreaterEqual(im1.bytes, im3.bytes)
 
     def test_optimize_large_buffer(self):
         # https://github.com/python-pillow/Pillow/issues/148
@@ -139,9 +142,14 @@ class TestFileJpeg(PillowTestCase):
 
     def test_progressive(self):
         im1 = self.roundtrip(hopper())
-        im2 = self.roundtrip(hopper(), progressive=True)
-        self.assert_image_equal(im1, im2)
-        self.assertGreaterEqual(im1.bytes, im2.bytes)
+        im2 = self.roundtrip(hopper(), progressive=False)
+        im3 = self.roundtrip(hopper(), progressive=True)
+        self.assertFalse(im1.info.get("progressive"))
+        self.assertFalse(im2.info.get("progressive"))
+        self.assertTrue(im3.info.get("progressive"))
+
+        self.assert_image_equal(im1, im3)
+        self.assertGreaterEqual(im1.bytes, im3.bytes)
 
     def test_progressive_large_buffer(self):
         f = self.tempfile('temp.jpg')