diff --git a/src/Rectangle/Tracking/RectangleTracker.cpp b/src/Rectangle/Tracking/RectangleTracker.cpp
new file mode 100755
index 0000000..0ffeb9b
--- /dev/null
+++ b/src/Rectangle/Tracking/RectangleTracker.cpp
@@ -0,0 +1,18 @@
+/*
+ * RectangleTracker.cpp
+ *
+ *  Created on: Apr 29, 2018
+ *      Author: yunya
+ */
+
+#include "RectangleTracker.h"
+
+RectangleTracker::RectangleTracker() {
+	// TODO Auto-generated constructor stub
+
+}
+
+RectangleTracker::~RectangleTracker() {
+	// TODO Auto-generated destructor stub
+}
+
diff --git a/src/Rectangle/Tracking/RectangleTracker.h b/src/Rectangle/Tracking/RectangleTracker.h
new file mode 100755
index 0000000..d0aa91d
--- /dev/null
+++ b/src/Rectangle/Tracking/RectangleTracker.h
@@ -0,0 +1,22 @@
+/*
+ * RectangleTracker.h
+ *
+ *  Created on: Apr 29, 2018
+ *      Author: yunya
+ */
+
+#ifndef RECTANGLE_RECTANGLETRACKER_H_
+#define RECTANGLE_RECTANGLETRACKER_H_
+#include <opencv2/core/utility.hpp>
+#include <opencv2/videoio.hpp>
+#include <opencv2/highgui.hpp>
+#include <iostream>
+
+class RectangleTracker {
+
+public:
+	RectangleTracker();
+	virtual ~RectangleTracker();
+};
+
+#endif /* RECTANGLE_RECTANGLETRACKER_H_ */
diff --git a/src/UI.cpp b/src/UI.cpp
new file mode 100755
index 0000000..add44be
--- /dev/null
+++ b/src/UI.cpp
@@ -0,0 +1,55 @@
+#include "UI.h"
+
+UI::UI(int *lastKey) {
+	this->lastKey = lastKey;
+}
+
+void UI::render() {
+	if (state < frames.size()) {
+		frames.resize(state+1);
+	}
+	state = 0;
+	cv::imshow("Normal", frames[0]);
+	if (debug) {
+		cv::imshow("debug", frames[debugFrame]);
+		if (showSlider) {
+
+		}
+	}
+
+	if (*lastKey == 100) {
+		debug = !debug;
+	}
+
+	if (debug) {
+		if (*lastKey == 110) {
+			nextDebugFrame();
+		}
+	}
+}
+
+cv::Mat* UI::nextFrame() {
+	state++;
+	if (state+1 > frames.size()) {
+		frames.push_back(cv::Mat{});
+	}
+	return &(frames[state]);
+}
+
+cv::Mat* UI::currentFrame(int offset) {
+	return &(frames[state + offset]);
+}
+
+void UI::nextDebugFrame() {
+	debugFrame++;
+	if (debugFrame > frames.size()-1) {
+		debugFrame = 0;
+	}
+}
+
+void UI::setOriginalFrame(cv::Mat frame) {
+	frames[0] = frame;
+}
+
+UI::~UI() {
+}
diff --git a/src/UI.h b/src/UI.h
new file mode 100755
index 0000000..95471e2
--- /dev/null
+++ b/src/UI.h
@@ -0,0 +1,31 @@
+/*
+ * UI.h
+ *
+ *  Created on: May 5, 2018
+ *      Author: Yunyang
+ */
+
+#ifndef UI_H_
+#define UI_H_
+#include <opencv2/opencv.hpp>
+
+class UI {
+	bool debug = false, showSlider = false;
+	unsigned debugFrame = 0;
+	int *lastKey;
+	unsigned state = 0;
+	std::vector<cv::Mat> frames = {cv::Mat()};
+	std::vector<void(*)()> debugAddonStarter;
+public:
+	UI(int *lastKey);
+	void render();
+	void nextDebugFrame();
+	cv::Mat* nextFrame();
+	cv::Mat* currentFrame(int offset);
+
+	void setOriginalFrame(cv::Mat frame);
+
+	virtual ~UI();
+};
+
+#endif /* UI_H_ */