diff --git a/python/test_arithmetic.py b/python/test_arithmetic.py
index 7e6df0e9..ee480922 100755
--- a/python/test_arithmetic.py
+++ b/python/test_arithmetic.py
@@ -481,5 +481,73 @@ class TestArithmetic(unittest.TestCase):
 
         self.run_unary(self.all_images, my_exp10, fmt = noncomplex_formats)
 
+    def test_max(self):
+        test = Vips.Image.black(100, 100).draw_rect(100, 40, 50, 1, 1)
+
+        for fmt in all_formats:
+            v = test.cast(fmt).max()
+
+            self.assertAlmostEqual(v, 100)
+            v, x, y = test.cast(fmt).maxpos()
+            self.assertAlmostEqual(v, 100)
+            self.assertAlmostEqual(x, 40)
+            self.assertAlmostEqual(y, 50)
+
+    def test_min(self):
+        test = (Vips.Image.black(100, 100) + 100).draw_rect(0, 40, 50, 1, 1)
+
+        for fmt in all_formats:
+            v = test.cast(fmt).min()
+
+            self.assertAlmostEqual(v, 0)
+            v, x, y = test.cast(fmt).minpos()
+            self.assertAlmostEqual(v, 0)
+            self.assertAlmostEqual(x, 40)
+            self.assertAlmostEqual(y, 50)
+
+    def test_measure(self):
+        im = Vips.Image.black(50, 50)
+        test = im.insert(im + 10, 50, 0, expand = True)
+
+        for x in noncomplex_formats:
+            a = test.cast(x)
+            matrix = a.measure(2, 1)
+            [p1] = matrix.getpoint(0, 0)
+            [p2] = matrix.getpoint(0, 1)
+
+            self.assertAlmostEqual(p1, 0)
+            self.assertAlmostEqual(p2, 10)
+
+    def test_profile(self):
+        test = Vips.Image.black(100, 100).draw_rect(100, 40, 50, 1, 1)
+
+        for fmt in noncomplex_formats:
+            columns, rows = test.cast(fmt).profile()
+
+            v, x, y = columns.minpos()
+            self.assertAlmostEqual(v, 50)
+            self.assertAlmostEqual(x, 40)
+            self.assertAlmostEqual(y, 0)
+
+            v, x, y = rows.minpos()
+            self.assertAlmostEqual(v, 40)
+            self.assertAlmostEqual(x, 0)
+            self.assertAlmostEqual(y, 50)
+
+    def test_project(self):
+        im = Vips.Image.black(50, 50)
+        test = im.insert(im + 10, 50, 0, expand = True)
+
+        for fmt in noncomplex_formats:
+            columns, rows = test.cast(fmt).project()
+
+            self.assertAlmostEqualObjects(columns.getpoint(10,0), [0])
+            self.assertAlmostEqualObjects(columns.getpoint(70,0), [50 * 10])
+
+            self.assertAlmostEqualObjects(rows.getpoint(0,10), [50 * 10])
+
+
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/python/vips8/vips.py b/python/vips8/vips.py
index 167f7442..e187a6b0 100644
--- a/python/vips8/vips.py
+++ b/python/vips8/vips.py
@@ -159,7 +159,7 @@ def _call_base(name, required, optional, self = None, option_string = None):
                       not x.flags & enm.REQUIRED and 
                       not x.isset}
 
-    # and the names of all optional output args ... we use "x = True" 
+    # find all optional output args ... we use "x = True" 
     # in args to mean add that to output
     optional_output = {x.name: x for x in args if x.flags & enm.OUTPUT and 
                        not x.flags & enm.REQUIRED}
@@ -182,9 +182,12 @@ def _call_base(name, required, optional, self = None, option_string = None):
     if op2 == None:
         raise Error('Error calling operator %s.' % name)
 
-    # rescan args, op2 has changed
-    args = [Argument(op2, x) for x in op2.props]
-    args.sort(lambda a, b: a.priority - b.priority)
+    # rescan args if op2 is different from op
+    if op2 != op:
+        args = [Argument(op2, x) for x in op2.props]
+        args.sort(lambda a, b: a.priority - b.priority)
+        optional_output = {x.name: x for x in args if x.flags & enm.OUTPUT and 
+                           not x.flags & enm.REQUIRED}
 
     # gather output args 
     out = []
@@ -415,6 +418,12 @@ def vips_xor(self, other):
     else:
         return self.boolean_const(other, Vips.OperationBoolean.EOR)
 
+def vips_more(self, other):
+    if isinstance(other, Vips.Image):
+        return self.relational(other, Vips.OperationRelational.MORE)
+    else:
+        return self.relational_const(Vips.OperationRelational.MORE, other)
+
 def vips_neg(self):
     return -1 * self
 
@@ -556,8 +565,11 @@ Vips.Image.__rdiv__ = vips_rdiv
 Vips.Image.__floordiv__ = vips_floordiv
 Vips.Image.__rfloordiv__ = vips_rfloordiv
 Vips.Image.__mod__ = vips_mod
+
 Vips.Image.__pow__ = vips_pow
 Vips.Image.__rpow__ = vips_rpow
+Vips.Image.__abs__ = vips_abs
+
 Vips.Image.__lshift__ = vips_lshift
 Vips.Image.__rshift__ = vips_rshift
 Vips.Image.__and__ = vips_and
@@ -566,11 +578,18 @@ Vips.Image.__or__ = vips_or
 Vips.Image.__ror__ = vips_or
 Vips.Image.__xor__ = vips_xor
 Vips.Image.__rxor__ = vips_xor
+
 Vips.Image.__neg__ = vips_neg
 Vips.Image.__pos__ = vips_pos
-Vips.Image.__abs__ = vips_abs
 Vips.Image.__invert__ = vips_invert
 
+Vips.Image.__lt__ = vips_less
+Vips.Image.__le__ = vips_lesseq
+Vips.Image.__gt__ = vips_more
+Vips.Image.__ge__ = vips_moreeq
+Vips.Image.__eq__ = vips_equal
+Vips.Image.__ne__ = vips_notequal
+
 # the cast operators int(), long() and float() must return numeric types, so we
 # can't define them for images