From 2724f50b4c23aed4446688f4107bdc55d960165e Mon Sep 17 00:00:00 2001
From: James Bergstra <james.bergstra@gmail.com>
Date: Sat, 18 Aug 2012 10:12:22 -0400
Subject: [PATCH] FIX: added default identity matrix to SimilarityTransform to
 match AffineTransform

---
 skimage/transform/_geometric.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/skimage/transform/_geometric.py b/skimage/transform/_geometric.py
index 51ff9519..90a3ab57 100644
--- a/skimage/transform/_geometric.py
+++ b/skimage/transform/_geometric.py
@@ -298,10 +298,8 @@ class AffineTransform(ProjectiveTransform):
             ])
             self._matrix[0:2, 2] = translation
         else:
-            # -- Default to an identity transform
-            self._matrix = np.asarray(
-                    [[1, 0, 0], [0, 1, 0], [0, 0, 0]],
-                    dtype='float64')
+            # Default to an identity transform
+            self._matrix = np.eye(3)
 
     @property
     def scale(self):
@@ -377,6 +375,9 @@ class SimilarityTransform(ProjectiveTransform):
             ])
             self._matrix *= scale
             self._matrix[0:2, 2] = translation
+        else:
+            # Default to an identity transform
+            self._matrix = np.eye(3)
 
     def estimate(self, src, dst):
         """Set the transformation matrix with the explicit parameters.