From 28ee215c6cc0f10c55f63220894618d2f09934f8 Mon Sep 17 00:00:00 2001
From: Patrick Kaifosh <pwk2108@columbia.edu>
Date: Fri, 16 Jan 2015 14:09:05 -0500
Subject: [PATCH] Created Transform class for motion correction

---
 sima/motion/transform.py | 54 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 sima/motion/transform.py

diff --git a/sima/motion/transform.py b/sima/motion/transform.py
new file mode 100644
index 0000000..df2c525
--- /dev/null
+++ b/sima/motion/transform.py
@@ -0,0 +1,54 @@
+import abc
+
+
+class Transform(object):
+    """Abstract class for geometric transforms."""
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def apply(self, source, grid=None):
+        """Apply the transform to raw source data.
+
+        Parameters
+        ----------
+        source : np.ndarray
+        grid :
+
+        Returns
+        -------
+        transformed : np.ndarray
+        """
+        pass
+
+
+class InvertibleTransform(Transform):
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def inverse(self):
+        pass
+
+
+class DifferentiableTransform(Transform):
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def jacobian(self):
+        pass
+
+
+class NullTransform(Transform):
+    """Class to represent a null transform.
+
+    This may be useful to indicate that a transform could not be estimated.
+    It could return a grid of all NaN values when applied.
+    """
+    pass
+
+
+class Identity(Transform):
+    pass
+
+
+class WithinFrameTranslation(Transform):
+    pass