Image.point tests for Float LUT

Tests/test_image_point.py

@@ -31,6 +31,16 @@ class TestImagePoint(PillowTestCase):
         im = lena("I")
         im.point(list(range(256))*256, 'L')
 
+    def test_f_lut(self):
+        """ Tests for floating point lut of 8bit gray image """
+        im = lena('L')
+        lut = [0.5 * float(x) for x in range(256)]
+
+        out = im.point(lut, 'F')
+
+        int_lut = [x//2 for x in range(256)]
+        self.assert_image_equal(out.convert('L'), im.point(int_lut, 'L'))
+        
 
 if __name__ == '__main__':
     unittest.main()