add hardlight and softlight chops

Tests/test_imagechops.py

@@ -363,7 +363,7 @@ def test_subtract_modulo_no_clip():
         new = ImageChops.subtract_modulo(im1, im2)
 
         # Assert
-        assert new.getpixel((50, 50)) == (241, 167, 127)
+        self.assertEqual(new.getpixel((50, 50)), (241, 167, 127))
 
 
 def test_softlight(self):
@@ -392,19 +392,6 @@ def test_hardlight(self):
     self.assertEqual(new.getpixel((15, 100)), (1, 1, 2))
 
 
-def test_overlay(self):
-    # Arrange
-    im1 = Image.open("Tests/images/hopper.png")
-    im2 = Image.open("Tests/images/hopper-XYZ.png")
-
-    # Act
-    new = ImageChops.overlay(im1, im2)
-
-    # Assert
-    self.assertEqual(new.getpixel((64, 64)), (159, 50, 27))
-    self.assertEqual(new.getpixel((15, 100)), (1, 1, 2))
-
-
 def test_logical():
     def table(op, a, b):
         out = []

src/PIL/ImageChops.py

@@ -138,6 +138,27 @@ def screen(image1, image2):
     image2.load()
     return image1._new(image1.im.chop_screen(image2.im))
 
+def softlight(image1, image2):
+    """
+    Superimposes two images on top of each other using the Soft Light algorithm 
+
+    :rtype: :py:class:`~PIL.Image.Image`
+    """
+
+    image1.load()
+    image2.load()
+    return image1._new(image1.im.chop_softlight(image2.im))
+
+def hardlight(image1, image2):
+    """
+    Superimposes two images on top of each other using the Hard Light algorithm 
+
+    :rtype: :py:class:`~PIL.Image.Image`
+    """
+
+    image1.load()
+    image2.load()
+    return image1._new(image1.im.chop_hardlight(image2.im))
 
 def softlight(image1, image2):
     """