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diff --git a/tensorflow/examples/android/jni/object_tracking/frame_pair.h b/tensorflow/examples/android/jni/object_tracking/frame_pair.h
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+/* Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef THIRD_PARTY_TENSORFLOW_EXAMPLES_ANDROID_JNI_OBJECT_TRACKING_FRAME_PAIR_H_
+#define THIRD_PARTY_TENSORFLOW_EXAMPLES_ANDROID_JNI_OBJECT_TRACKING_FRAME_PAIR_H_
+
+#include "tensorflow/examples/android/jni/object_tracking/keypoint.h"
+
+namespace tf_tracking {
+
+// A class that records keypoint correspondences from pairs of
+// consecutive frames.
+class FramePair {
+ public:
+  FramePair()
+      : start_time_(0),
+        end_time_(0),
+        number_of_keypoints_(0) {}
+
+  // Cleans up the FramePair so that they can be reused.
+  void Init(const int64 start_time, const int64 end_time);
+
+  void AdjustBox(const BoundingBox box,
+                 float* const translation_x,
+                 float* const translation_y,
+                 float* const scale_x,
+                 float* const scale_y) const;
+
+ private:
+  // Returns the weighted median of the given deltas, computed independently on
+  // x and y. Returns 0,0 in case of failure. The assumption is that a
+  // translation of 0.0 in the degenerate case is the best that can be done, and
+  // should not be considered an error.
+  //
+  // In the case of scale,  a slight exception is made just to be safe and
+  // there is a check for 0.0 explicitly, but that shouldn't ever be possible to
+  // happen naturally because of the non-zero + parity checks in FillScales.
+  Point2f GetWeightedMedian(const float* const weights,
+                            const Point2f* const deltas) const;
+
+  float GetWeightedMedianScale(const float* const weights,
+                               const Point2f* const deltas) const;
+
+  // Weights points based on the query_point and cutoff_dist.
+  int FillWeights(const BoundingBox& box,
+                  float* const weights) const;
+
+  // Fills in the array of deltas with the translations of the points
+  // between frames.
+  void FillTranslations(Point2f* const translations) const;
+
+  // Fills in the array of deltas with the relative scale factor of points
+  // relative to a given center. Has the ability to override the weight to 0 if
+  // a degenerate scale is detected.
+  // Translation is the amount the center of the box has moved from one frame to
+  // the next.
+  int FillScales(const Point2f& old_center,
+                 const Point2f& translation,
+                 float* const weights,
+                 Point2f* const scales) const;
+
+  // TODO(andrewharp): Make these private.
+ public:
+  // The time at frame1.
+  int64 start_time_;
+
+  // The time at frame2.
+  int64 end_time_;
+
+  // This array will contain the keypoints found in frame 1.
+  Keypoint frame1_keypoints_[kMaxKeypoints];
+
+  // Contain the locations of the keypoints from frame 1 in frame 2.
+  Keypoint frame2_keypoints_[kMaxKeypoints];
+
+  // The number of keypoints in frame 1.
+  int number_of_keypoints_;
+
+  // Keeps track of which keypoint correspondences were actually found from one
+  // frame to another.
+  // The i-th element of this array will be non-zero if and only if the i-th
+  // keypoint of frame 1 was found in frame 2.
+  bool optical_flow_found_keypoint_[kMaxKeypoints];
+
+ private:
+  TF_DISALLOW_COPY_AND_ASSIGN(FramePair);
+};
+
+}  // namespace tf_tracking
+
+#endif  // THIRD_PARTY_TENSORFLOW_EXAMPLES_ANDROID_JNI_OBJECT_TRACKING_FRAME_PAIR_H_